public class Dialect extends MySQLInnoDBDialect {
public Dialect() {
super();
registerFunction( "date_add_interval", new SQLFunctionTemplate( Hibernate.DATE, "date_add(?1, INTERVAL ?2 ?3)" ) );
}
}
Modified HQL
allotment.date >= DATE_FORMAT( date_add_interval(:currentDateTime, supplier_leadtimes, HOUR), '%Y-%m-%d')
Friday, June 27, 2008
Explain SSL
Its... Secure Sockets Layer, a protocol developed by Netscape for transmitting private documents via the Internet. SSL uses a cryptographic system that uses two keys to encrypt data − a public key known to everyone and a private or secret key known only to the recipient of the message. Both Netscape Navigator and Internet Explorer support SSL, and many Web sites use the protocol to obtain confidential user information, such as credit card numbers.By convention, URLs that require an SSL connection start with https: instead of http:. There is - another protocol for transmitting data securely over the World Wide Web is Secure HTTP (S-HTTP). Whereas SSL creates a secure connection between a client and a server, over which any amount of data can be sent securely, S-HTTP is designed to transmit individual messages securely.
Which method is used for Data transfer?
Asynchronous Connectionless (ACL) is Data transfer method in Bluetooth
There r 2 types of data transformation technique.1 is synchronous data transformation & 2nd is asynchronous data transformation. with the help of these technique we can transfer a data.
There r 2 types of data transformation technique.1 is synchronous data transformation & 2nd is asynchronous data transformation. with the help of these technique we can transfer a data.
Advantages and disadvantages of attributes.
1.if more than one attribute has sane name then it will create the problem.
2.Attribute is the common media through which we can get the information about a entity.
2.Attribute is the common media through which we can get the information about a entity.
How we can count duplicate entery in particular table against Primary Key ? What are constraints?
The syntax in the previous answer (where count(*) > 1) is very questionable. suppose you think that you have duplicate employee numbers. there's no need to count them to find out which values were duplicate but the followin SQL will show only the empnos that are duplicate and how many exist in the table:
Select empno, count(*)
from employee
group by empno
having count(*) > 1
Generally speaking aggregate functions (count, sum, avg etc.) go in the HAVING clause. I know some systems allow them in the WHERE clause but you must be very careful in interpreting the result. WHERE COUNT(*) > 1 will absolutely NOT work in DB2 or ORACLE. Sybase and SQLServer is a different animal.
Select empno, count(*)
from employee
group by empno
having count(*) > 1
Generally speaking aggregate functions (count, sum, avg etc.) go in the HAVING clause. I know some systems allow them in the WHERE clause but you must be very careful in interpreting the result. WHERE COUNT(*) > 1 will absolutely NOT work in DB2 or ORACLE. Sybase and SQLServer is a different animal.
What are the advantages of mysql comparing with oracle?
MySql has many advantages in comparison to Oracle.
1 - MySql is Open source, which can be available any time
2 - MySql has no cost of development purpose.
3 - MySql has most of features , which oracle provides
4 - MySql day by day updating with new facilities.
5 - Good for small application.
6 - easy to learn and to become master.
7 - MySql has a good power these days.
even though MySql having so many advantages, Oracle is best database ever in Software development.
1 - MySql is Open source, which can be available any time
2 - MySql has no cost of development purpose.
3 - MySql has most of features , which oracle provides
4 - MySql day by day updating with new facilities.
5 - Good for small application.
6 - easy to learn and to become master.
7 - MySql has a good power these days.
even though MySql having so many advantages, Oracle is best database ever in Software development.
What r the disadvantages of struts?
Few Disadvantage are mentioned in the below link. Struts have disadvantages mainly on performance of the application. Especially when using advanced tag like nested-loop etc, Resulting in creating many Forms object then required.
http://www.coreservlets.com/Apache-Struts-Tutorial/Understanding-Struts.html
http://www.coreservlets.com/Apache-Struts-Tutorial/Understanding-Struts.html
How to display nth highest record in a table for example?How to display 4th highest (salary) record from customer table?
Query: SELECT sal FROM `emp` order by sal desc limit (n-1),1If the question: "how to display 4th highest (salary) record from customer table."The query will SELECT sal FROM `emp` order by sal desc limit 3,1
select sal from emp order by descending where rownum=4
select sal from emp order by descending where rownum=4
How do i configure web.xml using with struts.
Sturts framework use 2 types of configuration files: web.xml & struts-cofig.xmlConfiguaring web.xml for Struts is:2- steps are involved in this process1)Add .tld file in the web.xml. Eg: if you are using html file add strtus-html.tld in /WEB-INF/struts-html.tld/WEB-INF/struts-html.tld2) Configuring Action Servlet which wil recieve all incoming requests.Use Servet element to configure the instance of servlet & later can be mapped in the servlet mapping using some name the class name some name *.do
How to connect mysql from jsp(Java Server Page)?
<%
String connectionURL = "jdbc:mysql://localhost:3306/database_name";
Connection connection = null;
Statement statement = null;
Class.forName("com.mysql.jdbc.Driver").newInstance();
connection = DriverManager.getConnection(connectionURL, "database_username", "database_password");
statement = connection.createStatement();
%>
String connectionURL = "jdbc:mysql://localhost:3306/database_name";
Connection connection = null;
Statement statement = null;
Class.forName("com.mysql.jdbc.Driver").newInstance();
connection = DriverManager.getConnection(connectionURL, "database_username", "database_password");
statement = connection.createStatement();
%>
Working with JSTL TAGS - javaWorking with JSTL TAGS - java
JSTL Examples
(last updated: Dec 15, 2006)
Select font size:
8pt 9pt 10pt 11pt 12pt 14pt 16pt
Download the
JSTLexamples.war
archive. This archive contains the following files:
index.jsp Script with a variety of examples
bean/MyBean.java User-defined bean example
mytaglib/MyFunctions.java JSTL tag library classes
Functions.tld JSTL tag library definition
Install and run in Eclipse
Prior to starting eclipse, you need to make available two new library JAR files which are included in the apache-tomcat distribution but not available for all applications. Locate the directory:
apache-tomcat-6.0.14/webapps/jsp-examples/WEB-INF/lib/
and within it, the files:
jstl.jar standard.jar
Simply copy these two files into:
apache-tomcat-6.0.14/common/lib/
Then start up eclipse. Follow the steps in JSP Forms import the WAR file JSTLexamples.war and run the project on Tomcat.
The JSP Standard Tag Library (JSTL)
The JSTL library provides a means, through variables, expressions and tags, to avoid the interleaving of Java and tag-style code. Using this language, we can, for the most part, eliminate explicit Java code in JSP pages in favor of augmenting the XML-like tag structure. See
http://jakarta.apache.org/taglibs/
http://java.sun.com/products/jsp/jstl/1.1/docs/tlddocs/
You should refer to this online documentation:
jstl tld docs
and/or download it yourself:
jstl-1_1-mr2-spec-tlddoc.zip
The standard tags are those described in the table below. We have omitted the sql tags since we don’t plan to use SQL done directly in JSP. Using one of tag groups is effected by the addition of one of the following respective tag statements below.
c: <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
fn: <%@taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
fmt: <%@taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
xml: <%@taglib prefix="x" uri="http://java.sun.com/jsp/jstl/xml" %>
The uri is simply an identifier of the tag set. The prefix is determinable by the user, but the prefixes seen here are standard.
TLD tags and functions c: core fmt: formatting fn: functions x: xml
c:catch
c:choose
c:forEach
c:forTokens
c:if
c:import
c:otherwise
c:out
c:param
c:redirect
c:remove
c:set
c:url
c:when
fmt:bundle
fmt:formatDate
fmt:formatNumber
fmt:message
fmt:param
fmt:parseDate
fmt:parseNumber
fmt:requestEncoding
fmt:setBundle
fmt:setLocale
fmt:setTimeZone
fmt:timeZone
fn:contains()
fn:containsIgnoreCase()
fn:endsWith()
fn:escapeXml()
fn:indexOf()
fn:join()
fn:length()
fn:replace()
fn:split()
fn:startsWith()
fn:substring()
fn:substringAfter()
fn:substringBefore()
fn:toLowerCase()
fn:toUpperCase()
fn:trim()
x:choose
x:forEach
x:if
x:otherwise
x:out
x:param
x:parse
x:set
x:transform
x:when
These and other tag systems are used in JSP in one of two forms:
or, as functions to create expressions:
tag-prefix:function(arg1,arg2,...)
As in XML, tags can be complete, using a single tag ending with “/>“, or in pairs, containing a content terminated by a matching ending tag . Some example of the common usages of the “c” tags are these:
...
...
Expression Language (EL)
The syntax for what replaces the “…” above is specified by a Java-like language, unimaginately called Expression Language (EL). EL is part of JSP; its expressions are all surrounded by the syntax ${ }. but typically can only be used most effectively in conjunction with JSTL tags. EL is closely related to Java but has some extensions and conceptual simplifications. In particular, EL is more like other web script languages being loosely typed along with other semantic simplifications. EL expressions permit variables and most of the usual arithmetic and boolean operators. Here are some points:
* The == operator for strings functions like the Java .equals operator.
* an EL expression with an undefined value, which (normally represented by null in Java) is also represented by null in EL, but is equivalent to the empty string.
* EL has a unary operator empty: empty(x) acts like the expression x==null but also means “x equals the empty string”.
* the operators or, and are synonyms for ||, &&, respectively.
Query parameters
The value of the parameter “xx” is expressed by the EL expression param.xx. When used directly in HTML,
${param.xx}
is equivalent to the JSP expression:
<%= (request.getParameter("xx") != null) ? (request.getParameter("xx") : "" %>
Session variables are EL variables
A session variable x automatically becomes available as an EL variable, e.g. if we have:
<%
session.setAttribute( "x", "hello" );
// or
pageContext.setAttribute( "x", "hello" );
%>
...
x = ${x}
${x}
When using a map, the iteration generates Map.Entry pairs. Using the getKey and getValue functions the structure of the JSTL code to iteratively print the key/value pairs looks like this:
${x.key}: ${x.value}
Choice tags c:if, c:choose/c:when
The c:if tag generates a choice situation with a syntax like:
...
The EL_BOOLEAN_EXPRESSION uses the usual boolean operators with simplifications and additions as mentioned above. If-else structures are based on the c:choose/c:when/c:otherwise tags:
...
...
...
...
User-generated tag functions
If one wants to avoid explicit JSP sections of code then the Java classes and functions must be able to be accessed through the tag system. Beans provide a limited way of doing so through combinations of “get/set” member functions, but this is not intended for utility functions to manipulate objects. The fn tags provide some of these utility functions, but one can imagine that soon there would be need for your own specific utility functions. Towards this end, JSP provides a means to add your own tag libraries using a combination of Java classes and Tag Library Definition (TLD) files. Both XML-like tags and EL function tags can be added, but it’s much easier to create user-defined EL function tags. The utility functions used must be static functions. For example, suppose we want to use the function defined in this class in an EL expression.
mytaglib/MyFunctions.java
package mytaglib;
import java.util.*;
public class MyFunctions {
public static boolean contains(Set set, String target) {
return set.contains(target);
}
}
The glue which connects this functions to JSP is the XML file MyTags.tld held stored in the /WEB-INF/ project directory.
MyTags.tld
1.1
/WEB-INF/MyTags
contains
mytaglib.MyFunctions
boolean contains(java.util.Set,java.lang.String)
This file defines a uri by which it is accessed and a set of function prototypes in XML format. Each function has a tag name, the class it belongs to and the actual function prototype within this class. The necessary specification within the JSP file is something like this:
<%@taglib prefix="mtg" uri="/WEB-INF/MyTags"%>
The prefix chosen specifies how the function will be referenced within the EL syntax — it can be anything you want, so long as it doesn’t conflict with another tag set. In this case the function will be prefaced by mtg: as in this example:
...
Example script
index.jsp
<%@ page language=”java” contentType=”text/html;
charset=US-ASCII” pageEncoding=”US-ASCII”%>
<%@page import=”java.util.*”%>
<%@taglib prefix=”c” uri=”http://java.sun.com/jsp/jstl/core”%>
<%@taglib prefix=”fn” uri=”http://java.sun.com/jsp/jstl/functions”%>
<%@taglib prefix=”mtg” uri=”/WEB-INF/MyTags”%>
Insert title here
<%
String x = “testing”;
String[] a = { “xx”, “yy”, “zz” };
Map m = new LinkedHashMap();
m.put(”aa”, “1″);
m.put(”bb”, “2″);
m.put(”cc”, “3″);
List l = new ArrayList();
l.add(”nn”);
l.add(”mm”);
l.add(”oo”);
Set s = new LinkedHashSet();
s.add(”aa”);
s.add(”bb”);
s.add(”cc”);
session.setAttribute(”x”, x);
session.setAttribute(”a”, a);
session.setAttribute(”m”, m);
session.setAttribute(”l”, l);
session.setAttribute(”s”, s);
%>
param.p not defined
first value: ${param.p}
all values: ${fn:join(paramValues.p,”,”)}
x: ${x}
m: ${m}
s: ${s}
l: ${l}
a: ${fn:join(a,”,”)}
a[1]: ${a[1]}
m["bb"]: ${m["bb"]}
a:${i}
s:${i}
l:${i}
m:${i.key}=>${i.value}
bold” />
k: ${k}
escaped(k): ${fn:escapeXml(k)}
c:out escaped:
mb.count: ${mb.count}:
6}”>
became bigger than 6, re-initialize mb
3}”>became bigger than 3
no more than 3
s: ${s}
s.contains(${t}): ${mtg:contains(s,t)}
s.contains(${t}): ${mtg:contains(s,t)}
(last updated: Dec 15, 2006)
Select font size:
8pt 9pt 10pt 11pt 12pt 14pt 16pt
Download the
JSTLexamples.war
archive. This archive contains the following files:
index.jsp Script with a variety of examples
bean/MyBean.java User-defined bean example
mytaglib/MyFunctions.java JSTL tag library classes
Functions.tld JSTL tag library definition
Install and run in Eclipse
Prior to starting eclipse, you need to make available two new library JAR files which are included in the apache-tomcat distribution but not available for all applications. Locate the directory:
apache-tomcat-6.0.14/webapps/jsp-examples/WEB-INF/lib/
and within it, the files:
jstl.jar standard.jar
Simply copy these two files into:
apache-tomcat-6.0.14/common/lib/
Then start up eclipse. Follow the steps in JSP Forms import the WAR file JSTLexamples.war and run the project on Tomcat.
The JSP Standard Tag Library (JSTL)
The JSTL library provides a means, through variables, expressions and tags, to avoid the interleaving of Java and tag-style code. Using this language, we can, for the most part, eliminate explicit Java code in JSP pages in favor of augmenting the XML-like tag structure. See
http://jakarta.apache.org/taglibs/
http://java.sun.com/products/jsp/jstl/1.1/docs/tlddocs/
You should refer to this online documentation:
jstl tld docs
and/or download it yourself:
jstl-1_1-mr2-spec-tlddoc.zip
The standard tags are those described in the table below. We have omitted the sql tags since we don’t plan to use SQL done directly in JSP. Using one of tag groups is effected by the addition of one of the following respective tag statements below.
c: <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
fn: <%@taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
fmt: <%@taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
xml: <%@taglib prefix="x" uri="http://java.sun.com/jsp/jstl/xml" %>
The uri is simply an identifier of the tag set. The prefix is determinable by the user, but the prefixes seen here are standard.
TLD tags and functions c: core fmt: formatting fn: functions x: xml
c:catch
c:choose
c:forEach
c:forTokens
c:if
c:import
c:otherwise
c:out
c:param
c:redirect
c:remove
c:set
c:url
c:when
fmt:bundle
fmt:formatDate
fmt:formatNumber
fmt:message
fmt:param
fmt:parseDate
fmt:parseNumber
fmt:requestEncoding
fmt:setBundle
fmt:setLocale
fmt:setTimeZone
fmt:timeZone
fn:contains()
fn:containsIgnoreCase()
fn:endsWith()
fn:escapeXml()
fn:indexOf()
fn:join()
fn:length()
fn:replace()
fn:split()
fn:startsWith()
fn:substring()
fn:substringAfter()
fn:substringBefore()
fn:toLowerCase()
fn:toUpperCase()
fn:trim()
x:choose
x:forEach
x:if
x:otherwise
x:out
x:param
x:parse
x:set
x:transform
x:when
These and other tag systems are used in JSP in one of two forms:
or, as functions to create expressions:
tag-prefix:function(arg1,arg2,...)
As in XML, tags can be complete, using a single tag ending with “/>“, or in pairs, containing a content terminated by a matching ending tag . Some example of the common usages of the “c” tags are these:
Expression Language (EL)
The syntax for what replaces the “…” above is specified by a Java-like language, unimaginately called Expression Language (EL). EL is part of JSP; its expressions are all surrounded by the syntax ${ }. but typically can only be used most effectively in conjunction with JSTL tags. EL is closely related to Java but has some extensions and conceptual simplifications. In particular, EL is more like other web script languages being loosely typed along with other semantic simplifications. EL expressions permit variables and most of the usual arithmetic and boolean operators. Here are some points:
* The == operator for strings functions like the Java .equals operator.
* an EL expression with an undefined value, which (normally represented by null in Java) is also represented by null in EL, but is equivalent to the empty string.
* EL has a unary operator empty: empty(x) acts like the expression x==null but also means “x equals the empty string”.
* the operators or, and are synonyms for ||, &&, respectively.
Query parameters
The value of the parameter “xx” is expressed by the EL expression param.xx. When used directly in HTML,
${param.xx}
is equivalent to the JSP expression:
<%= (request.getParameter("xx") != null) ? (request.getParameter("xx") : "" %>
Session variables are EL variables
A session variable x automatically becomes available as an EL variable, e.g. if we have:
<%
session.setAttribute( "x", "hello" );
// or
pageContext.setAttribute( "x", "hello" );
%>
...
x = ${x}
${x}
When using a map, the iteration generates Map.Entry pairs. Using the getKey and getValue functions the structure of the JSTL code to iteratively print the key/value pairs looks like this:
${x.key}: ${x.value}
Choice tags c:if, c:choose/c:when
The c:if tag generates a choice situation with a syntax like:
The EL_BOOLEAN_EXPRESSION uses the usual boolean operators with simplifications and additions as mentioned above. If-else structures are based on the c:choose/c:when/c:otherwise tags:
...
User-generated tag functions
If one wants to avoid explicit JSP sections of code then the Java classes and functions must be able to be accessed through the tag system. Beans provide a limited way of doing so through combinations of “get/set” member functions, but this is not intended for utility functions to manipulate objects. The fn tags provide some of these utility functions, but one can imagine that soon there would be need for your own specific utility functions. Towards this end, JSP provides a means to add your own tag libraries using a combination of Java classes and Tag Library Definition (TLD) files. Both XML-like tags and EL function tags can be added, but it’s much easier to create user-defined EL function tags. The utility functions used must be static functions. For example, suppose we want to use the function defined in this class in an EL expression.
mytaglib/MyFunctions.java
package mytaglib;
import java.util.*;
public class MyFunctions {
public static boolean contains(Set
return set.contains(target);
}
}
The glue which connects this functions to JSP is the XML file MyTags.tld held stored in the /WEB-INF/ project directory.
MyTags.tld
boolean contains(java.util.Set,java.lang.String)
This file defines a uri by which it is accessed and a set of function prototypes in XML format. Each function has a tag name, the class it belongs to and the actual function prototype within this class. The necessary specification within the JSP file is something like this:
<%@taglib prefix="mtg" uri="/WEB-INF/MyTags"%>
The prefix chosen specifies how the function will be referenced within the EL syntax — it can be anything you want, so long as it doesn’t conflict with another tag set. In this case the function will be prefaced by mtg: as in this example:
Example script
index.jsp
<%@ page language=”java” contentType=”text/html;
charset=US-ASCII” pageEncoding=”US-ASCII”%>
<%@page import=”java.util.*”%>
<%@taglib prefix=”c” uri=”http://java.sun.com/jsp/jstl/core”%>
<%@taglib prefix=”fn” uri=”http://java.sun.com/jsp/jstl/functions”%>
<%@taglib prefix=”mtg” uri=”/WEB-INF/MyTags”%>
<%
String x = “testing”;
String[] a = { “xx”, “yy”, “zz” };
Map
m.put(”aa”, “1″);
m.put(”bb”, “2″);
m.put(”cc”, “3″);
List
l.add(”nn”);
l.add(”mm”);
l.add(”oo”);
Set
s.add(”aa”);
s.add(”bb”);
s.add(”cc”);
session.setAttribute(”x”, x);
session.setAttribute(”a”, a);
session.setAttribute(”m”, m);
session.setAttribute(”l”, l);
session.setAttribute(”s”, s);
%>
access values of query parameter p
first value: ${param.p}
all values: ${fn:join(paramValues.p,”,”)}
print objects
x: ${x}
m: ${m}
s: ${s}
l: ${l}
print array using join
a: ${fn:join(a,”,”)}
access individuals of array or map via [ ]
a[1]: ${a[1]}
m["bb"]: ${m["bb"]}
access individuals in c:forEach loop
a:
s:
l:
m:
using c:set and escapeXml
k: ${k}
escaped(k): ${fn:escapeXml(k)}
c:out escaped:
using a bean’s get and set properties indirectly
mb.count: ${mb.count}:
became bigger than 6, re-initialize mb
User defined tag functions
s: ${s}
s.contains(${t}): ${mtg:contains(s,t)}
s.contains(${t}): ${mtg:contains(s,t)}
How to run EXE files using Javascript
Here is the below code you can execute any exe files
How to run EXE files using Javascript
LANGUAGE=”javascript”
TYPE=”text/javascript”
>
function PROCTest() {
var myshell = new ActiveXObject( “WScript.shell” );
myshell.run( ‘”c:/program files/microsoft office/office11/excel.exe” “C:/server.xls”‘, 1, true );
}
TYPE=”button”
NAME=”button1″
VALUE=”Run Excel and start it with your filename”
ONCLICK=”PROCTest()”
>
LANGUAGE=”javascript”
TYPE=”text/javascript”
>
function PROCTest() {
var myshell = new ActiveXObject( “WScript.shell” );
myshell.run( ‘”c:/program files/microsoft office/office11/excel.exe” “C:/server.xls”‘, 1, true );
}
TYPE=”button”
NAME=”button1″
VALUE=”Run Excel and start it with your filename”
ONCLICK=”PROCTest()”
>
Using the window.open method — 3 methods to open window
Using the window.open method
The syntax of the window.open method is given below:
open (URL, windowName[, windowFeatures])
URL
The URL of the page to open in the new window. This argument could be blank.
windowName
A name to be given to the new window. The name can be used to refer this window again.
windowFeatures
A string that determines the various window features to be included in the popup window (like status bar, address bar etc)
The following code opens a new browser window with standard features.
window.open ("http://www.javascript-coder.com","mywindow");
Note: The popups created using ‘window.open()’ can get blocked by popup blockers.
Click here to find out how to create popups that does not get blocked.
Changing the features of the Popup
You can control the features of the popup using the last argument to the window.open method. The following code opens a window with a status bar and no extra features.
window.open ("http://www.javascript-coder.com","mywindow","status=1");
The code below opens a window with toolbar and status bar.
window.open ("http://www.javascript-coder.com",
"mywindow","status=1,toolbar=1");
The table shows the features and the string tokens you can use:
status The status bar at the bottom of the window.
toolbar The standard browser toolbar, with buttons such as Back and Forward.
location The Location entry field where you enter the URL.
menubar The menu bar of the window
directories The standard browser directory buttons, such as What’s New and What’s Cool
resizable Allow/Disallow the user to resize the window.
scrollbars Enable the scrollbars if the document is bigger than the window
height Specifies the height of the window in pixels. (example: height=’350′)
width Specifies the width of the window in pixels.
Examples
The following code opens a window with menu bar. The window is resizable and is having 350 pixels width and 250 pixels height.
window.open ("http://www.javascript-coder.com",
"mywindow","menubar=1,resizable=1,width=350,height=250");
Example 1
A window with location bar, status bar, scroll bar and of size 100 X 100
window.open ("http://www.javascript-coder.com",
"mywindow","location=1,status=1,scrollbars=1,
width=100,height=100");
Example 2
Moving the window to a desired location
You can use the window.moveTo function to move the popup window to a desired location.
The code below shows positioning the popup at a desired location
function mypopup()
{
mywindow = window.open ("http://www.javascript-coder.com",
"mywindow","location=1,status=1,scrollbars=1,
width=100,height=100");
mywindow.moveTo(0,0);
}
The code positions the popup on the top left corner of the screen.
Putting it all together
Now we will combine all these information to create the popup windows of different types.
The Code below opens a popup window when you enter the page:
JavaScript Popup Example 3
Notice that the URL is kept blank. This will open a blank window. You can see the code in work in this file:
JavaScript Popup Example 3
Popup On Exit
The following code pops up a window when the user exits a page.
JavaScript Popup Example 3
The code contains an extra line:
my_window.document.write('
This code displays a line ‘Popup Test!’ in the popup.
The code is available in the file:
JavaScript Popup Example 4
The next page shows you how to close a popup window.
The syntax of the window.open method is given below:
open (URL, windowName[, windowFeatures])
URL
The URL of the page to open in the new window. This argument could be blank.
windowName
A name to be given to the new window. The name can be used to refer this window again.
windowFeatures
A string that determines the various window features to be included in the popup window (like status bar, address bar etc)
The following code opens a new browser window with standard features.
window.open ("http://www.javascript-coder.com","mywindow");
Note: The popups created using ‘window.open()’ can get blocked by popup blockers.
Click here to find out how to create popups that does not get blocked.
Changing the features of the Popup
You can control the features of the popup using the last argument to the window.open method. The following code opens a window with a status bar and no extra features.
window.open ("http://www.javascript-coder.com","mywindow","status=1");
The code below opens a window with toolbar and status bar.
window.open ("http://www.javascript-coder.com",
"mywindow","status=1,toolbar=1");
The table shows the features and the string tokens you can use:
status The status bar at the bottom of the window.
toolbar The standard browser toolbar, with buttons such as Back and Forward.
location The Location entry field where you enter the URL.
menubar The menu bar of the window
directories The standard browser directory buttons, such as What’s New and What’s Cool
resizable Allow/Disallow the user to resize the window.
scrollbars Enable the scrollbars if the document is bigger than the window
height Specifies the height of the window in pixels. (example: height=’350′)
width Specifies the width of the window in pixels.
Examples
The following code opens a window with menu bar. The window is resizable and is having 350 pixels width and 250 pixels height.
window.open ("http://www.javascript-coder.com",
"mywindow","menubar=1,resizable=1,width=350,height=250");
Example 1
A window with location bar, status bar, scroll bar and of size 100 X 100
window.open ("http://www.javascript-coder.com",
"mywindow","location=1,status=1,scrollbars=1,
width=100,height=100");
Example 2
Moving the window to a desired location
You can use the window.moveTo function to move the popup window to a desired location.
The code below shows positioning the popup at a desired location
function mypopup()
{
mywindow = window.open ("http://www.javascript-coder.com",
"mywindow","location=1,status=1,scrollbars=1,
width=100,height=100");
mywindow.moveTo(0,0);
}
The code positions the popup on the top left corner of the screen.
Putting it all together
Now we will combine all these information to create the popup windows of different types.
The Code below opens a popup window when you enter the page:
JavaScript Popup Example 3
Notice that the URL is kept blank. This will open a blank window. You can see the code in work in this file:
JavaScript Popup Example 3
Popup On Exit
The following code pops up a window when the user exits a page.
JavaScript Popup Example 4
The code contains an extra line:
my_window.document.write('
Popup Test!
')This code displays a line ‘Popup Test!’ in the popup.
The code is available in the file:
JavaScript Popup Example 4
The next page shows you how to close a popup window.
« Previous — Next » Javascript Time functions
Get the Javascript Time
The Date object has been created and now we have a variable that holds the current date. To get the information we need to print out the date we have to utilize some or all of the following functions:
* getTime() - Number of milliseconds since 1/1/1970 @ 12:00 AM
* getSeconds() - Number of seconds (0-59)
* getMinutes() - Number of minutes (0-59)
* getHours() - Number of hours (0-23)
* getDay() - Day of the week(0-6). 0 = Sunday, … , 6 = Saturday
* getDate() - Day of the month (0-31)
* getMonth() - Number of month (0-11)
* getFullYear() - The four digit year (1970-9999)
Today’s Date
document.write(getDateStr())
//–>
June 19, 2008
Today’s Date including day of week
document.write(getDateStrWithDOW())
//–>
Thursday, June 19, 2008
Todays Date (short format)
var today = new Date()
var year = today.getYear()
if(year<1000) year+=1900
document.write((today.getMonth()+1) + “/” +
today.getDate() + “/” + (year+”").substring(2,4))
//–>
6/19/08
Todays Date (short format, full year)
var today = new Date()
var year = today.getYear()
if(year<1000) year+=1900
document.write((today.getMonth()+1) + “/” +
today.getDate() + “/” + year)
//–>
6/19/2008
Todays Date (short format, leading zeros)
var today = new Date()
var month = today.getMonth()+1
var year = today.getYear()
var day = today.getDate()
if(day<10) day = “0″ + day
if(month<10) month= “0″ + month
if(year<1000) year+=1900
document.write(month + “/” + day +
“/” + (year+”").substring(2,4))
//–>
06/19/08
Todays Date (short format, leading zeros, full year)
var today = new Date()
var month = today.getMonth()+1
var year = today.getYear()
var day = today.getDate()
if(day<10) day = “0″ + day
if(month<10) month= “0″ + month
if(year<1000) year+=1900
document.write(month + “/” + day +
“/” + year)
//–>
06/19/2008
Todays Date (European format)
var today = new Date()
var year = today.getYear()
if(year<1000) year+=1900
document.write(today.getDate() + “.” +
(today.getMonth()+1) + “.” + (year+”").substring(2,4))
//–>
19.6.08
Basic Date and Time
var curDateTime = new Date()
document.write(curDateTime)
//–>
Thu Jun 19 2008 12:02:04 GMT+0530 (India Standard Time)
Date and Time (24-hr format)
var curDateTime = new Date()
document.write(curDateTime.toLocaleString())
//–>
Thursday, 19 June, 2008 12:02
Basic GMT Date and Time
var curDateTime = new Date()
document.write(curDateTime.toGMTString())
//–>
Thu, 19 Jun 2008 06:32:04 GMT
Time in 12-hr format
var curDateTime = new Date()
var curHour = curDateTime.getHours()
var curMin = curDateTime.getMinutes()
var curSec = curDateTime.getSeconds()
var curAMPM = ” AM”
var curTime = “”
if (curHour >= 12){
curHour -= 12
curAMPM = ” PM”
}
if (curHour == 0) curHour = 12
curTime = curHour + “:”
+ ((curMin < 10) ? “0″ : “”) + curMin + “:”
+ ((curSec < 10) ? “0″ : “”) + curSec
+ curAMPM
document.write(curTime)
//–>
12:02:04 PM
Time in 24-hr format
var curDateTime = new Date()
var curHour = curDateTime.getHours()
var curMin = curDateTime.getMinutes()
var curSec = curDateTime.getSeconds()
var curTime =
((curHour < 10) ? “0″ : “”) + curHour + “:”
+ ((curMin < 10) ? “0″ : “”) + curMin + “:”
+ ((curSec < 10) ? “0″ : “”) + curSec
document.write(curTime)
//–>
12:02:04
Time for Specific Time Zone
// Copyright 1999, 2000 by Ray Stott
// OK to use if this copyright is included
// Script available at http://www.crays.com/jsc
var TimezoneOffset = -8 // adjust for time zone
var localTime = new Date()
var ms = localTime.getTime()
+ (localTime.getTimezoneOffset() * 60000)
+ TimezoneOffset * 3600000
var time = new Date(ms)
var hour = time.getHours()
var minute = time.getMinutes()
var second = time.getSeconds()
var curTime = “” + ((hour > 12) ? hour - 12 : hour)
if(hour==0) curTime = “12″
curTime += ((minute < 10) ? “:0″ : “:”) + minute
curTime += ((second < 10) ? “:0″ : “:”) + second
curTime += (hour >= 12) ? ” PM” : ” AM”
document.write(curTime + ” - US Pacific Time”)
//–>
10:32:04 PM - US Pacific Time
GMT Time
var curDateTime = new Date()
var curHour = curDateTime.getHours()
+ curDateTime.getTimezoneOffset()/60
if (curHour > 24) curHour -= 24
if (curHour < 0) curHour += 24
var curMin = curDateTime.getMinutes()
var curSec = curDateTime.getSeconds()
var curTime =
((curHour < 10) ? “0″ : “”) + curHour + “:”
+ ((curMin < 10) ? “0″ : “”) + curMin + “:”
+ ((curSec < 10) ? “0″ : “”) + curSec
document.write(curTime + ” GMT”)
//–>
06.5:02:04 GMT
Offset from GMT
var curDateTime = new Date()
document.write(”GMT Offset for your time zone is “)
document.write(-(curDateTime.getTimezoneOffset()/60))
//–>
GMT Offset for your time zone is 5.5
Days till Y3K
var today = new Date()
var targetDate = new Date(”01/01/3000″) //use full year
var timeBeforeTarget = Math.floor(( targetDate.getTime()
- today.getTime()) / 86400000)
var msg = “There are only ” + (timeBeforeTarget +1)
+ ” days until the year 3000.”
document.write(msg)
//–>
There are only 362151 days until the year 3000.
Days after a Certain Date
var today = new Date()
var targetDate = new Date(”12/31/1999″) //use full year
var timeAfterTarget = Math.floor(( today.getTime()
- targetDate.getTime() ) / 86400000)
var msg = “This is day number ” + timeAfterTarget + ” for this year.”
document.write(msg)
//–>
This is day number 3093 for this year.
Additional Information on These Scripts
All scripts are Y2K compliant.
The Basic Date and Time, Date and Time (24-hr format) and Basic GMT Date and Time are easy to implement but the results displayed will be different for different browsers and operating systems. All of the other scripts should display the same results for all browsers and operating systems.
The Time for a Specific Time Zone script can be set for any time zone by changing the TimeZoneOffset variable. If you don’t know your time zone offset, you can find it out by using the Offset from GMT script. You may need to change this value twice a year to adjust for Daylight Savings Time.
Days till Y3K script can be used for other important dates by changing the date that is used to initialize the targetDate variable. Likewise, The Days after a Certain Date script can be used to count the days after a different date by changing the date that is used to initialize the targetDate variable. It is also important that you specify these dates with the full year, ie 2000 rather than 00, to be Y2K compliant.
The Date object has been created and now we have a variable that holds the current date. To get the information we need to print out the date we have to utilize some or all of the following functions:
* getTime() - Number of milliseconds since 1/1/1970 @ 12:00 AM
* getSeconds() - Number of seconds (0-59)
* getMinutes() - Number of minutes (0-59)
* getHours() - Number of hours (0-23)
* getDay() - Day of the week(0-6). 0 = Sunday, … , 6 = Saturday
* getDate() - Day of the month (0-31)
* getMonth() - Number of month (0-11)
* getFullYear() - The four digit year (1970-9999)
Today’s Date
document.write(getDateStr())
//–>
June 19, 2008
Today’s Date including day of week
document.write(getDateStrWithDOW())
//–>
Thursday, June 19, 2008
Todays Date (short format)
var today = new Date()
var year = today.getYear()
if(year<1000) year+=1900
document.write((today.getMonth()+1) + “/” +
today.getDate() + “/” + (year+”").substring(2,4))
//–>
6/19/08
Todays Date (short format, full year)
var today = new Date()
var year = today.getYear()
if(year<1000) year+=1900
document.write((today.getMonth()+1) + “/” +
today.getDate() + “/” + year)
//–>
6/19/2008
Todays Date (short format, leading zeros)
var today = new Date()
var month = today.getMonth()+1
var year = today.getYear()
var day = today.getDate()
if(day<10) day = “0″ + day
if(month<10) month= “0″ + month
if(year<1000) year+=1900
document.write(month + “/” + day +
“/” + (year+”").substring(2,4))
//–>
06/19/08
Todays Date (short format, leading zeros, full year)
var today = new Date()
var month = today.getMonth()+1
var year = today.getYear()
var day = today.getDate()
if(day<10) day = “0″ + day
if(month<10) month= “0″ + month
if(year<1000) year+=1900
document.write(month + “/” + day +
“/” + year)
//–>
06/19/2008
Todays Date (European format)
var today = new Date()
var year = today.getYear()
if(year<1000) year+=1900
document.write(today.getDate() + “.” +
(today.getMonth()+1) + “.” + (year+”").substring(2,4))
//–>
19.6.08
Basic Date and Time
var curDateTime = new Date()
document.write(curDateTime)
//–>
Thu Jun 19 2008 12:02:04 GMT+0530 (India Standard Time)
Date and Time (24-hr format)
var curDateTime = new Date()
document.write(curDateTime.toLocaleString())
//–>
Thursday, 19 June, 2008 12:02
Basic GMT Date and Time
var curDateTime = new Date()
document.write(curDateTime.toGMTString())
//–>
Thu, 19 Jun 2008 06:32:04 GMT
Time in 12-hr format
var curDateTime = new Date()
var curHour = curDateTime.getHours()
var curMin = curDateTime.getMinutes()
var curSec = curDateTime.getSeconds()
var curAMPM = ” AM”
var curTime = “”
if (curHour >= 12){
curHour -= 12
curAMPM = ” PM”
}
if (curHour == 0) curHour = 12
curTime = curHour + “:”
+ ((curMin < 10) ? “0″ : “”) + curMin + “:”
+ ((curSec < 10) ? “0″ : “”) + curSec
+ curAMPM
document.write(curTime)
//–>
12:02:04 PM
Time in 24-hr format
var curDateTime = new Date()
var curHour = curDateTime.getHours()
var curMin = curDateTime.getMinutes()
var curSec = curDateTime.getSeconds()
var curTime =
((curHour < 10) ? “0″ : “”) + curHour + “:”
+ ((curMin < 10) ? “0″ : “”) + curMin + “:”
+ ((curSec < 10) ? “0″ : “”) + curSec
document.write(curTime)
//–>
12:02:04
Time for Specific Time Zone
// Copyright 1999, 2000 by Ray Stott
// OK to use if this copyright is included
// Script available at http://www.crays.com/jsc
var TimezoneOffset = -8 // adjust for time zone
var localTime = new Date()
var ms = localTime.getTime()
+ (localTime.getTimezoneOffset() * 60000)
+ TimezoneOffset * 3600000
var time = new Date(ms)
var hour = time.getHours()
var minute = time.getMinutes()
var second = time.getSeconds()
var curTime = “” + ((hour > 12) ? hour - 12 : hour)
if(hour==0) curTime = “12″
curTime += ((minute < 10) ? “:0″ : “:”) + minute
curTime += ((second < 10) ? “:0″ : “:”) + second
curTime += (hour >= 12) ? ” PM” : ” AM”
document.write(curTime + ” - US Pacific Time”)
//–>
10:32:04 PM - US Pacific Time
GMT Time
var curDateTime = new Date()
var curHour = curDateTime.getHours()
+ curDateTime.getTimezoneOffset()/60
if (curHour > 24) curHour -= 24
if (curHour < 0) curHour += 24
var curMin = curDateTime.getMinutes()
var curSec = curDateTime.getSeconds()
var curTime =
((curHour < 10) ? “0″ : “”) + curHour + “:”
+ ((curMin < 10) ? “0″ : “”) + curMin + “:”
+ ((curSec < 10) ? “0″ : “”) + curSec
document.write(curTime + ” GMT”)
//–>
06.5:02:04 GMT
Offset from GMT
var curDateTime = new Date()
document.write(”GMT Offset for your time zone is “)
document.write(-(curDateTime.getTimezoneOffset()/60))
//–>
GMT Offset for your time zone is 5.5
Days till Y3K
var today = new Date()
var targetDate = new Date(”01/01/3000″) //use full year
var timeBeforeTarget = Math.floor(( targetDate.getTime()
- today.getTime()) / 86400000)
var msg = “There are only ” + (timeBeforeTarget +1)
+ ” days until the year 3000.”
document.write(msg)
//–>
There are only 362151 days until the year 3000.
Days after a Certain Date
var today = new Date()
var targetDate = new Date(”12/31/1999″) //use full year
var timeAfterTarget = Math.floor(( today.getTime()
- targetDate.getTime() ) / 86400000)
var msg = “This is day number ” + timeAfterTarget + ” for this year.”
document.write(msg)
//–>
This is day number 3093 for this year.
Additional Information on These Scripts
All scripts are Y2K compliant.
The Basic Date and Time, Date and Time (24-hr format) and Basic GMT Date and Time are easy to implement but the results displayed will be different for different browsers and operating systems. All of the other scripts should display the same results for all browsers and operating systems.
The Time for a Specific Time Zone script can be set for any time zone by changing the TimeZoneOffset variable. If you don’t know your time zone offset, you can find it out by using the Offset from GMT script. You may need to change this value twice a year to adjust for Daylight Savings Time.
Days till Y3K script can be used for other important dates by changing the date that is used to initialize the targetDate variable. Likewise, The Days after a Certain Date script can be used to count the days after a different date by changing the date that is used to initialize the targetDate variable. It is also important that you specify these dates with the full year, ie 2000 rather than 00, to be Y2K compliant.
Replace new Lines
Replace new Lines
var varNotes = varNotes.replace(
// Replace out the new line character.
new RegExp( “\\n“, “g” ),
// Put in … so we can see a visual representation of where
// the new line characters were replaced out.
“
”
);
var varNotes = varNotes.replace(
// Replace out the new line character.
new RegExp( “\\n“, “g” ),
// Put in … so we can see a visual representation of where
// the new line characters were replaced out.
“
”
);
Add months to a date in java script
Here is a function addMonths to add months to a date in java script.
example for 6 months add to December 26, 2007:
Date.prototype.addMonths = function (n) {
var day = this.getDate();
this.setMonth(this.getMonth() + n);
return this;
}
var d = new Date(”December 26, 2007″);
alert(d.addMonths(6));
example for 6 months add to December 26, 2007:
Date.prototype.addMonths = function (n) {
var day = this.getDate();
this.setMonth(this.getMonth() + n);
return this;
}
var d = new Date(”December 26, 2007″);
alert(d.addMonths(6));
9 Ways to Make Your Site More Search Engine Friendly
Search engines want to lead users to the most relevant information that is available online for any given keyword.
So focus on the user and ask yourself the question, “Is my page the most relevant page for this keyword online?” If the answer is yes, and you offer the best content for this keyword then you are well on your way.
The only way to get top placement in search engines is to provide very compelling information. However, search engines don’t read information like humans do.
They follow specific rules. Follow these 9 rules to rapidly boost your ranking in search engines.
1) Optimize your URLs.
If you have not yet picked a domain name for your website, don’t try to go for “mykeyword.com.” Instead, try to pick a name that you want to build your company and/or a brand around.
Yes, having the keyword in your name might help a little but don’t sacrifice your company branding just because of your domain.
2) Optimize your page title.
Create a short relevant title (60 characters max). Have the keywords appear first and don’t add any stuff such as “home page” in the title tag.
3) Optimize your description metatag.
Add the SEO keywords to the meta tag description. The description should be 200 characters max.
4) Optimize your keyword metatag.
Add the SEO keywords to the meta tag keywords. Include 5 keyword phrases max.
Example:
5) Optimize your H1 & H2 headers.
The headline at the top of your page should use the H1 HTML header. The sub-headline should follow the H2 header. Include your SEO keywords in the headline and sub-headline. Example: h1. Enter headline with keyword phrase Example: h2. Enter sub-headline with keyword phrase
6) Optimize your keyword density.
Creating a keyword rich content page is a MUST. Be creative, write good content and make frequent use of the keywords you are optimizing for.
However, make sure that your keyword density never exceeds 5% for pages with long copy and 10% for pages with little copy. If they do, you might get penalized by the search engines.
To find out what the keyword density is on your page use this free Keyword Tool at http://www.seochat.com/seo-tools/keyword-density/
7) Spice up your SEO keywords.
Be sure to have your keywords appear at least once in bold, italics, and underlined in the copy. Again, do this once, but don’t over do it!
8) Move your keywords up.
Text towards the top of the page, such as in the first paragraph, counts for more than text further down the page. So, make sure that your keyword phrase is included towards the top of your page.
9) Use text links for site navigation.
Do not use image buttons for links. Using text links is far better. Search engines can’t read the text in images.
Search engines want to feed searchers the best information and so do you. Make sure you have the most content, feature it in a search engine friendly site.
We hope that the above tips have demonstrated that SEO does not have to be intimidating or very hard. Sure, there is a lot more that you can learn. For now just take it one step at a time.
So focus on the user and ask yourself the question, “Is my page the most relevant page for this keyword online?” If the answer is yes, and you offer the best content for this keyword then you are well on your way.
The only way to get top placement in search engines is to provide very compelling information. However, search engines don’t read information like humans do.
They follow specific rules. Follow these 9 rules to rapidly boost your ranking in search engines.
1) Optimize your URLs.
If you have not yet picked a domain name for your website, don’t try to go for “mykeyword.com.” Instead, try to pick a name that you want to build your company and/or a brand around.
Yes, having the keyword in your name might help a little but don’t sacrifice your company branding just because of your domain.
2) Optimize your page title.
Create a short relevant title (60 characters max). Have the keywords appear first and don’t add any stuff such as “home page” in the title tag.
3) Optimize your description metatag.
Add the SEO keywords to the meta tag description. The description should be 200 characters max.
4) Optimize your keyword metatag.
Add the SEO keywords to the meta tag keywords. Include 5 keyword phrases max.
Example:
5) Optimize your H1 & H2 headers.
The headline at the top of your page should use the H1 HTML header. The sub-headline should follow the H2 header. Include your SEO keywords in the headline and sub-headline. Example: h1. Enter headline with keyword phrase Example: h2. Enter sub-headline with keyword phrase
6) Optimize your keyword density.
Creating a keyword rich content page is a MUST. Be creative, write good content and make frequent use of the keywords you are optimizing for.
However, make sure that your keyword density never exceeds 5% for pages with long copy and 10% for pages with little copy. If they do, you might get penalized by the search engines.
To find out what the keyword density is on your page use this free Keyword Tool at http://www.seochat.com/seo-tools/keyword-density/
7) Spice up your SEO keywords.
Be sure to have your keywords appear at least once in bold, italics, and underlined in the copy. Again, do this once, but don’t over do it!
8) Move your keywords up.
Text towards the top of the page, such as in the first paragraph, counts for more than text further down the page. So, make sure that your keyword phrase is included towards the top of your page.
9) Use text links for site navigation.
Do not use image buttons for links. Using text links is far better. Search engines can’t read the text in images.
Search engines want to feed searchers the best information and so do you. Make sure you have the most content, feature it in a search engine friendly site.
We hope that the above tips have demonstrated that SEO does not have to be intimidating or very hard. Sure, there is a lot more that you can learn. For now just take it one step at a time.
Keep your website Fresh
What site would you prefer to go to? A site that has 100 pages of content but has not been updated in a year, or a 50 page site that keeps adding new content once a week?
Search engines think the same.
As you start to build out the content on your site, space it out and try to upload a new 200-500 word page every week.
Each one of these pages should go after a different keyword or keyword phrase. Use the top keywords from your PPC campaign.
We’ll repeat this point since it is so important: a website that is stagnant and has not changed content over the last year will never lead the pack in search engines.
What are the easiest ways to add fresh content to your page?
A) Build a site that is easy to update and change.
We recommend that you build your site in a modular way. Just think of a site built out of Lego blocks. Every page on your site will consist of a lot of Lego blocks and you can use the same Lego blocks on each of your pages.
Let’s say for example you want to change your top header. Most websites navigation bar at the top. If you are using a modular site that uses Lego blocks, then one Lego block would be for your top header. Now you can just update this one Lego block and the header on all of your 68 pages is automatically updated.
This will save you hours of work and make it far easier to update your pages and keep them fresh. Fortunately, you don’t have to be a programmer to use this. Building a modular site with Lego blocks is very easy. We cover this in detail in the module on Site Design.
B) Add dynamic content into your site.
Dynamic content is content that automatically keeps changing. In the past, adding dynamic content used to be very hard but with new advancements it has become super easy to do.
Here’s an easy way to get updated content into your website effortlessly. Let’s say that you are trying to build an expert site on “web design.”
In this case, you could go to a site such as BlinkList and automatically add the latest “web design tutorials” that people are finding online to your site. To do this, all you would have to do is:
1. Go to BlinkList
2. Look for the instructions on the sidebar to BROADCAST the content.
3. Copy and paste the javascript code that is provided by BlinkList into your site If you did the above, you would have a section on your site that would constantly show the latest web design tutorials that people are discovering online.
This is not only great content for site visitors but would also keep your site fresh and help significantly with SEO.
C) Attach a blog to your site.
Blogs are very easy to update and should be a key part of every search engine optimization. Search engines like Google love regularly updated, content-rich sites ‘ which is exactly what blogs are!
Most blogs are updated with new articles and information on a daily basis; over time the search engines recognize them for their wealth of information and boost their ranking.
Blogs also contain a rich supply of links. Since bloggers are always looking for ways to keep their blogs fresh, they are likely to use links rather than create all the content themselves.
Links to quality sites, including blog search engines and directories, can lead to high search engine rankings.
If you have a great site with excellent content that visitors love, this will start to work in your favor. If you are just spamming search engines and not providing value for the visitors, then Google will eventually catch up with you.
Bjorn Brands is a successfull enterprenuer who transitioned from having his own building company to a great online business. Check out his site and see for yourself how his FREE course can help you do the same at
Search engines think the same.
As you start to build out the content on your site, space it out and try to upload a new 200-500 word page every week.
Each one of these pages should go after a different keyword or keyword phrase. Use the top keywords from your PPC campaign.
We’ll repeat this point since it is so important: a website that is stagnant and has not changed content over the last year will never lead the pack in search engines.
What are the easiest ways to add fresh content to your page?
A) Build a site that is easy to update and change.
We recommend that you build your site in a modular way. Just think of a site built out of Lego blocks. Every page on your site will consist of a lot of Lego blocks and you can use the same Lego blocks on each of your pages.
Let’s say for example you want to change your top header. Most websites navigation bar at the top. If you are using a modular site that uses Lego blocks, then one Lego block would be for your top header. Now you can just update this one Lego block and the header on all of your 68 pages is automatically updated.
This will save you hours of work and make it far easier to update your pages and keep them fresh. Fortunately, you don’t have to be a programmer to use this. Building a modular site with Lego blocks is very easy. We cover this in detail in the module on Site Design.
B) Add dynamic content into your site.
Dynamic content is content that automatically keeps changing. In the past, adding dynamic content used to be very hard but with new advancements it has become super easy to do.
Here’s an easy way to get updated content into your website effortlessly. Let’s say that you are trying to build an expert site on “web design.”
In this case, you could go to a site such as BlinkList and automatically add the latest “web design tutorials” that people are finding online to your site. To do this, all you would have to do is:
1. Go to BlinkList
2. Look for the instructions on the sidebar to BROADCAST the content.
3. Copy and paste the javascript code that is provided by BlinkList into your site If you did the above, you would have a section on your site that would constantly show the latest web design tutorials that people are discovering online.
This is not only great content for site visitors but would also keep your site fresh and help significantly with SEO.
C) Attach a blog to your site.
Blogs are very easy to update and should be a key part of every search engine optimization. Search engines like Google love regularly updated, content-rich sites ‘ which is exactly what blogs are!
Most blogs are updated with new articles and information on a daily basis; over time the search engines recognize them for their wealth of information and boost their ranking.
Blogs also contain a rich supply of links. Since bloggers are always looking for ways to keep their blogs fresh, they are likely to use links rather than create all the content themselves.
Links to quality sites, including blog search engines and directories, can lead to high search engine rankings.
If you have a great site with excellent content that visitors love, this will start to work in your favor. If you are just spamming search engines and not providing value for the visitors, then Google will eventually catch up with you.
Bjorn Brands is a successfull enterprenuer who transitioned from having his own building company to a great online business. Check out his site and see for yourself how his FREE course can help you do the same at
The 8 Winning Elements Of The Successful Business Website
It is amazing how successful internet home business websites have so much in common. I have analyzed hundreds of times the websites of the best performing internet business owners and seen these similarities.
One common feature is that these successful sites are likable and somehow easy to use. Everything looks so clear, so it is easy to judge whether you like it or not.
They look so simple, that I often ask, what special they have and how they have become so successful? It seems that the simpler and the more user friendly the site is, the better chances it has to create big sales.
Very clearly one big success factor is that the finetuning work should concentrate to take away all the unnecessary elements and non-selling links.
1.Winning Element: Attention Grabbing Title.
The title is absolutely the most important element of the site. It should contain the promise and to describe the content of the site.
The job of the title is to persuade the visitor to continue and to find the things that are useful for him.
The headline should be written well and it should stand out from the rest of the copy. It also should be the first element, which catches the visitor attention in seconds, because if it does not do that, the visitor continues the surfing.
2.Winning Element: Well Written Copy.
The Internet is the information highway, so the role of the copy is very important, this is the world of the words. The copy should draw the readers attention immediately to the benefits your offer give to him.
The style is important and the target is to build up the trust from the first contact. The copy should make the reader enthusiastic about the benefits but it should not use hype style overpromises, because they will destroy the trust.
3.Winning Element: Easy Site Navigation.
This is the technical must, because nothing drives the visitors away faster than the bad navigation. The site structure should be clear and logical, so that the visitor knows all the time, where he is and to where he could go from here.
The menu should be the same on every page and clearly accessible and also easy to understand. The terms should be clear, despite of the fact that you may want to use internet home business keyphrases.
4.Winning Element: Call To Action.
After the copy has presented the main benefits it is the time to call the reader into action. Yes to tell him directly what to do and not to leave him guessing, how should I go on? Action is everything and we have to call the reader to do that.
One good way is to lower the bar, i.e. to offer a cheap or free trial opportunity for some weeks, before the reader will buy the product. The efficiency is the better, the more often you call the reader into action.
5. Winning Element: Images.
One picture tells more than thousand words. You should include photos of every product you sell, because they make the products more real, than the copy alone.
If you have lots of products for sale, you can use thumbnails that link to larger images. This speed up the page loadings.
6.Winning Element: Optin Form.
Most of the internet home business visitors needs at least five contacts before they will buy. However if they are interested about what you offer, it is important to get their name and email address through an optin form on the visible place of the site.
In this process you have to give them a gift, an email course, a free e-book or something like that, which again will sell your offer later on. Now you can send them messages during a long period of time, which clearly makes the process more productive.
7.Winning Element: About Us Section.
The idea of every internet home business site is to build trust over a long period of time. This requires that you tell enough about yourself and give your contact information for further questions.
An effective way is to use a picture about yourself and some information in the form of a story and underline your expertise as a marketer in this area. This shows people that there is a real people behind the business.
8.Winning Element: Site Freshness.
People and search engines love unique, fresh information. That is why you should update the content very often and change those parts that do not work anymore and add some elements which show right away that something new is available.
It is useful to look the competing sites in your internet home business niche, because they are a great source of new ideas. Another idea is to make sure your site can stand out from the crowd.
The marketing is very important but the key is still the quality of your internet home business site. It makes the people to come back and it is the real place, where they can reach you and your offers.
One common feature is that these successful sites are likable and somehow easy to use. Everything looks so clear, so it is easy to judge whether you like it or not.
They look so simple, that I often ask, what special they have and how they have become so successful? It seems that the simpler and the more user friendly the site is, the better chances it has to create big sales.
Very clearly one big success factor is that the finetuning work should concentrate to take away all the unnecessary elements and non-selling links.
1.Winning Element: Attention Grabbing Title.
The title is absolutely the most important element of the site. It should contain the promise and to describe the content of the site.
The job of the title is to persuade the visitor to continue and to find the things that are useful for him.
The headline should be written well and it should stand out from the rest of the copy. It also should be the first element, which catches the visitor attention in seconds, because if it does not do that, the visitor continues the surfing.
2.Winning Element: Well Written Copy.
The Internet is the information highway, so the role of the copy is very important, this is the world of the words. The copy should draw the readers attention immediately to the benefits your offer give to him.
The style is important and the target is to build up the trust from the first contact. The copy should make the reader enthusiastic about the benefits but it should not use hype style overpromises, because they will destroy the trust.
3.Winning Element: Easy Site Navigation.
This is the technical must, because nothing drives the visitors away faster than the bad navigation. The site structure should be clear and logical, so that the visitor knows all the time, where he is and to where he could go from here.
The menu should be the same on every page and clearly accessible and also easy to understand. The terms should be clear, despite of the fact that you may want to use internet home business keyphrases.
4.Winning Element: Call To Action.
After the copy has presented the main benefits it is the time to call the reader into action. Yes to tell him directly what to do and not to leave him guessing, how should I go on? Action is everything and we have to call the reader to do that.
One good way is to lower the bar, i.e. to offer a cheap or free trial opportunity for some weeks, before the reader will buy the product. The efficiency is the better, the more often you call the reader into action.
5. Winning Element: Images.
One picture tells more than thousand words. You should include photos of every product you sell, because they make the products more real, than the copy alone.
If you have lots of products for sale, you can use thumbnails that link to larger images. This speed up the page loadings.
6.Winning Element: Optin Form.
Most of the internet home business visitors needs at least five contacts before they will buy. However if they are interested about what you offer, it is important to get their name and email address through an optin form on the visible place of the site.
In this process you have to give them a gift, an email course, a free e-book or something like that, which again will sell your offer later on. Now you can send them messages during a long period of time, which clearly makes the process more productive.
7.Winning Element: About Us Section.
The idea of every internet home business site is to build trust over a long period of time. This requires that you tell enough about yourself and give your contact information for further questions.
An effective way is to use a picture about yourself and some information in the form of a story and underline your expertise as a marketer in this area. This shows people that there is a real people behind the business.
8.Winning Element: Site Freshness.
People and search engines love unique, fresh information. That is why you should update the content very often and change those parts that do not work anymore and add some elements which show right away that something new is available.
It is useful to look the competing sites in your internet home business niche, because they are a great source of new ideas. Another idea is to make sure your site can stand out from the crowd.
The marketing is very important but the key is still the quality of your internet home business site. It makes the people to come back and it is the real place, where they can reach you and your offers.
Web site security–SQL Injection
SQL Injection is one of the many web attack mechanisms used by hackers to steal data from organizations. It is perhaps one of the most common application layer attack techniques used today. It is the type of attack that takes advantage of improper coding of your web applications that allows hacker to inject SQL commands into say a login form to allow them to gain access to the data held within your database.
In essence, SQL Injection arises because the fields available for user input allow SQL statements to pass through and query the database directly.
SQL Injection is the hacking technique which attempts to pass SQL commands (statements) through a web application for execution by the backend database. If not sanitized properly, web applications may result in SQL Injection attacks that allow hackers to view information from the database and/or even wipe it out.
Such features as login pages, support and product request forms, feedback forms, search pages, shopping carts and the general delivery of dynamic content, shape modern websites and provide businesses with the means necessary to communicate with prospects and customers. These website features are all examples of web applications which may be either purchased off-the-shelf or developed as bespoke programs.
These website features are all susceptible to SQL Injection attacks which arise because the fields available for user input allow SQL statements to pass through and query the database directly.
Why is it possible to pass SQL queries directly to a database that is hidden behind a firewall and any other security mechanism?
Firewalls and similar intrusion detection mechanisms provide little or no defense against full-scale SQL Injection web attacks.
Since your website needs to be public, security mechanisms will allow public web traffic to communicate with your web application/s (generally over port 80/443). The web application has open access to the database in order to return (update) the requested (changed) information.
In SQL Injection, the hacker uses SQL queries and creativity to get to the database of sensitive corporate data through the web application.
SQL or Structured Query Language is the computer language that allows you to store, manipulate, and retrieve data stored in a relational database (or a collection of tables which organise and structure data). SQL is, in fact, the only way that a web application (and users) can interact with the database. Examples of relational databases include Oracle, Microsoft Access, MS SQL Server, MySQL, and Filemaker Pro, all of which use SQL as their basic building blocks.
SQL commands include SELECT, INSERT, DELETE and DROP TABLE. DROP TABLE is as ominous as it sounds and in fact will eliminate the table with a particular name.
Solution:
Securing your website and web applications from SQL Injection involves a three-part process:
1. Analysing the present state of security present by performing a thorough audit of your website and web applications for SQL Injection and other hacking vulnerabilities.
2. Making sure that you use coding best practice santising your web applications and all other components of your IT infrastructure.
3. Regularly performing a web security audit after each change and addition to your web components.
The best way to check whether your web site and applications are vulnerable to SQL injection attacks is by using an automated and heuristic web vulnerability scanner.
An automated web vulnerability scanner crawls your entire website and should automatically check for vulnerabilities to SQL Injection attacks. It will indicate which URLs/scripts are vulnerable to SQL injection so that you can immediately fix the code. Besides SQL injection vulnerabilities a web application scanner will also check for Cross site scripting and other web vulnerabilities.
In essence, SQL Injection arises because the fields available for user input allow SQL statements to pass through and query the database directly.
SQL Injection is the hacking technique which attempts to pass SQL commands (statements) through a web application for execution by the backend database. If not sanitized properly, web applications may result in SQL Injection attacks that allow hackers to view information from the database and/or even wipe it out.
Such features as login pages, support and product request forms, feedback forms, search pages, shopping carts and the general delivery of dynamic content, shape modern websites and provide businesses with the means necessary to communicate with prospects and customers. These website features are all examples of web applications which may be either purchased off-the-shelf or developed as bespoke programs.
These website features are all susceptible to SQL Injection attacks which arise because the fields available for user input allow SQL statements to pass through and query the database directly.
Why is it possible to pass SQL queries directly to a database that is hidden behind a firewall and any other security mechanism?
Firewalls and similar intrusion detection mechanisms provide little or no defense against full-scale SQL Injection web attacks.
Since your website needs to be public, security mechanisms will allow public web traffic to communicate with your web application/s (generally over port 80/443). The web application has open access to the database in order to return (update) the requested (changed) information.
In SQL Injection, the hacker uses SQL queries and creativity to get to the database of sensitive corporate data through the web application.
SQL or Structured Query Language is the computer language that allows you to store, manipulate, and retrieve data stored in a relational database (or a collection of tables which organise and structure data). SQL is, in fact, the only way that a web application (and users) can interact with the database. Examples of relational databases include Oracle, Microsoft Access, MS SQL Server, MySQL, and Filemaker Pro, all of which use SQL as their basic building blocks.
SQL commands include SELECT, INSERT, DELETE and DROP TABLE. DROP TABLE is as ominous as it sounds and in fact will eliminate the table with a particular name.
Solution:
Securing your website and web applications from SQL Injection involves a three-part process:
1. Analysing the present state of security present by performing a thorough audit of your website and web applications for SQL Injection and other hacking vulnerabilities.
2. Making sure that you use coding best practice santising your web applications and all other components of your IT infrastructure.
3. Regularly performing a web security audit after each change and addition to your web components.
The best way to check whether your web site and applications are vulnerable to SQL injection attacks is by using an automated and heuristic web vulnerability scanner.
An automated web vulnerability scanner crawls your entire website and should automatically check for vulnerabilities to SQL Injection attacks. It will indicate which URLs/scripts are vulnerable to SQL injection so that you can immediately fix the code. Besides SQL injection vulnerabilities a web application scanner will also check for Cross site scripting and other web vulnerabilities.
Web site security–Cross Site Scripting AttackWeb site security–Cross Site Scripting Attack
What is Cross site Scripting?
Hackers are constantly experimenting with a wide repertoire of hacking techniques to compromise websites and web applications and make off with a treasure trove of sensitive data including credit card numbers, social security numbers and even medical records.
In general, cross-site scripting refers to that hacking technique that leverages vulnerabilities in the code of a web application to allow an attacker to send malicious content from an end-user and collect some type of data from the victim.
Cross Site Scripting allows an attacker to embed malicious JavaScript, VBScript, ActiveX, HTML, or Flash into a vulnerable dynamic page to fool the user, executing the script on his machine in order to gather data. The use of XSS might compromise private information, manipulate or steal cookies, create requests that can be mistaken for those of a valid user, or execute malicious code on the end-user systems. The data is usually formatted as a hyperlink containing malicious content and which is distributed over any possible means on the internet.
Cross Site Scripting (also known as XSS or CSS) is generally believed to be one of the most common application layer hacking techniques.
In general, cross-site scripting refers to that hacking technique that leverages vulnerabilities in the code of a web application to allow an attacker to send malicious content from an end-user and collect some type of data from the victim.
As a hacking tool, the attacker can formulate and distribute a custom-crafted CSS URL just by using a browser to test the dynamic website response. The attacker also needs to know some HTML, JavaScript and a dynamic language, to produce a URL which is not too suspicious-looking, in order to attack a XSS vulnerable website.
Any web page which passes parameters to a database can be vulnerable to this hacking technique. Usually these are present in Login forms, Forgot Password forms, etc…
N.B. Often people refer to Cross Site Scripting as CSS or XSS, which is can be confused with Cascading Style Sheets (CSS).
Example of a Cross Site Scripting attack
As a simple example, imagine a search engine site which is open to an XSS attack. The query screen of the search engine is a simple single field form with a submit button. Whereas the results page, displays both the matched results and the text you are looking for.
Example:
Search Results for “XSS Vulnerability”
To be able to bookmark pages, search engines generally leave the entered variables in the URL address. In this case the URL would look like:
http://test.searchengine.com/search.php?q=XSS%20
Vulnerability
Next we try to send the following query to the search engine:
By submitting the query to search.php, it is encoded and the resulting URL would be something like:
http://test.searchengine.com/search.php?q=%3Cscript%3
Ealert%28%91This%20is%20an%20XSS%20Vulnerability%92%2
9%3C%2Fscript%3E
Upon loading the results page, the test search engine would probably display no results for the search but it will display a JavaScript alert which was injected into the page by using the XSS vulnerability.
Solution
To check for Cross site scripting vulnerabilities, use a Web Vulnerability Scanner. A Web Vulnerability Scanner crawls your entire website and automatically checks for Cross Site Scripting vulnerabilities. It will indicate which URLs/scripts are vulnerable to these attacks so that you can fix the vulnerability easily.
Web site security–CRLF Injection Attack
The term CRLF stands for Carriage Return (CR, ASCII 13, \r) Line Feed (LF, ASCII 10, \n). These are ACSII characters which display nothing on screen but are very widely used in Windows to indicate an end of line. On Linux/UNIX systems the end of line is indicated by the use of the Line Feed only.
This combination of CR and LR is used for example when pressing “Enter” on the keyboard. Depending on the application being used, pressing “Enter” generally instructs the application to start a new line, or to send a command.
A CRLF Injection attack occurs when a hacker manages to inject CRLF Commands into the system. This kind of attack is not a technological security hole in the Operating System or server software, but rather it depends on the way that a website is developed. Some developers are unaware of this kind of attack and leave open doors when developing web applications, allowing hackers to inject CRLF Commands.
In some types of websites, this flaw may be lethal to the application’s security. In other cases, this may just be a small bug with minimal priority. It all depends on whether this flaw allows the user to manipulate the web application.
Example of a CRLF Injection Attack
Many network protocols, including HTTP, make extensive use of the Carriage Return and Line Feed combination of commands since each line used in this protocol is separated by a CRLF. If a user is able to define an unfiltered HTTP header, it poses a risk since the user would then be able to communicate directly to the server, bypassing the application layer.
For example E-mail, News (NNTP) and HTTP headers are all based on the structure of “Key: Value” and each line is defined with a CRLF combination at the end. The “Location:” header is used in HTTP to redirect to another URL and a “Set-Cookie:” header is used for cookies. If these inputs are not properly validated, CR and LF characters can be embedded in the user input, and web scripts can be fooled to do other things than what they were originally constructed for.
If the input is not checked for CR and LF and the script constructs a redirect with the string:
Location: $url%0d%0a
We can redirect to a site while setting a cookie by setting $url (as one string) to:
http://www.i-was-redirected.com/%0d%0aSet-Cookie: Authenticated=yes%0d%0aReferer: www.somesite.com
If an attacker can save the URLs that another user will be redirected to, including cookies with important data, this can be serious.
Solution
The best way to defend against CRLF attacks it to filter extensively any input that a user can give. One should “remove everything but the known good data” and filter meta characters from the user input. This will ensure that only what should be entered in the field will be submitted to the server.
This combination of CR and LR is used for example when pressing “Enter” on the keyboard. Depending on the application being used, pressing “Enter” generally instructs the application to start a new line, or to send a command.
A CRLF Injection attack occurs when a hacker manages to inject CRLF Commands into the system. This kind of attack is not a technological security hole in the Operating System or server software, but rather it depends on the way that a website is developed. Some developers are unaware of this kind of attack and leave open doors when developing web applications, allowing hackers to inject CRLF Commands.
In some types of websites, this flaw may be lethal to the application’s security. In other cases, this may just be a small bug with minimal priority. It all depends on whether this flaw allows the user to manipulate the web application.
Example of a CRLF Injection Attack
Many network protocols, including HTTP, make extensive use of the Carriage Return and Line Feed combination of commands since each line used in this protocol is separated by a CRLF. If a user is able to define an unfiltered HTTP header, it poses a risk since the user would then be able to communicate directly to the server, bypassing the application layer.
For example E-mail, News (NNTP) and HTTP headers are all based on the structure of “Key: Value” and each line is defined with a CRLF combination at the end. The “Location:” header is used in HTTP to redirect to another URL and a “Set-Cookie:” header is used for cookies. If these inputs are not properly validated, CR and LF characters can be embedded in the user input, and web scripts can be fooled to do other things than what they were originally constructed for.
If the input is not checked for CR and LF and the script constructs a redirect with the string:
Location: $url%0d%0a
We can redirect to a site while setting a cookie by setting $url (as one string) to:
http://www.i-was-redirected.com/%0d%0aSet-Cookie: Authenticated=yes%0d%0aReferer: www.somesite.com
If an attacker can save the URLs that another user will be redirected to, including cookies with important data, this can be serious.
Solution
The best way to defend against CRLF attacks it to filter extensively any input that a user can give. One should “remove everything but the known good data” and filter meta characters from the user input. This will ensure that only what should be entered in the field will be submitted to the server.
Web site security–Directory Traversal Attacks
What is a Directory Traversal attack?
Properly controlling access to web content is crucial for running a secure web server. Directory Traversal is an HTTP exploit which allows attackers to access restricted directories and execute commands outside of the web server’s root directory.
Web servers provide two main levels of security mechanisms:
* Access Control Lists (ACLs)
* Root directory
An Access Control List is used in the authorization process. It is a list which the web server’s administrator uses to indicate which users or groups are able to access, modify or execute particular files on the server, as well as other access rights.
The root directory is a specific directory on the server file system in which the users are confined. Users are not able to access anything above this root.
For example: the default root directory of IIS on Windows is C:\Inetpub\wwwroot and with this setup, a user does not have access to C:\Windows but has access to C:\Inetpub\wwwroot\news and any other directories and files under the root directory (provided that the user is authenticated via the ACLs).
The root directory prevents users from accessing sensitive files on the server such as cmd.exe on Windows platforms and the passwd file on Linux/UNIX platforms.
This vulnerability can exist either in the web server software itself or in the web application code.
In order to perform a directory traversal attack, all an attacker needs is a web browser and some knowledge on where to blindly find any default files and directories on the system.
What an attacker can do if your site is vulnerable
With a system vulnerable to Directory Traversal, an attacker can make use of this vulnerability to step out of the root directory and access other parts of the file system. This might give the attacker the ability to view restricted files, or even more dangerous, allowing the attacker to execute powerful commands on the web server which can lead to a full compromise of the system.
Depending on how the website access is set up, the attacker will execute commands by impersonating himself as the user which is associated with “the website”. Therefore it all depends on what the website user has been given access to in the system.
Example of a directory traversal attack via web application code
In order to perform a directory traversal attack, all an attacker needs is a web browser and some knowledge on where to blindly find any default files and directories on the system.
Example of a directory traversal attack via web application code
In web applications with dynamic pages, input is usually received from browsers through GET or POST request methods. Here is an example of a GET HTTP request URL:
http://test.webarticles.com/show.asp?view=oldarchive.html
With this URL, the browser requests the dynamic page show.asp from the server and with it also sends the parameter “view” with the value of “oldarchive.html”. When this request is executed on the web server, show.asp retrieves the file oldarchive.htm from the server’s file system, renders it and then sends it back to the browser which displays it to the user. The attacker would assume that show.asp can retrieve files from the file system and sends this custom URL:
http://test.webarticles.com/show.asp?view=
../../../../../Windows/system.ini
This will cause the dynamic page to retrieve the file system.ini from the file system and display it to the user. The expression ../ instructs the system to go one directory up which is commonly used as an operating system directive. The attacker has to guess how many directories he has to go up to find the Windows folder on the system, but this is easily done by trial and error.
Example of a directory traversal attack via web server
Apart from vulnerabilities in the code, even the web server itself can be open to directory traversal attacks. The problem can either be incorporated into the web server software or inside some sample script files left available on the server.
The vulnerability has been fixed in the latest versions of web werver software, but there are web servers online which are still using older versions of IIS and Apache which might be open to directory traversal attacks. Even tough you might be using a web werver software version that has fixed this vulnerability, you might still have some sensitive default script directories exposed which are well known to hackers.
For example, a URL request which makes use of the scripts directory of IIS to traverse directories and execute a command can be:
http://server.com/scripts/..%5c../Windows/System32/
cmd.exe?/c+dir+c:\
The request would return to the user a list of all files in the C:\ directory by executing the cmd.exe command shell file and run the command “dir c:\” in the shell. The %5c expression that is in the URL request is a web server escape code which is used to represent normal characters. In this case %5c represents the character “\”.
Newer versions of modern web server software check for these escape codes and do not let them through. Some older versions however, do not filter out these codes in the root directory enforcer and will let the attackers execute such commands.
How to check for Directory Traversal vulnerabilities
The best way to check whether your web site & applications are vulnerable to Directory Traversal attacks is by using a Web Vulnerability Scanner. A Web Vulnerability Scanner crawls your entire website and automatically checks for Directory Traversal vulnerabilities. It will report the vulnerability and how to easily fix it.. Besides Directory Traversal vulnerabilities a web application scanner will also check for SQL injection, Cross site scripting & other web vulnerabilities.
Preventing directory traversal attacks
First of all, ensure you have installed the latest version of your web server software, and sure that all patches have been applied.
Secondly, effectively filter any user input. Ideally remove everything but the known good data and filter meta characters from the user input. This will ensure that only what should be entered in the field will be submitted to the server.
Web site security–Authentication Hacking Attacks
Authentication plays a critical role in the security of web applications. When a user provides his login name and password to authenticate and prove his identity, the application assigns the user specific privileges to the system, based on the identity established by the supplied credentials.
HTTP can embed several different types of authentication protocols. These include:
* Basic - Cleartext username/password, Base-64 encode (trivially decoded)
* Digest - Like Basic, but passwords are scrambled
* Form-based - A custom form is used to input username/password (or other credentials) and is processed using custom logic on the backend.
* NTLM - Microsoft’s proprietary authentication protocol, implemented within HTTP request/response headers.
* Negotiate - A new protocol from Microsoft that allows any type of authentication specified above to be dynamically agreed upon by the client and server. Also adds Kerberos for clients using Microsoft’s IE v5+.
* Client-side Certificates - Although rarely used, SSL/TLS provides an option that checks the authenticity of a digital certificate present by the Web client, essentially making it an authentication token.
* Microsoft Passport - A single-sign-in (SSI) service run by Microsoft Corporation that allows web sites (called “Passport Partners”) to authenticate users based on their membership in the Passport service. The mechanism uses a key shared between Microsoft and the Partner site to create a cookie that uniquely identifies the user.
These authentication protocols operate right over HTTP (or SSL/TSL), with credentials embedded right in the request/response traffic.
What an attacker can do if your site is vulnerable
When the attacker breaks into the system by proving to the application that he is a known and valid user, the attacker gains access to whatever privileges the administrator assigned that user.
This means that if the attacker manages to enter as a normal user, he might have limited access to only view some important information. On the other hand, if he manages to enter as an administrative user with global access on the system, he would have almost total control on the application together with its content (with the limitations of the web application in itself).
Here are some common Username/Passwords used by attackers in authentication guessing attacks:
Username Guesses
Password Guesses
[NULL]
[NULL]
root, administrator, admin
[NULL], root, administrator, admin, password, [company_name]
operator, webmaster, backup
[NULL], operator, webmaster, backup
guest, demo, test, trial
[NULL], guest, demo, test, trial
member, private
member, private
[company_name]
NULL], [company_name], password
[known_username]
[NULL], [known_username]
If password guessing achieves no result, the next step for an attacker is to try other password combinations using special custom tools, like WebCracker and Brutus, which are readily available on the internet.
These custom tools attempt to authenticate into the system using predefined lists of usernames and passwords, dictionary attacks and brute-force attacks. A dictionary attack uses pre-computed wordlists like dictionaries to try to authenticate on the web applications by trying thousands of combinations of these dictionary words as usernames and passwords.
A brute force attack is a method of defeating a cryptographic scheme by trying a large number of possibilities; for example, exhaustively working through all possible keys in order to decrypt a message.
Solution
Preventing Authentication Hacking attacks
To verify whether an attack phase has succeeded or not, automated tools assess the returned error codes and page information from the host web server. A secure practice is to force any error or unexpected request to generate a HTTP 200 OK response, instead of the numerous 400 type errors. This will make it more difficult for the attacker to distinguish between valid and invalid login attempts.
An important measure in stopping automated brute-force authentication attacks is by adding random content on the page presented to the authenticating client browser. The client must be capable of successfully submitting this random content as part of the authentication process to proceed further in the web site or application. The best way to do this is to present the random phrase in a graphic GIF, JPG or PNG format using random fonts or colours each time. This can make it almost impossible for an automated process to succeed. See screenshot below for an illustration.
HTTP can embed several different types of authentication protocols. These include:
* Basic - Cleartext username/password, Base-64 encode (trivially decoded)
* Digest - Like Basic, but passwords are scrambled
* Form-based - A custom form is used to input username/password (or other credentials) and is processed using custom logic on the backend.
* NTLM - Microsoft’s proprietary authentication protocol, implemented within HTTP request/response headers.
* Negotiate - A new protocol from Microsoft that allows any type of authentication specified above to be dynamically agreed upon by the client and server. Also adds Kerberos for clients using Microsoft’s IE v5+.
* Client-side Certificates - Although rarely used, SSL/TLS provides an option that checks the authenticity of a digital certificate present by the Web client, essentially making it an authentication token.
* Microsoft Passport - A single-sign-in (SSI) service run by Microsoft Corporation that allows web sites (called “Passport Partners”) to authenticate users based on their membership in the Passport service. The mechanism uses a key shared between Microsoft and the Partner site to create a cookie that uniquely identifies the user.
These authentication protocols operate right over HTTP (or SSL/TSL), with credentials embedded right in the request/response traffic.
What an attacker can do if your site is vulnerable
When the attacker breaks into the system by proving to the application that he is a known and valid user, the attacker gains access to whatever privileges the administrator assigned that user.
This means that if the attacker manages to enter as a normal user, he might have limited access to only view some important information. On the other hand, if he manages to enter as an administrative user with global access on the system, he would have almost total control on the application together with its content (with the limitations of the web application in itself).
Here are some common Username/Passwords used by attackers in authentication guessing attacks:
Username Guesses
Password Guesses
[NULL]
[NULL]
root, administrator, admin
[NULL], root, administrator, admin, password, [company_name]
operator, webmaster, backup
[NULL], operator, webmaster, backup
guest, demo, test, trial
[NULL], guest, demo, test, trial
member, private
member, private
[company_name]
NULL], [company_name], password
[known_username]
[NULL], [known_username]
If password guessing achieves no result, the next step for an attacker is to try other password combinations using special custom tools, like WebCracker and Brutus, which are readily available on the internet.
These custom tools attempt to authenticate into the system using predefined lists of usernames and passwords, dictionary attacks and brute-force attacks. A dictionary attack uses pre-computed wordlists like dictionaries to try to authenticate on the web applications by trying thousands of combinations of these dictionary words as usernames and passwords.
A brute force attack is a method of defeating a cryptographic scheme by trying a large number of possibilities; for example, exhaustively working through all possible keys in order to decrypt a message.
Solution
Preventing Authentication Hacking attacks
To verify whether an attack phase has succeeded or not, automated tools assess the returned error codes and page information from the host web server. A secure practice is to force any error or unexpected request to generate a HTTP 200 OK response, instead of the numerous 400 type errors. This will make it more difficult for the attacker to distinguish between valid and invalid login attempts.
An important measure in stopping automated brute-force authentication attacks is by adding random content on the page presented to the authenticating client browser. The client must be capable of successfully submitting this random content as part of the authentication process to proceed further in the web site or application. The best way to do this is to present the random phrase in a graphic GIF, JPG or PNG format using random fonts or colours each time. This can make it almost impossible for an automated process to succeed. See screenshot below for an illustration.
Web site security–Ajax security
Fuelled by the increased interest in Web 2.0, AJAX (Asynchronous JavaScript Technology and XML) is attracting the attention of businesses all round the globe.
AJAX is meant to increase interactivity, speed, and usability. The technologies have prompted a richer and friendly experience for the user as web applications are designed to imitate ‘traditional’ desktop applications.
There is the general misconception that in AJAX applications are more secure because it is thought that a user cannot access the server-side script without the rendered user interface (the AJAX based webpage). XML HTTP Request based web applications obscure server-side scripts, and this obscurity gives website developers and owners a false sense of security – obscurity is not security. Since XML HTTP requests function by using the same protocol as all else on the web (HTTP), technically speaking, AJAX-based web applications are vulnerable to the same hacking methodologies as ‘normal’ applications.
Another weakness of AJAX is the process that formulates server requests. The Ajax engine uses JS to capture the user commands and to transform them into function calls. Such function calls are sent in plain visible text to the server and may easily reveal database table fields such as valid product and user IDs, or even important variable names, valid data types or ranges, and any other parameters which may be manipulated by a hacker.
With this information, a hacker can easily use AJAX functions without the intended interface by crafting specific HTTP requests directly to the server. In case of cross-site scripting, maliciously injected scripts can actually leverage the AJAX provided functionalities to act on behalf of the user thereby tricking the user with the ultimate aim of redirecting his browsing session (e.g., phishing) or monitoring his traffic.
Solution
The only solution for effective and efficient security auditing is a vulnerability scanner which automates the crawling of websites to identify weaknesses. However, without an engine that parses and executes JavaScript, such crawling is inaccurate and gives website owners a false sense of security.
AJAX is meant to increase interactivity, speed, and usability. The technologies have prompted a richer and friendly experience for the user as web applications are designed to imitate ‘traditional’ desktop applications.
There is the general misconception that in AJAX applications are more secure because it is thought that a user cannot access the server-side script without the rendered user interface (the AJAX based webpage). XML HTTP Request based web applications obscure server-side scripts, and this obscurity gives website developers and owners a false sense of security – obscurity is not security. Since XML HTTP requests function by using the same protocol as all else on the web (HTTP), technically speaking, AJAX-based web applications are vulnerable to the same hacking methodologies as ‘normal’ applications.
Another weakness of AJAX is the process that formulates server requests. The Ajax engine uses JS to capture the user commands and to transform them into function calls. Such function calls are sent in plain visible text to the server and may easily reveal database table fields such as valid product and user IDs, or even important variable names, valid data types or ranges, and any other parameters which may be manipulated by a hacker.
With this information, a hacker can easily use AJAX functions without the intended interface by crafting specific HTTP requests directly to the server. In case of cross-site scripting, maliciously injected scripts can actually leverage the AJAX provided functionalities to act on behalf of the user thereby tricking the user with the ultimate aim of redirecting his browsing session (e.g., phishing) or monitoring his traffic.
Solution
The only solution for effective and efficient security auditing is a vulnerability scanner which automates the crawling of websites to identify weaknesses. However, without an engine that parses and executes JavaScript, such crawling is inaccurate and gives website owners a false sense of security.
How SSL Works
SSL certification
How authentication helps secure and improve e-commerce / e-business
SSL ensures safe transactions:
To make sure that no hacker can intercept and misuse information being collected online, SSL does two things:
* Encrypts it with a hidden key on the user’s computer before the information is sent out;
* Sends the key to the receiving computer using another encryption system called RSA. With this key the information collected online can be decoded.
* A 128-bit public encryption key and a 1024-bit private RSA key are unbreakable today. They are also part of most web browsers and web servers.
The SSL Process:
Each SSL Session ensures:
* Authenticity
* Data Integrity
* Data Privacy
How SSL Works:
1. Provides visible authentication:
Before an SSL session is established, the server it connects with needs to have a digital certificate – a kind of unique digital identification to establish its authenticity. Digital certificates are issued by a Certification Authority, after performing several checks to confirm the identity of the organization to which it is issuing the certificate.
An SSL digital certificate generates a public key for your customers and a private key on your server that works as a kind of official, online stamp for your enterprise. This private key needs to be kept secure, along with a back-up. A user can check to see if a secure session has been established by looking at the web address: in a secure session, the ‘http:’ portion of the web address changes to ‘https:’.
1. Assures data integrity:
This basically ensures that nobody can tamper with the data or information that is already online. Your customers will know that the contents of your website – or any information they have transmitted to it online – cannot be tampered with. It assures them that they are doing business in a safe environment.
1. Ensures data privacy:
This means that online collection of sensitive information is secure and cannot be intercepted or read by anyone except the computer it was intended for.
Data integrity and data privacy are integral to the functioning and success of any website handling or facilitating online financial transactions – and that’s what e-commerce is all about.
Once a secure session has been established, the public key is used by customers, to encrypt the information being sent online. This information is then decoded instantaneously through your server’s private key.
How authentication helps secure and improve e-commerce / e-business
SSL ensures safe transactions:
To make sure that no hacker can intercept and misuse information being collected online, SSL does two things:
* Encrypts it with a hidden key on the user’s computer before the information is sent out;
* Sends the key to the receiving computer using another encryption system called RSA. With this key the information collected online can be decoded.
* A 128-bit public encryption key and a 1024-bit private RSA key are unbreakable today. They are also part of most web browsers and web servers.
The SSL Process:
Each SSL Session ensures:
* Authenticity
* Data Integrity
* Data Privacy
How SSL Works:
1. Provides visible authentication:
Before an SSL session is established, the server it connects with needs to have a digital certificate – a kind of unique digital identification to establish its authenticity. Digital certificates are issued by a Certification Authority, after performing several checks to confirm the identity of the organization to which it is issuing the certificate.
An SSL digital certificate generates a public key for your customers and a private key on your server that works as a kind of official, online stamp for your enterprise. This private key needs to be kept secure, along with a back-up. A user can check to see if a secure session has been established by looking at the web address: in a secure session, the ‘http:’ portion of the web address changes to ‘https:’.
1. Assures data integrity:
This basically ensures that nobody can tamper with the data or information that is already online. Your customers will know that the contents of your website – or any information they have transmitted to it online – cannot be tampered with. It assures them that they are doing business in a safe environment.
1. Ensures data privacy:
This means that online collection of sensitive information is secure and cannot be intercepted or read by anyone except the computer it was intended for.
Data integrity and data privacy are integral to the functioning and success of any website handling or facilitating online financial transactions – and that’s what e-commerce is all about.
Once a secure session has been established, the public key is used by customers, to encrypt the information being sent online. This information is then decoded instantaneously through your server’s private key.
Web site security–Google hacking
What is Google hacking?
Google hacking is the term used when a hacker tries to find exploitable targets and sensitive data by using search engines. The Google Hacking Database (GHDB) is a database of queries that identify sensitive data. Although Google blocks some of the better known Google hacking queries, nothing stops a hacker from crawling your site and launching the Google Hacking Database queries directly onto the crawled content.
The Google Hacking Database is located at http://johnny.ihackstuff.com. More information about Google hacking can be found on: http://www.informit.com/articles/article.asp?p=170880&rl=1.
Google hacking is the term used when a hacker tries to find exploitable targets and sensitive data by using search engines. The Google Hacking Database (GHDB) is a database of queries that identify sensitive data. Although Google blocks some of the better known Google hacking queries, nothing stops a hacker from crawling your site and launching the Google Hacking Database queries directly onto the crawled content.
The Google Hacking Database is located at http://johnny.ihackstuff.com. More information about Google hacking can be found on: http://www.informit.com/articles/article.asp?p=170880&rl=1.
MySQL date function
11.6. Date and Time Functions
This section describes the functions that can be used to manipulate temporal values. See Section 10.3, “Date and Time Types”, for a description of the range of values each date and time type has and the valid formats in which values may be specified.
Name Description
ADDDATE()(v4.1.1)
Add dates
ADDTIME()(v4.1.1)
Add time
CONVERT_TZ()(v4.1.3)
Convert from one timezone to another
CURDATE()
Return the current date
CURRENT_DATE(), CURRENT_DATE
Synonyms for CURDATE()
CURRENT_TIME(), CURRENT_TIME
Synonyms for CURTIME()
CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP
Synonyms for NOW()
CURTIME()
Return the current time
DATE_ADD()
Add two dates
DATE_FORMAT()
Format date as specified
DATE_SUB()
Subtract two dates
DATE()(v4.1.1)
Extract the date part of a date or datetime expression
DATEDIFF()(v4.1.1)
Subtract two dates
DAY()(v4.1.1)
Synonym for DAYOFMONTH()
DAYNAME()(v4.1.21)
Return the name of the weekday
DAYOFMONTH()
Return the day of the month (1-31)
DAYOFWEEK()
Return the weekday index of the argument
DAYOFYEAR()
Return the day of the year (1-366)
EXTRACT
Extract part of a date
FROM_DAYS()
Convert a day number to a date
FROM_UNIXTIME()
Format UNIX timestamp as a date
GET_FORMAT()(v4.1.1)
Return a date format string
HOUR()
Extract the hour
LAST_DAY(v4.1.1)
Return the last day of the month for the argument
LOCALTIME(), LOCALTIME
Synonym for NOW()
LOCALTIMESTAMP, LOCALTIMESTAMP()(v4.0.6)
Synonym for NOW()
MAKEDATE()(v4.1.1)
Create a date from the year and day of year
MAKETIME(v4.1.1)
MAKETIME()
MICROSECOND()(v4.1.1)
Return the microseconds from argument
MINUTE()
Return the minute from the argument
MONTH()
Return the month from the date passed
MONTHNAME()(v4.1.21)
Return the name of the month
NOW()
Return the current date and time
PERIOD_ADD()
Add a period to a year-month
PERIOD_DIFF()
Return the number of months between periods
QUARTER()
Return the quarter from a date argument
SEC_TO_TIME()
Converts seconds to 'HH:MM:SS' format
SECOND()
Return the second (0-59)
STR_TO_DATE()(v4.1.1)
Convert a string to a date
SUBDATE()
When invoked with three arguments a synonym for DATE_SUB()
SUBTIME()(v4.1.1)
Subtract times
SYSDATE()
Return the time at which the function executes
TIME_FORMAT()
Format as time
TIME_TO_SEC()
Return the argument converted to seconds
TIME()(v4.1.1)
Extract the time portion of the expression passed
TIMEDIFF()(v4.1.1)
Subtract time
TIMESTAMP()(v4.1.1)
With a single argument, this function returns the date or datetime expression. With two arguments, the sum of the arguments
TO_DAYS()
Return the date argument converted to days
UNIX_TIMESTAMP()
Return a UNIX timestamp
UTC_DATE()(v4.1.1)
Return the current UTC date
UTC_TIME()(v4.1.1)
Return the current UTC time
UTC_TIMESTAMP()(v4.1.1)
Return the current UTC date and time
WEEK()
Return the week number
WEEKDAY()
Return the weekday index
WEEKOFYEAR()(v4.1.1)
Return the calendar week of the date (1-53)
YEAR()
Return the year
YEARWEEK()
Return the year and week
Here is an example that uses date functions. The following query selects all rows with a date_col value from within the last 30 days:
mysql> SELECT something FROM tbl_name
-> WHERE DATE_SUB(CURDATE(),INTERVAL 30 DAY) <= date_col;
Note that the query also selects rows with dates that lie in the future.
Functions that expect date values usually accept datetime values and ignore the time part. Functions that expect time values usually accept datetime values and ignore the date part.
Functions that return the current date or time each are evaluated only once per query at the start of query execution. This means that multiple references to a function such as NOW() within a single query always produce the same result. This principle also applies to CURDATE(), CURTIME(), UTC_DATE(), UTC_TIME(), UTC_TIMESTAMP(), and to any of their synonyms.
Beginning with MySQL 4.1.3, the CURRENT_TIMESTAMP(), CURRENT_TIME(), CURRENT_DATE(), and FROM_UNIXTIME() functions return values in the connection's current time zone, which is available as the value of the time_zone system variable. In addition, UNIX_TIMESTAMP() assumes that its argument is a datetime value in the current time zone. See Section 9.7, “MySQL Server Time Zone Support”.
Some date functions can be used with “zero” dates or incomplete dates such as '2001-11-00', whereas others cannot. Functions that extract parts of dates typically work with incomplete dates. For example:
mysql> SELECT DAYOFMONTH('2001-11-00'), MONTH('2005-00-00');
-> 0, 0
Other functions expect complete dates and return NULL for incomplete dates. These include functions that perform date arithmetic or that map parts of dates to names. For example:
mysql> SELECT DATE_ADD('2006-05-00',INTERVAL 1 DAY);
-> NULL
mysql> SELECT DAYNAME('2006-05-00');
-> NULL
• ADDDATE(date,INTERVAL expr unit), ADDDATE(expr,days)
When invoked with the INTERVAL form of the second argument, ADDDATE() is a synonym for DATE_ADD(). The related function SUBDATE() is a synonym for DATE_SUB(). For information on the INTERVAL unit argument, see the discussion for DATE_ADD().
mysql> SELECT DATE_ADD('1998-01-02', INTERVAL 31 DAY);
-> '1998-02-02'
mysql> SELECT ADDDATE('1998-01-02', INTERVAL 31 DAY);
-> '1998-02-02'
As of MySQL 4.1.1, the second syntax is allowed. When invoked with the days form of the second argument, MySQL treats it as an integer number of days to be added to expr.
mysql> SELECT ADDDATE('1998-01-02', 31);
-> '1998-02-02'
• ADDTIME(expr1,expr2)
ADDTIME() adds expr2 to expr1 and returns the result. expr1 is a time or datetime expression, and expr2 is a time expression.
mysql> SELECT ADDTIME('2007-12-31 23:59:59.999999',
-> '1 1:1:1.000002');
-> '2008-01-02 01:01:01.000001'
mysql> SELECT ADDTIME('01:00:00.999999', '02:00:00.999998');
-> '03:00:01.999997'
ADDTIME() was added in MySQL 4.1.1.
• CONVERT_TZ(dt,from_tz,to_tz)
CONVERT_TZ() converts a datetime value dt from the time zone given by from_tz to the time zone given by to_tz and returns the resulting value. Time zones are specified as described in Section 9.7, “MySQL Server Time Zone Support”. This function returns NULL if the arguments are invalid.
If the value falls out of the supported range of the TIMESTAMP type when converted from from_tz to UTC, no conversion occurs. The TIMESTAMP range is described in Section 10.1.2, “Overview of Date and Time Types”.
mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','GMT','MET');
-> '2004-01-01 13:00:00'
mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','+00:00','+10:00');
-> '2004-01-01 22:00:00'
Note
To use named time zones such as 'MET' or 'Europe/Moscow', the time zone tables must be properly set up. See Section 9.7, “MySQL Server Time Zone Support”, for instructions.
CONVERT_TZ() was added in MySQL 4.1.3.
If you intend to use CONVERT_TZ() while other tables are locked with LOCK TABLES, you must also lock the mysql.time_zone_name table.
• CURDATE()
Returns the current date as a value in 'YYYY-MM-DD' or YYYYMMDD format, depending on whether the function is used in a string or numeric context.
mysql> SELECT CURDATE();
-> '2008-06-13'
mysql> SELECT CURDATE() + 0;
-> 20080613
• CURRENT_DATE, CURRENT_DATE()
CURRENT_DATE and CURRENT_DATE() are synonyms for CURDATE().
• CURTIME()
Returns the current time as a value in 'HH:MM:SS' or HHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. (There is no .uuuuuu part before MySQL 4.1.13.) The value is expressed in the current time zone.
mysql> SELECT CURTIME();
-> '23:50:26'
mysql> SELECT CURTIME() + 0;
-> 235026.000000
• CURRENT_TIME, CURRENT_TIME()
CURRENT_TIME and CURRENT_TIME() are synonyms for CURTIME().
• CURRENT_TIMESTAMP, CURRENT_TIMESTAMP()
CURRENT_TIMESTAMP and CURRENT_TIMESTAMP() are synonyms for NOW().
• DATE(expr)
Extracts the date part of the date or datetime expression expr.
mysql> SELECT DATE('2003-12-31 01:02:03');
-> '2003-12-31'
DATE() is available as of MySQL 4.1.1.
• DATEDIFF(expr1,expr2)
DATEDIFF() returns expr1 – expr2 expressed as a value in days from one date to the other. expr1 and expr2 are date or date-and-time expressions. Only the date parts of the values are used in the calculation.
mysql> SELECT DATEDIFF('2007-12-31 23:59:59','2007-12-30');
-> 1
mysql> SELECT DATEDIFF('2010-11-30 23:59:59','2010-12-31');
-> -31
DATEDIFF() was added in MySQL 4.1.1.
• DATE_ADD(date,INTERVAL expr unit), DATE_SUB(date,INTERVAL expr unit)
These functions perform date arithmetic. The date argument specifies the starting date or datetime value. expr is an expression specifying the interval value to be added or subtracted from the starting date. expr is a string; it may start with a “-” for negative intervals. unit is a keyword indicating the units in which the expression should be interpreted.
The INTERVAL keyword and the unit specifier are not case sensitive.
The following table shows the expected form of the expr argument for each unit value.
unit Value Expected expr Format Version
MICROSECOND MICROSECONDS 4.1.1
SECOND SECONDS Pre-4.1
MINUTE MINUTES Pre-4.1
HOUR HOURS Pre-4.1
DAY DAYS Pre-4.1
WEEK WEEKS 5.0.0
MONTH MONTHS Pre-4.1
QUARTER QUARTERS 5.0.0
YEAR YEARS Pre-4.1
SECOND_MICROSECOND 'SECONDS.MICROSECONDS' 4.1.1
MINUTE_MICROSECOND 'MINUTES.MICROSECONDS' 4.1.1
MINUTE_SECOND 'MINUTES:SECONDS' 4.1.1
HOUR_MICROSECOND 'HOURS.MICROSECONDS' 4.1.1
HOUR_SECOND 'HOURS:MINUTES:SECONDS' 4.1.1
HOUR_MINUTE 'HOURS:MINUTES' Pre-4.1
DAY_MICROSECOND 'DAYS.MICROSECONDS' 4.1.1
DAY_SECOND 'DAYS HOURS:MINUTES:SECONDS' Pre-4.1
DAY_MINUTE 'DAYS HOURS:MINUTES' Pre-4.1
DAY_HOUR 'DAYS HOURS' Pre-4.1
YEAR_MONTH 'YEARS-MONTHS' Pre-4.1
The type values DAY_MICROSECOND, HOUR_MICROSECOND, MINUTE_MICROSECOND, SECOND_MICROSECOND, and MICROSECOND are allowed as of MySQL 4.1.1.
MySQL allows any punctuation delimiter in the expr format. Those shown in the table are the suggested delimiters. If the date argument is a DATE value and your calculations involve only YEAR, MONTH, and DAY parts (that is, no time parts), the result is a DATE value. Otherwise, the result is a DATETIME value.
As of MySQL 3.23, date arithmetic also can be performed using INTERVAL together with the + or - operator:
date + INTERVAL expr unit
date - INTERVAL expr unit
INTERVAL expr unit is allowed on either side of the + operator if the expression on the other side is a date or datetime value. For the - operator, INTERVAL expr unit is allowed only on the right side, because it makes no sense to subtract a date or datetime value from an interval.
mysql> SELECT '2008-12-31 23:59:59' + INTERVAL 1 SECOND;
-> '2009-01-01 00:00:00'
mysql> SELECT INTERVAL 1 DAY + '2008-12-31';
-> '2009-01-01'
mysql> SELECT '2005-01-01' - INTERVAL 1 SECOND;
-> '2004-12-31 23:59:59'
mysql> SELECT DATE_ADD('2000-12-31 23:59:59',
-> INTERVAL 1 SECOND);
-> '2001-01-01 00:00:00'
mysql> SELECT DATE_ADD('2010-12-31 23:59:59',
-> INTERVAL 1 DAY);
-> '2011-01-01 23:59:59'
mysql> SELECT DATE_ADD('2100-12-31 23:59:59',
-> INTERVAL '1:1' MINUTE_SECOND);
-> '2101-01-01 00:01:00'
mysql> SELECT DATE_SUB('2005-01-01 00:00:00',
-> INTERVAL '1 1:1:1' DAY_SECOND);
-> '2004-12-30 22:58:59'
mysql> SELECT DATE_ADD('1900-01-01 00:00:00',
-> INTERVAL '-1 10' DAY_HOUR);
-> '1899-12-30 14:00:00'
mysql> SELECT DATE_SUB('1998-01-02', INTERVAL 31 DAY);
-> '1997-12-02'
mysql> SELECT DATE_ADD('1992-12-31 23:59:59.000002',
-> INTERVAL '1.999999' SECOND_MICROSECOND);
-> '1993-01-01 00:00:01.000001'
If you specify an interval value that is too short (does not include all the interval parts that would be expected from the unit keyword), MySQL assumes that you have left out the leftmost parts of the interval value. For example, if you specify a unit of DAY_SECOND, the value of expr is expected to have days, hours, minutes, and seconds parts. If you specify a value like '1:10', MySQL assumes that the days and hours parts are missing and the value represents minutes and seconds. In other words, '1:10' DAY_SECOND is interpreted in such a way that it is equivalent to '1:10' MINUTE_SECOND. This is analogous to the way that MySQL interprets TIME values as representing elapsed time rather than as a time of day.
Because expr is treated as a string, be careful if you specify a non-string value with INTERVAL. For example, with an interval specifier of HOUR_MINUTE, 6/4 evaluates to 1.50 and is treated as 1 hour, 50 minutes:
mysql> SELECT 6/4;
-> 1.50
mysql> SELECT DATE_ADD('1999-01-01', INTERVAL 6/4 HOUR_MINUTE);
-> '1999-01-01 01:50:00'
If you add to or subtract from a date value something that contains a time part, the result is automatically converted to a datetime value:
mysql> SELECT DATE_ADD('1999-01-01', INTERVAL 1 DAY);
-> '1999-01-02'
mysql> SELECT DATE_ADD('1999-01-01', INTERVAL 1 HOUR);
-> '1999-01-01 01:00:00'
If you add MONTH, YEAR_MONTH, or YEAR and the resulting date has a day that is larger than the maximum day for the new month, the day is adjusted to the maximum days in the new month:
mysql> SELECT DATE_ADD('1998-01-30', INTERVAL 1 MONTH);
-> '1998-02-28'
Date arithmetic operations require complete dates and do not work with incomplete dates such as '2006-07-00' or badly malformed dates:
mysql> SELECT DATE_ADD('2006-07-00', INTERVAL 1 DAY);
-> NULL
mysql> SELECT '2005-03-32' + INTERVAL 1 MONTH;
-> NULL
• DATE_FORMAT(date,format)
Formats the date value according to the format string.
The following specifiers may be used in the format string. As of MySQL 3.23, the “%” character is required before format specifier characters. In earlier versions of MySQL, “%” was optional.
Specifier Description
%a Abbreviated weekday name (Sun..Sat)
%b Abbreviated month name (Jan..Dec)
%c Month, numeric (0..12)
%D Day of the month with English suffix (0th, 1st, 2nd, 3rd, …)
%d Day of the month, numeric (00..31)
%e Day of the month, numeric (0..31)
%f Microseconds (000000..999999)
%H Hour (00..23)
%h Hour (01..12)
%I Hour (01..12)
%i Minutes, numeric (00..59)
%j Day of year (001..366)
%k Hour (0..23)
%l Hour (1..12)
%M Month name (January..December)
%m Month, numeric (00..12)
%p AM or PM
%r Time, 12-hour (hh:mm:ss followed by AM or PM)
%S Seconds (00..59)
%s Seconds (00..59)
%T Time, 24-hour (hh:mm:ss)
%U Week (00..53), where Sunday is the first day of the week
%u Week (00..53), where Monday is the first day of the week
%V Week (01..53), where Sunday is the first day of the week; used with %X
%v Week (01..53), where Monday is the first day of the week; used with %x
%W Weekday name (Sunday..Saturday)
%w Day of the week (0=Sunday..6=Saturday)
%X Year for the week where Sunday is the first day of the week, numeric, four digits; used with %V
%x Year for the week, where Monday is the first day of the week, numeric, four digits; used with %v
%Y Year, numeric, four digits
%y Year, numeric (two digits)
%% A literal “%” character
%x x, for any “x” not listed above
The %v, %V, %x, and %X format specifiers are available as of MySQL 3.23.8. %f is available as of MySQL 4.1.1.
Ranges for the month and day specifiers begin with zero due to the fact that MySQL allows the storing of incomplete dates such as '2004-00-00' (as of MySQL 3.23).
As of MySQL 4.1.21, the language used for day and month names and abbreviations is controlled by the value of the lc_time_names system variable (Section 9.8, “MySQL Server Locale Support”).
As of MySQL 4.1.23, DATE_FORMAT() returns a string with a character set and collation given by character_set_connection and collation_connection so that it can return month and weekday names containing non-ASCII characters. Before 4.1.23, the return value is a binary string.
mysql> SELECT DATE_FORMAT('2009-10-04 22:23:00', '%W %M %Y');
-> 'Sunday October 2009'
mysql> SELECT DATE_FORMAT('2007-10-04 22:23:00', '%H:%i:%s');
-> '22:23:00'
mysql> SELECT DATE_FORMAT('1900-10-04 22:23:00',
-> '%D %y %a %d %m %b %j');
-> '4th 00 Thu 04 10 Oct 277'
mysql> SELECT DATE_FORMAT('1997-10-04 22:23:00',
-> '%H %k %I %r %T %S %w');
-> '22 22 10 10:23:00 PM 22:23:00 00 6'
mysql> SELECT DATE_FORMAT('1999-01-01', '%X %V');
-> '1998 52'
mysql> SELECT DATE_FORMAT('2006-06-00', '%d');
-> '00'
• DATE_SUB(date,INTERVAL expr unit)
See the description for DATE_ADD().
• DAY(date)
DAY() is a synonym for DAYOFMONTH(). It is available as of MySQL 4.1.1.
• DAYNAME(date)
Returns the name of the weekday for date. As of MySQL 4.1.21, the language used for the name is controlled by the value of the lc_time_names system variable (Section 9.8, “MySQL Server Locale Support”).
mysql> SELECT DAYNAME('1998-02-05');
-> 'Thursday'
• DAYOFMONTH(date)
Returns the day of the month for date, in the range 1 to 31, or 0 for dates such as '0000-00-00' or '2008-00-00' that have a zero day part.
mysql> SELECT DAYOFMONTH('1998-02-03');
-> 3
• DAYOFWEEK(date)
Returns the weekday index for date (1 = Sunday, 2 = Monday, …, 7 = Saturday). These index values correspond to the ODBC standard.
mysql> SELECT DAYOFWEEK('1998-02-03');
-> 3
• DAYOFYEAR(date)
Returns the day of the year for date, in the range 1 to 366.
mysql> SELECT DAYOFYEAR('1998-02-03');
-> 34
• EXTRACT(unit FROM date)
The EXTRACT() function uses the same kinds of unit specifiers as DATE_ADD() or DATE_SUB(), but extracts parts from the date rather than performing date arithmetic.
mysql> SELECT EXTRACT(YEAR FROM '1999-07-02');
-> 1999
mysql> SELECT EXTRACT(YEAR_MONTH FROM '1999-07-02 01:02:03');
-> 199907
mysql> SELECT EXTRACT(DAY_MINUTE FROM '1999-07-02 01:02:03');
-> 20102
mysql> SELECT EXTRACT(MICROSECOND
-> FROM '2003-01-02 10:30:00.000123');
-> 123
EXTRACT() was added in MySQL 3.23.0.
• FROM_DAYS(N)
Given a day number N, returns a DATE value.
mysql> SELECT FROM_DAYS(730669);
-> '2007-07-03'
Use FROM_DAYS() with caution on old dates. It is not intended for use with values that precede the advent of the Gregorian calendar (1582). See Section 11.7, “What Calendar Is Used By MySQL?”.
• FROM_UNIXTIME(unix_timestamp), FROM_UNIXTIME(unix_timestamp,format)
Returns a representation of the unix_timestamp argument as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. (There is no .uuuuuu part before MySQL 4.1.13.) The value is expressed in the current time zone. unix_timestamp is an internal timestamp value such as is produced by the UNIX_TIMESTAMP() function.
If format is given, the result is formatted according to the format string, which is used the same way as listed in the entry for the DATE_FORMAT() function.
mysql> SELECT FROM_UNIXTIME(1196440219);
-> '2007-11-30 10:30:19'
mysql> SELECT FROM_UNIXTIME(1196440219) + 0;
-> 20071130103019.000000
mysql> SELECT FROM_UNIXTIME(UNIX_TIMESTAMP(),
-> '%Y %D %M %h:%i:%s %x');
-> '2007 30th November 10:30:59 2007'
Note: If you use UNIX_TIMESTAMP() and FROM_UNIXTIME() to convert between TIMESTAMP values and Unix timestamp values, the conversion is lossy because the mapping is not one-to-one in both directions. For details, see the description of the UNIX_TIMESTAMP() function.
• GET_FORMAT(DATE|TIME|DATETIME, 'EUR'|'USA'|'JIS'|'ISO'|'INTERNAL')
Returns a format string. This function is useful in combination with the DATE_FORMAT() and the STR_TO_DATE() functions.
The possible values for the first and second arguments result in several possible format strings (for the specifiers used, see the table in the DATE_FORMAT() function description). ISO format refers to ISO 9075, not ISO 8601.
Function Call Result
GET_FORMAT(DATE,'USA')
'%m.%d.%Y'
GET_FORMAT(DATE,'JIS')
'%Y-%m-%d'
GET_FORMAT(DATE,'ISO')
'%Y-%m-%d'
GET_FORMAT(DATE,'EUR')
'%d.%m.%Y'
GET_FORMAT(DATE,'INTERNAL')
'%Y%m%d'
GET_FORMAT(DATETIME,'USA')
'%Y-%m-%d %H.%i.%s'
GET_FORMAT(DATETIME,'JIS')
'%Y-%m-%d %H:%i:%s'
GET_FORMAT(DATETIME,'ISO')
'%Y-%m-%d %H:%i:%s'
GET_FORMAT(DATETIME,'EUR')
'%Y-%m-%d %H.%i.%s'
GET_FORMAT(DATETIME,'INTERNAL')
'%Y%m%d%H%i%s'
GET_FORMAT(TIME,'USA')
'%h:%i:%s %p'
GET_FORMAT(TIME,'JIS')
'%H:%i:%s'
GET_FORMAT(TIME,'ISO')
'%H:%i:%s'
GET_FORMAT(TIME,'EUR')
'%H.%i.%s'
GET_FORMAT(TIME,'INTERNAL')
'%H%i%s'
As of MySQL 4.1.4, TIMESTAMP can also be used as the first argument to GET_FORMAT(), in which case the function returns the same values as for DATETIME.
mysql> SELECT DATE_FORMAT('2003-10-03',GET_FORMAT(DATE,'EUR'));
-> '03.10.2003'
mysql> SELECT STR_TO_DATE('10.31.2003',GET_FORMAT(DATE,'USA'));
-> '2003-10-31'
GET_FORMAT() is available as of MySQL 4.1.1.
• HOUR(time)
Returns the hour for time. The range of the return value is 0 to 23 for time-of-day values. However, the range of TIME values actually is much larger, so HOUR can return values greater than 23.
mysql> SELECT HOUR('10:05:03');
-> 10
mysql> SELECT HOUR('272:59:59');
-> 272
• LAST_DAY(date)
Takes a date or datetime value and returns the corresponding value for the last day of the month. Returns NULL if the argument is invalid.
mysql> SELECT LAST_DAY('2003-02-05');
-> '2003-02-28'
mysql> SELECT LAST_DAY('2004-02-05');
-> '2004-02-29'
mysql> SELECT LAST_DAY('2004-01-01 01:01:01');
-> '2004-01-31'
mysql> SELECT LAST_DAY('2003-03-32');
-> NULL
LAST_DAY() is available as of MySQL 4.1.1.
• LOCALTIME, LOCALTIME()
LOCALTIME and LOCALTIME() are synonyms for NOW().
• LOCALTIMESTAMP, LOCALTIMESTAMP()
LOCALTIMESTAMP and LOCALTIMESTAMP() are synonyms for NOW().
They were added in MySQL 4.0.6.
• MAKEDATE(year,dayofyear)
Returns a date, given year and day-of-year values. dayofyear must be greater than 0 or the result is NULL.
mysql> SELECT MAKEDATE(2001,31), MAKEDATE(2001,32);
-> '2001-01-31', '2001-02-01'
mysql> SELECT MAKEDATE(2001,365), MAKEDATE(2004,365);
-> '2001-12-31', '2004-12-30'
mysql> SELECT MAKEDATE(2001,0);
-> NULL
MAKEDATE() is available as of MySQL 4.1.1.
• MAKETIME(hour,minute,second)
Returns a time value calculated from the hour, minute, and second arguments.
mysql> SELECT MAKETIME(12,15,30);
-> '12:15:30'
MAKETIME() is available as of MySQL 4.1.1.
• MICROSECOND(expr)
Returns the microseconds from the time or datetime expression expr as a number in the range from 0 to 999999.
mysql> SELECT MICROSECOND('12:00:00.123456');
-> 123456
mysql> SELECT MICROSECOND('2009-12-31 23:59:59.000010');
-> 10
MICROSECOND() is available as of MySQL 4.1.1.
• MINUTE(time)
Returns the minute for time, in the range 0 to 59.
mysql> SELECT MINUTE('98-02-03 10:05:03');
-> 5
• MONTH(date)
Returns the month for date, in the range 1 to 12 for January to December, or 0 for dates such as '0000-00-00' or '2008-00-00' that have a zero month part.
mysql> SELECT MONTH('1998-02-03');
-> 2
• MONTHNAME(date)
Returns the full name of the month for date. As of MySQL 4.1.21, the language used for the name is controlled by the value of the lc_time_names system variable (Section 9.8, “MySQL Server Locale Support”).
mysql> SELECT MONTHNAME('1998-02-05');
-> 'February'
• NOW()
Returns the current date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. (There is no .uuuuuu part before MySQL 4.1.13.) The value is expressed in the current time zone.
mysql> SELECT NOW();
-> '2007-12-15 23:50:26'
mysql> SELECT NOW() + 0;
-> 20071215235026.000000
• PERIOD_ADD(P,N)
Adds N months to period P (in the format YYMM or YYYYMM). Returns a value in the format YYYYMM. Note that the period argument P is not a date value.
mysql> SELECT PERIOD_ADD(9801,2);
-> 199803
• PERIOD_DIFF(P1,P2)
Returns the number of months between periods P1 and P2. P1 and P2 should be in the format YYMM or YYYYMM. Note that the period arguments P1 and P2 are not date values.
mysql> SELECT PERIOD_DIFF(9802,199703);
-> 11
• QUARTER(date)
Returns the quarter of the year for date, in the range 1 to 4.
mysql> SELECT QUARTER('98-04-01');
-> 2
• SECOND(time)
Returns the second for time, in the range 0 to 59.
mysql> SELECT SECOND('10:05:03');
-> 3
• SEC_TO_TIME(seconds)
Returns the seconds argument, converted to hours, minutes, and seconds, as a TIME value. The range of the result is constrained to that of the TIME data type. A warning occurs if the argument corresponds to a value outside that range.
mysql> SELECT SEC_TO_TIME(2378);
-> '00:39:38'
mysql> SELECT SEC_TO_TIME(2378) + 0;
-> 3938
Note
You cannot use format "%X%V" to convert a year-week string to a date because the combination of a year and week does not uniquely identify a year and month if the week crosses a month boundary. To convert a year-week to a date, then you should also specify the weekday:
mysql> SELECT STR_TO_DATE('200442 Monday', '%X%V %W');
-> '2004-10-18'
• STR_TO_DATE(str,format)
This is the inverse of the DATE_FORMAT() function. It takes a string str and a format string format. STR_TO_DATE() returns a DATETIME value if the format string contains both date and time parts, or a DATE or TIME value if the string contains only date or time parts.
The date, time, or datetime values contained in str should be given in the format indicated by format. For the specifiers that can be used in format, see the DATE_FORMAT() function description. If str contains an illegal date, time, or datetime value, STR_TO_DATE() returns NULL.
Range checking on the parts of date values is as described in Section 10.3.1, “The DATETIME, DATE, and TIMESTAMP Types”. This means, for example, that a date with a day part larger than the number of days in a month is allowable as long as the day part is in the range from 1 to 31. Also, “zero” dates or dates with part values of 0 are allowed.
mysql> SELECT STR_TO_DATE('00/00/0000', '%m/%d/%Y');
-> '0000-00-00'
mysql> SELECT STR_TO_DATE('04/31/2004', '%m/%d/%Y');
-> '2004-04-31'
STR_TO_DATE() is available as of MySQL 4.1.1.
• SUBDATE(date,INTERVAL expr unit), SUBDATE(expr,days)
When invoked with the INTERVAL form of the second argument, SUBDATE() is a synonym for DATE_SUB(). For information on the INTERVAL unit argument, see the discussion for DATE_ADD().
mysql> SELECT DATE_SUB('2008-01-02', INTERVAL 31 DAY);
-> '2007-12-02'
mysql> SELECT SUBDATE('2008-01-02', INTERVAL 31 DAY);
-> '2007-12-02'
As of MySQL 4.1.1, the second syntax is allowed, where expr is a date or datetime expression and days is the number of days to be subtracted from expr.
mysql> SELECT SUBDATE('2008-01-02 12:00:00', 31);
-> '2007-12-02 12:00:00'
• SUBTIME(expr1,expr2)
SUBTIME() returns expr1 – expr2 expressed as a value in the same format as expr1. expr1 is a time or datetime expression, and expr2 is a time expression.
mysql> SELECT SUBTIME('2007-12-31 23:59:59.999999','1 1:1:1.000002');
-> '2007-12-30 22:58:58.999997'
mysql> SELECT SUBTIME('01:00:00.999999', '02:00:00.999998');
-> '-00:59:59.999999'
SUBTIME() was added in MySQL 4.1.1.
• SYSDATE()
Returns the current date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. (There is no .uuuuuu part before MySQL 4.1.13.)
• TIME(expr)
Extracts the time part of the time or datetime expression expr and returns it as a string.
mysql> SELECT TIME('2003-12-31 01:02:03');
-> '01:02:03'
mysql> SELECT TIME('2003-12-31 01:02:03.000123');
-> '01:02:03.000123'
TIME() is available as of MySQL 4.1.1.
• TIMEDIFF(expr1,expr2)
TIMEDIFF() returns expr1 – expr2 expressed as a time value. expr1 and expr2 are time or date-and-time expressions, but both must be of the same type.
mysql> SELECT TIMEDIFF('2000:01:01 00:00:00',
-> '2000:01:01 00:00:00.000001');
-> '-00:00:00.000001'
mysql> SELECT TIMEDIFF('2008-12-31 23:59:59.000001',
-> '2008-12-30 01:01:01.000002');
-> '46:58:57.999999'
TIMEDIFF() was added in MySQL 4.1.1.
• TIMESTAMP(expr), TIMESTAMP(expr1,expr2)
With a single argument, this function returns the date or datetime expression expr as a datetime value. With two arguments, it adds the time expression expr2 to the date or datetime expression expr1 and returns the result as a datetime value.
mysql> SELECT TIMESTAMP('2003-12-31');
-> '2003-12-31 00:00:00'
mysql> SELECT TIMESTAMP('2003-12-31 12:00:00','12:00:00');
-> '2004-01-01 00:00:00'
TIMESTAMP() is available as of MySQL 4.1.1.
• TIME_FORMAT(time,format)
This is used like the DATE_FORMAT() function, but the format string may contain format specifiers only for hours, minutes, and seconds. Other specifiers produce a NULL value or 0.
If the time value contains an hour part that is greater than 23, the %H and %k hour format specifiers produce a value larger than the usual range of 0..23. The other hour format specifiers produce the hour value modulo 12.
mysql> SELECT TIME_FORMAT('100:00:00', '%H %k %h %I %l');
-> '100 100 04 04 4'
• TIME_TO_SEC(time)
Returns the time argument, converted to seconds.
mysql> SELECT TIME_TO_SEC('22:23:00');
-> 80580
mysql> SELECT TIME_TO_SEC('00:39:38');
-> 2378
• TO_DAYS(date)
Given a date date, returns a day number (the number of days since year 0).
mysql> SELECT TO_DAYS(950501);
-> 728779
mysql> SELECT TO_DAYS('2007-10-07');
-> 733321
TO_DAYS() is not intended for use with values that precede the advent of the Gregorian calendar (1582), because it does not take into account the days that were lost when the calendar was changed. For dates before 1582 (and possibly a later year in other locales), results from this function are not reliable. See Section 11.7, “What Calendar Is Used By MySQL?”, for details.
Remember that MySQL converts two-digit year values in dates to four-digit form using the rules in Section 10.3, “Date and Time Types”. For example, '1997-10-07' and '97-10-07' are seen as identical dates:
mysql> SELECT TO_DAYS('1997-10-07'), TO_DAYS('97-10-07');
-> 729669, 729669
• UNIX_TIMESTAMP(), UNIX_TIMESTAMP(date)
If called with no argument, returns a Unix timestamp (seconds since '1970-01-01 00:00:00' UTC) as an unsigned integer. If UNIX_TIMESTAMP() is called with a date argument, it returns the value of the argument as seconds since '1970-01-01 00:00:00' UTC. date may be a DATE string, a DATETIME string, a TIMESTAMP, or a number in the format YYMMDD or YYYYMMDD. The server interprets date as a value in the current time zone and converts it to an internal value in UTC. Clients can set their time zone as described in Section 9.7, “MySQL Server Time Zone Support”.
mysql> SELECT UNIX_TIMESTAMP();
-> 1196440210
mysql> SELECT UNIX_TIMESTAMP('2007-11-30 10:30:19');
-> 1196440219
When UNIX_TIMESTAMP() is used on a TIMESTAMP column, the function returns the internal timestamp value directly, with no implicit “string-to-Unix-timestamp” conversion. If you pass an out-of-range date to UNIX_TIMESTAMP(), it returns 0, but please note that only basic range checking is performed (year from 1970 to 2038, month from 01 to 12, day from 01 from 31).
Note: If you use UNIX_TIMESTAMP() and FROM_UNIXTIME() to convert between TIMESTAMP values and Unix timestamp values, the conversion is lossy because the mapping is not one-to-one in both directions. For example, due to conventions for local time zone changes, it is possible for two UNIX_TIMESTAMP() to map two TIMESTAMP values to the same Unix timestamp value. FROM_UNIXTIME() will map that value back to only one of the original TIMESTAMP values. Here is an example, using TIMESTAMP values in the CET time zone:
mysql> SELECT UNIX_TIMESTAMP('2005-03-27 03:00:00');
+---------------------------------------+
| UNIX_TIMESTAMP('2005-03-27 03:00:00') |
+---------------------------------------+
| 1111885200 |
+---------------------------------------+
mysql> SELECT UNIX_TIMESTAMP('2005-03-27 02:00:00');
+---------------------------------------+
| UNIX_TIMESTAMP('2005-03-27 02:00:00') |
+---------------------------------------+
| 1111885200 |
+---------------------------------------+
mysql> SELECT FROM_UNIXTIME(1111885200);
+---------------------------+
| FROM_UNIXTIME(1111885200) |
+---------------------------+
| 2005-03-27 03:00:00 |
+---------------------------+
If you want to subtract UNIX_TIMESTAMP() columns, you might want to cast the result to signed integers. See Section 11.9, “Cast Functions and Operators”.
• UTC_DATE, UTC_DATE()
Returns the current UTC date as a value in 'YYYY-MM-DD' or YYYYMMDD format, depending on whether the function is used in a string or numeric context.
mysql> SELECT UTC_DATE(), UTC_DATE() + 0;
-> '2003-08-14', 20030814
UTC_DATE() is available as of MySQL 4.1.1.
• UTC_TIME, UTC_TIME()
Returns the current UTC time as a value in 'HH:MM:SS' or HHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. (There is no .uuuuuu part before MySQL 4.1.13.)
mysql> SELECT UTC_TIME(), UTC_TIME() + 0;
-> '18:07:53', 180753.000000
UTC_TIME() is available as of MySQL 4.1.1.
• UTC_TIMESTAMP, UTC_TIMESTAMP()
Returns the current UTC date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. (There is no .uuuuuu part before MySQL 4.1.13.)
mysql> SELECT UTC_TIMESTAMP(), UTC_TIMESTAMP() + 0;
-> '2003-08-14 18:08:04', 20030814180804.000000
UTC_TIMESTAMP() is available as of MySQL 4.1.1.
• WEEK(date[,mode])
This function returns the week number for date. The two-argument form of WEEK() allows you to specify whether the week starts on Sunday or Monday and whether the return value should be in the range from 0 to 53 or from 1 to 53. If the mode argument is omitted, the value of the default_week_format system variable is used (or 0 before MySQL 4.0.14). See Section 5.1.3, “System Variables”.
The following table describes how the mode argument works.
First day
Mode of week Range Week 1 is the first week …
0 Sunday 0-53 with a Sunday in this year
1 Monday 0-53 with more than 3 days this year
2 Sunday 1-53 with a Sunday in this year
3 Monday 1-53 with more than 3 days this year
4 Sunday 0-53 with more than 3 days this year
5 Monday 0-53 with a Monday in this year
6 Sunday 1-53 with more than 3 days this year
7 Monday 1-53 with a Monday in this year
A mode value of 3 can be used as of MySQL 4.0.5. Values of 4 and above can be used as of MySQL 4.0.17.
mysql> SELECT WEEK('1998-02-20');
-> 7
mysql> SELECT WEEK('1998-02-20',0);
-> 7
mysql> SELECT WEEK('1998-02-20',1);
-> 8
mysql> SELECT WEEK('1998-12-31',1);
-> 53
Note: In MySQL 4.0, WEEK(date,0) was changed to match the calendar in the USA. Before that, WEEK() was calculated incorrectly for dates in the USA. (In effect, WEEK(date) and WEEK(date,0) were incorrect for all cases.)
Note that if a date falls in the last week of the previous year, MySQL returns 0 if you do not use 2, 3, 6, or 7 as the optional mode argument:
mysql> SELECT YEAR('2000-01-01'), WEEK('2000-01-01',0);
-> 2000, 0
One might argue that MySQL should return 52 for the WEEK() function, because the given date actually occurs in the 52nd week of 1999. We decided to return 0 instead because we want the function to return “the week number in the given year.” This makes use of the WEEK() function reliable when combined with other functions that extract a date part from a date.
If you would prefer the result to be evaluated with respect to the year that contains the first day of the week for the given date, use 0, 2, 5, or 7 as the optional mode argument.
mysql> SELECT WEEK('2000-01-01',2);
-> 52
Alternatively, use the YEARWEEK() function:
mysql> SELECT YEARWEEK('2000-01-01');
-> 199952
mysql> SELECT MID(YEARWEEK('2000-01-01'),5,2);
-> '52'
• WEEKDAY(date)
Returns the weekday index for date (0 = Monday, 1 = Tuesday, … 6 = Sunday).
mysql> SELECT WEEKDAY('2008-02-03 22:23:00');
-> 6
mysql> SELECT WEEKDAY('2007-11-06');
-> 1
• WEEKOFYEAR(date)
Returns the calendar week of the date as a number in the range from 1 to 53. WEEKOFYEAR() is a compatibility function that is equivalent to WEEK(date,3).
mysql> SELECT WEEKOFYEAR('1998-02-20');
-> 8
WEEKOFYEAR() is available as of MySQL 4.1.1.
• YEAR(date)
Returns the year for date, in the range 1000 to 9999, or 0 for the “zero” date.
-> 2008
• YEARWEEK(date), YEARWEEK(date,mode)
Returns year and week for a date. The mode argument works exactly like the mode argument to WEEK(). The year in the result may be different from the year in the date argument for the first and the last week of the year.
mysql> SELECT YEARWEEK('1987-01-01');
-> 198653
Note that the week number is different from what the WEEK() function would return (0) for optional arguments 0 or 1, as WEEK() then returns the week in the context of the given year.
YEARWEEK() was added in MySQL 3.23.8.
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User Comments
Posted by Isaac Shepard on October 11 2003 2:53pm [Delete] [Edit]
If you're looking for generic SQL queries that will allow you to get the days, months, and years between any two given dates, you might consider using these. You just need to substitute date1 and date2 with your date expressions.
NOTE: Some of these formulas are complex because they account for all cases where date1 < date2, date1 = date2, and date1 > date2. Additionally, these formulas can be used in very generic queries where aliases and temporary variables are not allowed.
Number of days between date1 and date2:
TO_DAYS(date2) - TO_DAYS(date1)
Number of months between date1 and date2:
IF((((YEAR(date2) - 1) * 12 + MONTH(date2)) - ((YEAR(date1) - 1) * 12 + MONTH(date1))) > 0, (((YEAR(date2) - 1) * 12 + MONTH(date2)) - ((YEAR(date1) - 1) * 12 + MONTH(date1))) - (MID(date2, 9, 2) < MID(date1, 9, 2)), IF((((YEAR(date2) - 1) * 12 + MONTH(date2)) - ((YEAR(date1) - 1) * 12 + MONTH(date1))) < 0, (((YEAR(date2) - 1) * 12 + MONTH(date2)) - ((YEAR(date1) - 1) * 12 + MONTH(date1))) + (MID(date1, 9, 2) < MID(date2, 9, 2)), (((YEAR(date2) - 1) * 12 + MONTH(date2)) - ((YEAR(date1) - 1) * 12 + MONTH(date1)))))
Number of years between date1 and date2:
IF((YEAR(date2) - YEAR(date1)) > 0, (YEAR(date2) - YEAR(date1)) - (MID(date2, 6, 5) < MID(date1, 6, 5)), IF((YEAR(date2) - YEAR(date1)) < 0, (YEAR(date2) - YEAR(date1)) + (MID(date1, 6, 5) < MID(date2, 6, 5)), (YEAR(date2) - YEAR(date1))))
Now for some comments about these.
1. These results return integer number of years, months, and days. They are "floored." Thus, 1.4 days would display as 1 day, and 13.9 years would display as 13 years. Likewise, -1.4 years would display as -1 year, and -13.9 months would display as -13 months.
2. Note that I use boolean expressions in many cases. Because boolean expressions evaluate to 0 or 1, I can use them to subtract or add 1 from the total based on a condition.
For example, to calculate the number of years between to dates, first simply subtract the years. The problem is that doing so isn't always correct. Consider the number of years between July 1, 1950 and May 1, 1952. Technically, there is only one full year between them. On July 1, 1952 and later, there will be two years. Therefore, you should subtract one year in case the date hasn't yet reached a full year. This is done by checking the if the second month-day is before the first month-
day. If so, this results in a value of 1, which is subtracted from the total. The IF statements are in the formula because we must add one year when dealing with the dates in the opposite order, and we must not add or subtract anything when the difference of the date years is zero.
3. To get the month-day, I use MID. This is better
than using RIGHT, since it will work for both dates
and datetimes.
4. Unlike many other solutions, these queries should
work with dates prior to 01/01/1970.
Posted by Aurelio Sablone on December 6 2002 8:34am [Delete] [Edit]
In order to get the number of seconds between two
datetime values in a table, you could use the
following: SELECT unix_timestamp(date1) -
unix_timestamp(date2) FROM table_name
Posted by [name withheld] on February 6 2003 4:19pm [Delete] [Edit]
Spent some time trying to work out how to calculate the month start x months ago ( so that I can create historical stats on the fly)
here is what I came up with..
((PERIOD_ADD(EXTRACT(YEAR_MONTH FROM CURDATE()),-6)*100)+1)
this gives you the first day of the month six months before the start of the current month in datetime format
Posted by Adam Tylmad on July 28 2003 10:28pm [Delete] [Edit]
To get the date difference between two date-type columns,
use this formula:
sec_to_time(unix_timestamp(EndDateTime) -
unix_timestamp(StartDateTime))
where StartDateTime and EndDateTime are the two columns
/A
Posted by Filip Wolak on August 4 2003 6:44am [Delete] [Edit]
Several times i have come to a followng date/time problem:
In the table i am storing both date and time information in the datetime column. Querying, I want to receive COUNTed results grouped by date, and not date and time. I came to the easy solution:
SELECT DATE_FORMAT(postdate, '%Y-%m-%d') AS dd, COUNT(id) FROM MyTable GROUP BY dd;
I suppose this solution to be quite slow (date formatting).
Later, i 'upgraded' this query to use the string function:
SELECT substring(postdate, 1,10) AS dd, COUNT(id) FROM MyTable GROUP BY dd;
knowing, that the result is in the fixed format. Works faster.
Posted by Stoyan Stefanov on August 16 2003 8:05pm [Delete] [Edit]
Hope this will help somebody. The way I found to sum time:
SELECT SEC_TO_TIME( SUM( TIME_TO_SEC( `time` ) ) ) AS total_time FROM time_table;
Posted by Gerard Manko on December 17 2003 9:27am [Delete] [Edit]
Comparing Dates when using MS Access and MyODBC
If you are using MS Access and have created Access queries to substitute for views (which are not yet available in mySQL), you can use the following syntax ro perform date comparisons and avoid the dreaded "ODBC -- call failed" error:
Select * from [Task Effort Summary]
Where ((Date() + 0) > CLng([Task Effort Summary].[s_end]))
This particular example retuns tasks that are overdue (where todays date is past the scheduled end date). This query was developed for reports on a TUTOS database.
Posted by [name withheld] on January 9 2004 7:59pm [Delete] [Edit]
Note that the built-in default values for the DATE and DATEFIELD column types is out of range. For example, 0000-00-00 is a valid way of expressing NULL, but if the column is set as NOT NULL, 0000-00-00 is still the default value. This can cause problems with some applications using MySQL.
Posted by asdacfd dsfdsf on January 27 2004 3:25am [Delete] [Edit]
I was looking for a function to detect if the current week is odd or even. I could not find one so I use this:
MOD((DATE_FORMAT(CURDATE(),"%v")),2)
The output is a '0'(even) or a '1'(odd)
Posted by Steve West on February 15 2004 10:49pm [Delete] [Edit]
To create a DATETIME of NOW() in UTC without upgrading to 4.1.1, just use:
DATE_ADD( '1970-01-01', INTERVAL UNIX_TIMESTAMP() SECOND )
Posted by [name withheld] on March 4 2004 9:39am [Delete] [Edit]
workaround for STR_TO_DATE pre version 4.1.1. ugly but it seems to work fine.
assumption: you know the format of the received date (in the below example the format is mm/dd/yy, m/d/yy, mm/dd/yyyy, etc)
the statement extracts the year by locating the index of the second '/' and reading from the right of the string to that index. the index of the second is '/' is found by using LOCATE with the index of the first '/'.
it extracts the day by locating the indeces of the first and second '/' and reading between them
it extracts the month by locating the index of the first '/' and reading from the left of the string to that index.
it then CONCATs the year month and day pieces together separating them with hyphens.
lastly, it lets DATE_FORMAT do its magic on the string.
(replace the test string '1/11/03' with your field name, etc)
select DATE_FORMAT( CONCAT( RIGHT( '1/11/03' , length( '1/11/03') - LOCATE('/', '1/11/03' , LOCATE('/', '1/11/03' ) + 1 ) ) , '-' , LEFT( '1/11/03' , LOCATE('/', '1/11/03' ) - 1 ) , '-', SUBSTRING( '1/11/03' , LOCATE('/', '1/11/03' ) + 1, LOCATE('/', '1/11/03' , LOCATE('/', '1/11/03' ) + 1 ) - LOCATE('/', '1/11/03' ) - 1 ) ) , '%Y-%m-%d' )
Posted by Olav Alexander Mjelde on March 15 2004 11:15am [Delete] [Edit]
Lets say you have the mysql before 4.1.1 (where timediff() was implementet), and you want to do a timediff.
I wanted to make a "active users" on my page, but I found out that I didnt have the timediff function (to find persons which have been active within 5 minutes).
So, I figured this query out:
SELECT nick FROM `users` WHERE TO_DAYS( NOW( ) ) - TO_DAYS( last_login ) <=1 AND DATE_FORMAT( CURRENT_TIMESTAMP( ) , '%H%i' ) - DATE_FORMAT( last_login, '%H%i' ) <=5 ORDER BY `nick` ASC;
it selects the field nick (which is the only one to be displayd) and then it filters for 1 day or less in age of activity. after that, it filters for 5 minutes or less in activity.
first you need to filter away the other days, or your script might get fooled to think that yesterdays login was todays.
I'm currently using this, and it works fine!
on the other page, you of course need to update the timestamp field (when session excists, on reload)
Posted by Cherice Scharf on April 5 2004 11:24am [Delete] [Edit]
Here is an example to convert various user inputs for a date field on an ASP page (VBScript) that will convert common formats (i.e., m/d/yy, mm/dd/yyyy, etc.) to MySQL database format of (yyyy-mm-dd). The function begins by establishing that there is a date in the field. Then splits the date (converted to string) into three parts by locating "/". DateArray(0), DateArray(1), DateArray(2) hold the month, day and year, respectively. These are then checked for the amount of digits, if there are not enough digits in month or day then a leading zero is added. If there are only two digits on the year (ie "04") then a leading "20" is added.
Function ConvertInputDate(varDate)
If (Len(Trim(varDate)) > 0) Then
DateArray=Split(CStr(varDate),"/")
IF Len(Trim(DateArray(0))) < 2 Then
DateArray(0) = "0" & DateArray(0)
End If
If Len(Trim(DateArray(1))) < 2 Then
DateArray(1) = "0" & DateArray(1)
End If
If Len(Trim(DateArray(2))) < 4 Then DateArray(2) = "20" & DateArray(2)
End If
varDate = DateArray(2) & "-" & DateArray(0) & "-" & DateArray(1)
End If
End Function
*Please note if a user does not use two slashes this function will not work. It is best to indicate "mm/dd/yy" near the label on the page. It will take 4/6/04, 10/6/04, 3/16/2004 and all combinations with two slashes.
Posted by Jason Richard on April 9 2004 7:20am [Delete] [Edit]
I had a problem with my login script using PHP and MySQL when daylight savings time (DST) came around this year.
I was using MYSQL NOW() function to add the current date and time to the user's record into a datetime field. When DST came into effect newly entered login times were an hour slow (I'm in EST). Since the last login is to be updated only if an hour or more has passed since the last login this was a big problem!
The problem is that PHP takes DST into account and MySQL does not (as far as I know) and I was entering the time using MySQL's NOW() function and then comparing the value returned by PHP's time() function.
A very simple solution to this is the following. Note the PHP time format string 'YmdHis' - it formats to YYYYMMDDHHMMSS which is what MySQL expects for a date/time field.
$now = time();
$lastLogin = strtotime($row['lastLogin']);
$diff = $now - $lastLogin;
$now = date('YmdHis',$now)
if($diff > 3600) { // 3600 seconds is 1 hour
$query = 'UPDATE members SET logins = logins + 1, lastLogin = '.$now.' WHERE memberID = '.$SEC_ID;
mysql_query($query);
}
Now the date entered is the PHP time (that accounts for DST) and we are comparing it to PHP time so all is well.
I think this approach will work well for any time you wish to enter a date into MySQL using PHP. Just format the date using the "YmdHis" format string and use the strtotime() function to read a date retrieved from MySQL.
The advantage to this approach rather than just entering the "normal" PHP date into a char or text field is that the dates are "human" readable in the table and all the MySQL date/time functions are available for future queries.
Posted by Martin Schwedes on April 25 2004 9:11am [Delete] [Edit]
to localize the weekday:
SELECT ELT( WEEKDAY('2004-04-10')+1, 'Montag','Dienstag','Mittwoch','Donnerstag','Freitag','Samstag','Sonntag');
long version with month:
SELECT DATE_FORMAT( '2004-04-10', CONCAT( ELT( WEEKDAY('2004-04-10')+1, 'Montag','Dienstag','Mittwoch','Donnerstag','Freitag','Samstag','Sonntag'),', %d. ', ELT( MONTH('2004-04-10'), 'Januar','Februar','März','April','Mai','Juni','Juli','August','September','Oktober','November','Dezember'),' %Y'));
--> Samstag, 10. April 2004
same for unix-timestamp:
SELECT DATE_FORMAT( FROM_UNIXTIME(1081548000), CONCAT( ELT( WEEKDAY(FROM_UNIXTIME(1081548000))+1, 'Mo','Di','Mi','Do','Fr','Sa','So'),', %d. ', ELT( MONTH(FROM_UNIXTIME(1081548000)), 'Jan.','Feb.','März','April','Mai','Juni','Juli','Aug.','Sept.','Okt.','Nov.','Dez.'),' %Y'));
--> Sa, 10. April 2004
Posted by Philippe Poelvoorde on April 30 2004 5:50am [Delete] [Edit]
I had to query a table and retrieve rows that were added only today, so :
select id from my_table
where
timestamp < date_format(date_add(CURRENT_TIMESTAMP(), interval 1 day),'%Y%m%d000000')
AND
timestamp >= date_format(CURRENT_TIMESTAMP(),'%Y%m%d000000')
starting with MySQL 4.0, you could also use the BETWEEN ... AND syntax.
If anyone has a better query to do that, let me know.
Posted by Michael Marcus on May 1 2004 2:41pm [Delete] [Edit]
After reading numerous articles and posts regarding converting back and forth between SQL datetime and VBscript datetime, I opted for the simplest solution for my databases. I simply save all datetime values in varchar(20) fields and call on either MySQL or VBscript functions to get datetime values or check/convert datetime values. For example:
currentDT = CStr(cn.execute("SELECT NOW()").Fields(0).Value)
will fetch current datetime in the SQL server's datetime format and then convert it to a string. [Obviously, cn is set by Set cn = Server.CreateObject("ADODB.Connection") to create the database connection, then the database is opened with a cn.open (parameters).]
You can then save this string to an appropriate field such as 'flddate_added' which is formatted as varchar(20).
When retrieving the flddate_added value, you can use this VBscript code to check if the value is indeed a datetime value and convert it to the datetime format of the user's computer"
if IsDate(flddate_added) then
=CDate(flddate_added) ' convert to user's system format for display using user's codepage
else
=flddate_added ' just display the string
end if
The above methods allow me to get around all of the issues regarding VBscript's datetime display format differences depending on the system local.
Posted by Ray Morris on July 15 2004 4:37pm [Delete] [Edit]
Posted by Filip Wolak:
> Several times i have come to a followng date/time problem:
> In the table i am storing both date and time information in the datetime
> column. Querying, I want to receive COUNTed results grouped by date,
> and not date and time.
...
> SELECT substring(postdate, 1,10) ...
If it's a DATETIME column than substring is not appropriate -
it's logically nonsensical of course, and just happens to work
in some version of MySQL because the DATETIME happens
to be represented by a string in some contexts.
Better would be to treat the DATETIME as a DATETIME
rather than as a string, which will work in future versions
of MYSQL and in other RDMS:
SELECT DATE(postdate) ...
Posted by David Lyon on July 17 2004 4:12pm [Delete] [Edit]
Here is another VB/ASP function for converting Dates from standard to MySQL format. Cherise gave a nice example above, but it has extra complexity due to the use of arrays and also may be proned to user input errors.
The following example will work based on the Localization settings of the server on which it is run. So it shouldn't care whether the date is dd-mm-yyyy, mm/dd/yy, mm/dd/yyyy, m-d-yy, etc. Just make sure you pass it a date value that is formatted compliant to the server's localization. If necessary use VB's CDate(strDateValue) before passing strDateValue to the function.
You can also easily modify this function to do the same for Time values, except you use Hour, Minute, and Second VB functions, and delimit with a colon (:) instead of a dash (-).
Hope this helps!
Function funcMySqlDate(dtmChangeDate)
'CONVERTS LOCALIZED DATE FORMAT (for example: m/d/yy) TO MySQL FORMAT (yyyy-mm-dd)
Dim strTempYear, strTempMonth, strTempDay
strTempYear = Year(dtmChangeDate)
strTempMonth = Month(dtmChangeDate)
strTempDay = Day(dtmChangeDate)
if Len(strTempYear) = 2 then 'Y2K TEST - 1938-2037 - ADJUST AS NECESSARY
if strTempYear >= 38 then
strTempYear = "19" & strTempYear
else
strTempYear = "20" & strTempYear
end if
end if
if strTempMonth < 10 then strTempMonth = "0" & strTempMonth
if strTempDay < 10 then strTempDay = "0" & strTempDay
funcMySqlDate = strTempYear & "-" & strTempMonth & "-" & strTempDay
End Function
Posted by Benjamin Zagel on August 5 2004 12:44pm [Delete] [Edit]
To find out the last day of a month use:
SELECT (DATE_FORMAT('2004-01-20' ,'%Y-%m-01') - INTERVAL 1 DAY) + INTERVAL 1 MONTH;
It tooks me a few time to have this idea, but it works. If you want to have the first day of a month use:
SELECT DATE_FORMAT('2004-01-20' ,'%Y-%m-01');
To find out the first day of a month was my first development step, then it was easy to extract the last day of a month. It is usefull for accounting for services where I need this solution.
Greetings
Posted by Mark Stafford on August 6 2004 5:26pm [Delete] [Edit]
I see the use for both, but I find this layout more useful as a reference tool:
+--------------+----------+--------------------+
| metric | variant | result |
+--------------+----------+--------------------+
| microseconds | %f | 000000..999999 |
| seconds | %s or %S | 00..59 |
| minutes | %i | 00..59 |
| hours | %H | 00...23 |
| | %h or %I | 00...12 |
| | %k | 0...23 |
| | %l | 1...12 |
| day | %a | Sun...Sat |
| | %D | 1st, 2nd, 3rd |
| | %d | 0.31 |
| | %e | 0..31 |
| | %j | 001...366 |
| | %W | Sunday...Sat |
| | %w | 0...6 |
| week | %U | 00...53 per Sun |
| | %u | 00...53 per Mon |
| * | %V | 01...53 per Sun |
| * | %v | 01...53 per Mon |
| month | %b | Jan...Dec |
| | %c | 0...12 |
| | %M | January...December |
| | %m | 00...12 |
| year | %Y | 1999 |
| | %y | 99 |
| * | %X | 1999 |
| * | %x | 99 |
| time | %r | 01:31:12 pm |
| | | %T | 01:31:12 pm |
| | %p | AM or PM |
| Percent sign | %% | % |
+--------------+----------+--------------------+
Posted by M l on August 7 2004 6:53pm [Delete] [Edit]
Select records that are older than X days from the current date where sent_time is a Timestamp datatype field.
select ID from MESSAGE where SENT_TIME < (CURDATE() - INTERVAL 5 DAY);
Posted by R C on August 24 2004 7:21pm [Delete] [Edit]
If you do not have 4.xx yet here is a simple way to get the last day of the month. You can replace the current date with a var to find the last day of any month.
SELECT
SUBDATE( ADDDATE( CURDATE(), INTERVAL 1 MONTH), INTERVAL DAYOFMONTH( CURDATE() ) DAY) AS LAST_DAY_MONTH
seems to work well .
Posted by John Takacs on September 8 2004 10:39pm [Delete] [Edit]
I'm not sure if this is mentioned above, however, none of the STR_TO_DATE() functions works in MySQL version 4.0.18.
So that there is no misunderstanding, the following SQL copied from the above STR_TO_DATE() section:
SELECT STR_TO_DATE('00/00/0000', '%m/%d/%Y');
returns the following error:
ERROR 1064: You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near '('00/00/0000', '%m/%d/%Y')' at line 1
I copied and pasted all of the examples for STR_TO_DATE and none work.
Posted by Martin Algesten on September 9 2004 2:00pm [Delete] [Edit]
>Several times i have come to a followng date/time problem:
>In the table i am storing both date and time information in the
>datetime column. Querying, I want to receive COUNTed results
>grouped by date, and not date and time. I came to the easy
>solution:
I needed a query for a more general case to do time based reporting on arbitrary big "slices" of timestamped data.
My table has a column 'timestamp' which is of type 'datetime'.
The following makes '120' second big slices
select from_unixtime(unix_timestamp(timestamp) - unix_timestamp(timestamp) % 120) as slice, ... group by slice;
Posted by David Berry on September 17 2004 7:08pm [Delete] [Edit]
I wanted to find the start date (Sunday) and the end date (Saturday) for any given week when all I had to go from is an arbitrary date (more precisely, the current date). Since MySQL registers Sunday as 1, and Saturday as 7, if you wish to adjust the start and end points on a week, you'll have to modify the following function calls appropriately, and change the integers, or (as I have done) use variables:
set @someday = curdate();
set @weekstart = 1; // Sunday
set @weekend = 7; // Saturday
end of week:
select date_add(@someday, interval @weekend-dayofweek(@someday) day);
beginning of week:
select date_sub(@someday, interval dayofweek(@someday)-@weekstart day);
Of course, I use these functions in a more complex query that filters select results from a table with a "datetime" field. This allows me to focus on weekly data. A very neat thing is being able to replace 'curdate()' with a date at (theoretically) any point in time on the Gregorian calendar.
Posted by Jeffrey Friedl on October 31 2004 9:05am [Delete] [Edit]
The value returned by
UNIX_TIMESTAMP(NOW())
can be quite unintuitive during the last hour of daylight-saving time in the fall, as it can return a timestamp that's an hour ahead of the current time. (The docs indicate that this may be "fixed" from 4.1.3, but I have not tested.)
This is because CST-related information is lost during the conversion by NOW() from the current time to a string. When presented a date string like "2004-10-31 01:52:37" which names a time that happened twice (once during daylight-saving time, and again an hour later in standard time), it doesn't know which you intend it to be interpreted as.
The docs indicate that from 4.1.3, it uses the timezone in effect at the time of the SELECT, which implies that
FROM_UNIXTIME("2004-10-31 01:52:37")
returns a different value depending on whether you are currently under daylight-saving time or not. With 4.1.2 and before, it seems to always use standard time, and hence the one-hour "error" (which is not really an error, but damn unintuitive that UNIX_TIMESTAMP(NOW()) does not return the UNIX_TIMESTAMP for now.
Note that UNIX_TIMESTAMP() without args does return the proper unix timestamp for the current time.
Posted by Shamun toha on December 18 2004 10:45am [Delete] [Edit]
If you have a table1 , and (fields date which is varchar(100)
you can also convert it as date type look the following example
mysql> select str_to_date(date,'%d/%m/%Y') as Mydate from table1 order by Mydate DESC;
+------------+
| Mydate |
+------------+
| 2004-12-16 |
| 2004-12-15 |
| 2004-12-02 |
| 2004-12-02 |
| 2004-11-01 |
| 2004-10-29 |
| 2004-10-12 |
| 2004-10-07 |
| 2004-09-12 |
| 2004-08-19 |
| 2004-08-13 |
| 2004-08-09 |
| 2004-08-04 |
| 2004-07-30 |
| 2004-07-26 |
| 2004-07-20 |
| 2004-07-16 |
| 2004-07-14 |
+------------+
18 rows in set (0.00 sec)
mysql>
Posted by John Romano on January 26 2005 10:06pm [Delete] [Edit]
If you need to EXTRACT the QUARTER prior to v5.0 try CEILING(EXTRACT(MONTH FROM date)/3)
Posted by Robert Christiaanse on January 27 2005 2:18pm [Delete] [Edit]
CALCULATING A DATE USING A WEEK NUMBER
If you want to calculate the date having a year, a day of the week and a weeknumber (Let's say Thursday of week number 4 in 2005), you can calculate it like this:
SELECT DATE_ADD('2005-01-04', INTERVAL ((4-1)*7+(4 - DATE_FORMAT('2005-01-04','%w'))) DAY);
In PHP it would be something like this (when weeks start on Monday):
$Days=array('xx','ma','di','wo','do','vr','za','zo');
$DayOfWeek=array_search($aDay,$Days); //get day of week (1=Monday)
$Year=2005;
$Week=4;
$query = "SELECT DATE_ADD('".$Year."-01-04', INTERVAL ((".$Week."-1)*7+(".$DayOfWeek." - DATE_FORMAT('".$Year."-01-04','%w'))) DAY)";
January 4th is chosen as a base, because it is always in week number 1. ( January 1st is not necessarely in week1! )
You can test it with this:
//connect to your database first
$Year=2005;
for ($weeknr=0; $weeknr <= 53; $weeknr++)
{
for ($day=1; $day <= 7; $day++)
{
$query = "
SELECT
DATE_ADD('".$Year."-01-04',
INTERVAL ((".$weeknr."-1)*7+
(".$day." - DATE_FORMAT('".$Year."-01-04','%w'))) DAY)
";
$result= mysql_query($query);
if ($result)
{
$row = mysql_fetch_row($result);
echo "year=$Year weekno=$weeknr day=$day : ".$row[0].'
';
}
else
echo 'empty result set
'.EOL;
}
}
?>
Posted by Ralph Noordanus on February 18 2005 12:23pm [Delete] [Edit]
+---------------------+---------------------+
| date1 | NOW() |
+---------------------+---------------------+
| 2005-03-17 16:00:00 | 2005-02-18 13:07:29 |
+---------------------+---------------------+
If you're looking for an SQL query that returns the number of days, hours and minutes between date1 and now:
SELECT CONCAT(DAYOFYEAR(date1)-DAYOFYEAR(NOW()),' days ', DATE_FORMAT(ADDTIME("2000-00-00 00:00:00",SEC_TO_TIME(TIME_TO_SEC(date1)-TIME_TO_SEC(NOW()))),'%k hours and %i minutes')) AS time FROM time_table;
+---------------------------------+
| time |
+---------------------------------+
| 27 days 2 hours and 52 minutes |
+---------------------------------+
Posted by Luke Burgess on October 15 2006 5:56am [Delete] [Edit]
There doesn't appear to be an official way of selecting * from a table where eg 'date is january 2005'. So far i've found 8 different ways!!
1. where date like '2005-01-%'
2. where DATE_FORMAT(date,'%Y-%m')='2005-01'
3. where EXTRACT(YEAR_MONTH FROM date)='200501'
4. where YEAR(date)='2005' and MONTH(date)='1'
5. where substring(date,1,7)='2005-01'
6. where date between '2005-01-01' and '2005-01-31'
7. where date >= '2005-01-01' and date <= '2005-01-31'
8. where date IN('2005-01-01', '2005-01-02', '2005-01-03', '2005-01-04', '2005-01-05', '2005-01-06', '2005-01-07', '2005-01-08', '2005-01-09', '2005-01-10', '2005-01-11', '2005-01-12', '2005-01-13', '2005-01-14', '2005-01-15', '2005-01-16', '2005-01-17', '2005-01-18', '2005-01-19', '2005-01-20', '2005-01-21', '2005-01-22', '2005-01-23', '2005-01-24', '2005-01-25', '2005-01-26', '2005-01-27', '2005-01-28', '2005-01-29', '2005-01-30', '2005-01-31')
Posted by Josh Hayden on March 20 2005 2:14am [Delete] [Edit]
I needed a query that would delete all rows that were created over an hour ago. Here's what I used:
To insert the row:
INSERT INTO `table_name` ( `time_col`) VALUES (NOW());
To delete the rows created over an hour ago:
DELETE FROM `table_name` WHERE `time_col` < ADDDATE(NOW(), INTERVAL -1HOUR);
Posted by Erin Quick-Laughlin on March 29 2005 12:49am [Delete] [Edit]
To take Cherice Scharf's vb example one step further, here's the conversion from vb's now format of 'MM/DD/YY HH:MM:SS PM' to 'YYYY-MM-DD HH:MM:SS' for easy insertion to the datetime field:
Function ConvertInputDateTime(varDateTime)
If (Len(Trim(varDateTime)) > 0) Then
DateTimeArray=Split(CStr(varDateTime)," ")
varDate = DateTimeArray(0)
varTime = DateTimeArray(1)
varAMPM = DateTimeArray(2)
If (Len(Trim(varDate)) > 0) Then
DateArray=Split(CStr(varDate),"/")
IF Len(Trim(DateArray(0))) < 2 Then
DateArray(0) = "0" & DateArray(0)
End If
If Len(Trim(DateArray(1))) < 2 Then
DateArray(1) = "0" & DateArray(1)
End If
If Len(Trim(DateArray(2))) < 4 Then
DateArray(2) = "20" & DateArray(2)
End If
varDate = DateArray(2) & "-" & DateArray(0) & "-" & DateArray(1)
End If
If (Len(Trim(varDate)) > 0) Then
TimeArray=Split(CStr(varTime),":")
If Trim(varAMPM) = "PM" Then
TimeArray(0) = CStr(TimeArray(0) + 12)
End If
If Len(Trim(TimeArray(0))) < 2 Then
TimeArray(0) = "0" & TimeArray(0)
End If
varTime = TimeArray(0) & ":" & TimeArray(1) & ":" & TimeArray(2)
End If
varDateTime = varDate & " " & varTime
End If
ConvertInputDateTime = varDateTime
End Function
Thanks for the starting code Cherice!
Posted by paul adams on April 1 2005 9:30am [Delete] [Edit]
"SELECT id, transactionid, (UNIX_TIMESTAMP(now()) - UNIX_TIMESTAMP(date)) AS date , sucessful, amount FROM Transaction where sucessful = 1"
to work out the difference between when it was placed to now.
Posted by santi bari on June 10 2005 2:49pm [Delete] [Edit]
GENERATE missing days on a table with date gaps
=====================================
If you want to bring visits per day to your site and you have a table
wich
is storing the hits, in a way similar to this...
+--------------+--------------------------+
| date | IP
+--------------+--------------------------+
|2004-8-3 | 123.123.124.155
|2004-8-3 | 123.123.124.145
|2004-8-5 | 123.123.124.145
+--------------+--------------------------+
You may want to draw a chart and retrieve all the hits per day. The
problem is that DAYS WITHOUT HITS WON'T APPEAR. And you won't be able
to
display the info of '0 hits'.
One solution to this which is easy to code and clean, is to create and
have in your database, a table named 'calendar' with all the days from
today till some years from now (let's say, till 2034). The table
should
look something like this:
+----------+
| date
+----------+
| 2004-1-1
| 2004-1-2
| 2004-1-3
| 2004-1-4
| 2004-1-5
| ...
| etc...
+---------+
Here is a piece of code which will make such table:
mysql_query("CREATE TABLE `calendar` (
`id` int(11) NOT NULL auto_increment,
`date` date NOT NULL default '0000-00-00',
PRIMARY KEY (`id`)
) TYPE=MyISAM; ");
for($i=0;$i<=(365*30);$i++)
mysql_query("INSERT INTO CALENDAR SET date=date_add(now(),INTERVAL
LAST_INSERT_ID() DAY)");
?>
Then all you have to do is perform a LEFT JOIN from this table and
you've
got every day from the period of time you specify. Even those with 0
hits
SELECT calendar.date, count(*)
FROM calendar
LEFT JOIN visits ON calendar.date=visits.date
GROUP BY calendar.date
Posted by Benjamin Gehrels on May 12 2005 1:50am [Delete] [Edit]
Be carefull with the DAYOFYEAR-Function in comparisions, because you will run into a trap every 4 years, when Feburary is a day shorter...
Posted by Labb on May 20 2005 1:24pm [Delete] [Edit]
To Posted by Erin Quick-Laughlin on March 29 2005 2:49am
The much more easier way:
date = "YYYY/MM/DD HH-SS-MM"
date = Replace(date, "/", "-")
thats it...
Posted by Juan Antonio on May 23 2005 3:36pm [Delete] [Edit]
age from date of birth compared whith
in this function you can know the age of a person(it works for my). preg 12 is a date in the format show bellow i dont know if it is fast. if you have a recent version you can asign curtime to a variable for get more performance else use php,c++ or another to save it as:
YYYY-MM-DD example: 1997-03-31
left((curtime()-preg12),(CHAR_LENGTH(curtime()-preg12)-4))
another way is:
(TO_DAYS("a - date") - TO_DAYS("birth"))/365
you can replece the curdate for a before date changing curdate to this 20000619 NOT THIS: 2000-06-19 if you have beter way send it to my tanks bye.
Posted by John Anderson on May 25 2005 8:04pm [Delete] [Edit]
To calculate week ending date given an arbitrary date, use the following (assumes Saturday is week end)
SELECT DATE_ADD('2005-05-24', INTERVAL (7 - DAYOFWEEK('2005-05-24')) DAY)
SELECT DATE_ADD(table.column, INTERVAL (7 - DAYOFWEEK(table.column)) DAY)
Posted by Pe3k on June 15 2005 12:51pm [Delete] [Edit]
If U have older version of MySQL you can replace 'TIMEDIFF(time1,time2)' with
'SEC_TO_TIME( (TO_DAYS(time1)*24*3600+TIME_TO_SEC(time1)) - (TO_DAYS(time2)*24*3600+TIME_TO_SEC(time2)) )'
It is completly same. :)
Posted by Daniel Schroeder on July 16 2005 4:58pm [Delete] [Edit]
I had the task to select rows of a table where the date of creation was in the future of a given date.
The problem was there was no date or timestamp-field, but two fields (int), one for month and one for year.
Since I have MySQL-Version prior to 4.1.1, where most of the nice date/time-functions have been added, I had to work out a query that builds and compares dates out of the given values.
Here it is:
SELECT *
FROM your_table
WHERE CONCAT(your_table.field_year,'-',REPEAT(0,2-LENGTH(your_table.field_month)),your_table.field_month,'-','01') >= CONCAT({MIN_YEAR},'-',REPEAT(0,2-LENGTH({MIN_MONTH})),{MIN_MONTH},'-','01')
ORDER BY your_table.field_year,
your_table.field_month;
I noticed an advantage compared to working with timestamps: You are able to work with dates before 1970.
Posted by Oliver Pereira on July 19 2005 1:40pm [Delete] [Edit]
The description of FROM_DAYS(N) - "Given a daynumber N, returns a DATE value" - uses the term "daynumber" without explaining it.
The description of TO_DAYS(date) - "Given a date date, returns a daynumber (the number of days since year 0)" - lower down the page at least tries to explain the term, but unsuccessfully.
There are two problems here. Firstly, there was no year 0 in the Gregorian calendar. Secondly, a number of days has to be counted from a day, not a year. Do they mean the beginning of the (non-existent) year, or the end of the (non-existent) year? Do non-existent years even have beginnings and ends? Someone should amend these descriptions.
Posted by k s on August 12 2005 7:51am [Delete] [Edit]
Here's another query to get the number of months between two dates:
select period_diff(DATE_FORMAT(date1,'%Y%m'),DATE_FORMAT(date2,'%Y%m')) from tablexy
Posted by Bob Terrell on August 22 2005 5:40pm [Delete] [Edit]
Note that there is currently no way to get the 'AM' or 'PM' part of a time-only value using the built-in functions. You must first convert it to a datetime and then use DATE_FORMAT('%p') or perform your own calculations in your app.
Posted by Deron Meranda on August 31 2005 8:33pm [Delete] [Edit]
On transactional consistency...Concerning the functions which use the real current time, such as NOW(), the manual says "Functions that return the current date or time each are evaluated only once per query at the start of query execution."
Note though that this does not apply across entire transactions, as you may expect. Thus a transaction like:
START TRANSACTION;
INSERT INTO EVENTS VALUES (NOW(), 'A');
INSERT INTO EVENTS VALUES (NOW(), 'B');
COMMIT;
will result in potentially two different times being recorded for the two records.
Posted by cameron green on September 16 2005 6:13am [Delete] [Edit]
If you need the type to be dynamically taken from a table (that is where you have "year", "day", "month" etc as a column in the table), here is the best way I could work out to do it. Expand as necessary :
SELECT set_date, unit_period, unit_multiplier, CASE WHEN unit_period = "month" THEN DATE_SUB(set_date, INTERVAL unit_multiplier MONTH) WHEN unit_period = "week" THEN DATE_SUB(set_date, INTERVAL (unit_multiplier * 7) DAY) WHEN unit_period = "year" THEN DATE_SUB(set_date, INTERVAL unit_multiplier YEAR) ELSE DATE_SUB(set_date, INTERVAL unit_multiplier DAY) END FROM dates_table;
Posted by Andrzej Salamon on September 22 2005 1:27pm [Delete] [Edit]
Returns all rows from actual month to given @months. eg. if you want get all rows in:
5 months from now:
(2005-09) - 5 = (2005-04)
all rows from 2005-04-01 to 2005-04-30
2 months from now
(2005-09) - 2 = (2005-07)
all rows from 2005-07-01 to 2005-07-31
SQL variables, can be PHP variables like $months,$nextMonth,$begin,$end
set @months = 1; #change only this value(months back from actual month)
set @nextMonth = @months+1;
set @begin = FROM_DAYS(TO_DAYS(LAST_DAY( DATE_SUB(NOW(), INTERVAL @nextMonth MONTH )))+1);
set @end = FROM_DAYS(TO_DAYS(LAST_DAY( DATE_SUB(NOW(), INTERVAL @months MONTH )))+1);
SELECT cols_u_want FROM tbl_u_want
WHERE timestampCol
BETWEEN @begin AND @end
It`s my solution. If U have Your own please email me.
Sorry for my english :)
Posted by Bryan Donovan on November 14 2005 9:22pm [Delete] [Edit]
I'm not sure if this is the best way, but it works to get the date of the Monday of the week of a date. For example, if you have a datetime column called starttime in a table called test_events, you could select the distinct Mondays from your table as follows:
SELECT DISTINCT(STR_TO_DATE(CONCAT(YEARWEEK(starttime),'1'),'%x%v%w'))
FROM test_events;
Hopefully there is a better way..
Posted by Rodolfo Maripan on November 29 2005 3:52pm [Delete] [Edit]
I was using mysql v4 and the date was in a varchar data type, in order to change the data type in mysql v5 i use the following code:
update ssd_escondida.tactual_sag4 set ssd_escondida.tactual_sag4.Fecha=str_to_date(ssd_escondida.tactual_sag4.Fecha2,'%e/%m/%Y');
where:
ssd_escondida: database
tactual_sag4:is a table
Fecha: is a date type
Fecha2:is a varchar which contains a date, but is from 01/01/2005 to 04/01/2005 (with a zero at the begining)
why i used %e instead of %d??? the answer is very simple, there is a problem with de help about str_to_date:
%d: represents the days, but from 0 to 31 and...
%e: represents the days, but from 00 to 31.
that's the reason why we cannot use: str_to_date('00/00/0000',%d/%m/%Y), we must use str_to_date('00/00/0000','%e/%m/%Y')
Another way in order to change a string like: 00/00/0000 to a date is to use: str_to_date('00/00/0000','0%d/%m/%Y')
Posted by Regina Mullen on December 3 2005 10:25pm [Delete] [Edit]
Simple method of converting dates from any of
MM-DD-YYYY
MM/DD/YYYY
MM.DD.YYYY
(oldDate) to YYYY-MM-DD (addDate). Load date in as text and convert in one go using:
Caveat: make sure your text input doesn't have spaces.
Posted by Hyper Hacker on December 26 2005 10:54pm [Delete] [Edit]
In MySQL 4.0, and possibly others, UNIX_TIMESTAMP() doesn't work with dates before 1970. This query does the same, and works with any date from from Fri, 13 Dec 1901 20:45:54 to Tue, 19 Jan 2038 03:14:07. 'date' is the name of the DATETIME column you need a timestamp of.
SELECT (((TO_DAYS(date) * 86400) + TIME_TO_SEC(date)) - (TO_DAYS("1970-01-01") * 86400)) AS timestamp
If you're using PHP, note that date() accounts for DST and thus may appear to return incorrect results; also, don't forget to escape the quotes around 1970-01-01.
Posted by Noel Athaide on December 27 2005 8:23am [Delete] [Edit]
Keyphrases: Birthday reminder, select dates between
This might be useful. If you have a database containing 'name' and 'birthday' (as columns) then the following query will list the birthdays in the next 15 days. (16 to be more precise :-))
What I found unique about this problem is that the YEAR (of birth) will always be different and hence one cannot simply use a query like :
| SELECT * FROM `friends` WHERE
| `birthday` >= CURDATE()
| AND
| `birthday` <= ADDDATE(CURDATE(), INTERVAL 15 DAY);
because it would take the year into consideration.
The correct way, I believe, to get the desired result is as follows:
| SELECT * FROM `friends` WHERE (
| EXTRACT(MONTH FROM `birthday` ) = EXTRACT(MONTH FROM
| CURDATE())
| AND
| DAYOFMONTH(`birthday`) >= DAYOFMONTH(CURDATE())
| AND
| DAYOFMONTH(`birthday`) <= (DAYOFMONTH(CURDATE()) + 15)
| )
|
| OR (
| EXTRACT(MONTH FROM `birthday`) = EXTRACT(MONTH FROM
| ADDDATE(CURDATE(), INTERVAL 15 DAY))
| AND
| DAYOFMONTH(`birthday`) <= DAYOFMONTH(ADDDATE(CURDATE(),
| INTERVAL 15 DAY))
| )
The logic should be clear from the query itself. Note that in one place I use numerical addition (DAYOFMONTH(CURDATE()) + 15) while lower down I use the ADDDATE function. This distinction is important.
Would be happy if someone could refine the above method.
- Noel Athaide.
PS: Put this into a script and crontab it...and you have a simple Birthday reminder :-)
Posted by [name withheld] on January 12 2006 11:51pm [Delete] [Edit]
the birthday-reminder doesn't work the way it should be. I found the bug and fixed it. this is a working example:
SELECT user_birthdate,user_name,user_id , EXTRACT(MONTH FROM `user_birthdate` ) month, EXTRACT(DAY FROM `user_birthdate` ) day
FROM ".$db_prefix."users
WHERE
(
EXTRACT(MONTH FROM `user_birthdate` ) = EXTRACT(MONTH FROM CURDATE())
AND
DAYOFMONTH(`user_birthdate`) > DAYOFMONTH(CURDATE())
AND
DAYOFMONTH(`user_birthdate`) <= (DAYOFMONTH(CURDATE()) + 15)
)
OR
(
EXTRACT(MONTH FROM ADDDATE(CURDATE(), INTERVAL 15 DAY))<>EXTRACT(MONTH FROM CURDATE())
AND
EXTRACT(MONTH FROM `user_birthdate`) = EXTRACT(MONTH FROM ADDDATE(CURDATE(), INTERVAL 15 DAY))
AND
DAYOFMONTH(`user_birthdate`) <= DAYOFMONTH(ADDDATE(CURDATE(), INTERVAL 15 DAY))
)
ORDER BY month, day, user_id ASC
sorry for the strange name, but this is the way my table are named...
hope you like it
Posted by Stijn Tas on January 23 2006 4:07pm [Delete] [Edit]
I'm using this query for a birthday-reminder:
SELECT `geb_Geboorte`
FROM `gebruikers`
WHERE
DAYOFYEAR( curdate( ) ) <= dayofyear( `geb_Geboorte` )
AND
DAYOFYEAR( curdate( ) ) +15 >= dayofyear( `geb_Geboorte` );
I change the year of birthday to the current year.
Sorry for the dutch tablenames.
Posted by John L. on January 25 2006 3:56pm [Delete] [Edit]
It took me a bit of time to find how to select data based on time periods (such as for quarterly or yearly reports). You can use group by month(DateTypeColumn).
example- to find periodic totals:
SELECT [Year|Quarter|Month|Day](date) as Period,shipcountry,shipstate,shipcity,sum(products),sum(shipping),sum(tax)
FROM products NATURAL JOIN shipping NATURAL JOIN tax
GROUP BY Period,shipcountry,shipstate,shipcity
more here-
http://dev.mysql.com/doc/refman/5.0/en/date-and-time-functions.html
I suppose you could alter the start of quarterly periods by doing some arithmetic on the (date), but you might have to do some conversions.
Posted by [name withheld] on March 6 2006 7:32pm [Delete] [Edit]
Time arithmetic using CURTIME() is quite willing to type everything into integers rather than adding and subtracting seconds. For example, where log_time is a TIME column;
SELECT log_time AS Time FROM call_log
WHERE log_time >= (CURTIME( ) - 60 );
will fetch all results from the last 60 seconds. However,
SELECT log_time AS Time FROM call_log
WHERE log_time >= (CURTIME( ) - 900 );
will fetch all results from the last 9 minutes. 900 is interpreted, not as 900 seconds (15 minutes), but as 9:00. An hour is 10000 (1:00:00), not 3600 (36:00).
If you want to add seconds, use something like the following (for the last hour);
SELECT log_time AS Time FROM call_log
WHERE log_time >= (CURTIME( ) - SEC_TO_TIME(3600) );
Posted by Issac Goldstand on March 9 2006 12:34am [Delete] [Edit]
If you have a column of date values and you want to compare the day portion of them with today's date, taking in mind shorter months which might not contain all the dates in your set (example, billing systems or anything else which needs to run on each record or recordset on a given day of the month), you can try one of these (replacing '2002-04-30' with the date field you're comparing):
SELECT DATE_FORMAT(CURDATE()-INTERVAL 1 MONTH, CONCAT('%Y-%m-',DAY('2002-04-30')))+INTERVAL 1 MONTH;
This tends to "round down" on missing days - for example for dates ending in 30, this will translate to feb 28 (in february).
Posted by Marko Kruustük on April 5 2006 2:19pm [Delete] [Edit]
In reply to "David Berry on September 17 2004 9:08pm"
Problem: To find week start and end date with user specified start of the week day and user specified date for which the week is to be found.
David's solution does not work with user specified week start and end. It only works with normal week which is 1 and 7 as start and end correspondingly.
As I needed different starting day for week than Sunday or Monday for timesheet calculations, I had to come up with working solution:
...
date_sub(t.date, interval if(dayofweek(t.date)-$weekStartingDay >= 0, dayofweek(t.date)-$weekStartingDay, dayofweek(t.date)-$weekStartingDay+7) day) week_start
...
date_sub(t.date, interval if(dayofweek(t.date)-$weekStartingDay >= 0, dayofweek(t.date)-$weekStartingDay, dayofweek(t.date)-$weekStartingDay+7) - 6 day) week_end
...
This solution works fine for me, at least at the moment till I find some bug in it :)
Posted by [name withheld] on April 14 2006 3:57am [Delete] [Edit]
Use this to find the date of the last Friday. Please let me know if there is a more efficient way of doing this.
select if(DATE_FORMAT(curdate(),'%w')>4,date_sub(curdate(),INTERVAL DATE_FORMAT(curdate(),'%w')-5 DAY),date_sub(curdate(),INTERVAL DATE_FORMAT(curdate(),'%w')+2 DAY))
Posted by Horst Schirmeier on April 17 2006 11:16pm [Delete] [Edit]
Just another example on how to figure out how many days are until some birthdate (in order to do a range query, or get the "next" birthday):
SELECT name, birthday,
IF(DAYOFYEAR(birthday) >= DAYOFYEAR(NOW()),
DAYOFYEAR(birthday) - DAYOFYEAR(NOW()),
DAYOFYEAR(birthday) - DAYOFYEAR(NOW()) +
DAYOFYEAR(CONCAT(YEAR(NOW()),'-12-31')))
AS distance
FROM birthdates;
The + DAYOFYEAR(CONCAT(YEAR(NOW()),'-12-31')) (which is 366 or 365, depending on whether we're in a leap year or not) takes care of the New Year's Eve wrap around.
You could add WHERE distance <= 10 or ORDER BY distance ASC LIMIT 1 at the end of the query, for example.
Posted by Frederick Ducharme on May 9 2006 9:25pm [Delete] [Edit]
A simple way to get the number of month between 2 date :
SELECT PERIOD_DIFF(EXTRACT(YEAR_MONTH FROM mydate1), EXTRACT(YEAR_MONTH FROM mydate2)) AS month_interval
FROM ....
Posted by Dmitry Dimov on June 5 2006 7:07pm [Delete] [Edit]
Here's what I used to get a summary of some value by day of the week:
select date_format(date, "%W") AS `Day of the week`, sum(cost)
from daily_cost
group by `Day of the week`
order by date_format(date, "%w")
Output:
+-----------------+-----------+
| Day of the week | sum(cost) |
+-----------------+-----------+
| Sunday | 271.53 |
| Monday | 310.95 |
| Tuesday | 323.6 |
| Wednesday | 312.45 |
| Thursday | 301.76 |
| Friday | 294.76 |
| Saturday | 255.83 |
+-----------------+-----------+
To order results starting with Monday, change the "order by" expression to
order by (date_format(date, "%w") - 7) % 7
Posted by Jens Hopp on June 6 2006 1:04pm [Delete] [Edit]
LAST_DAY() with MySQL 3.23
Need to show the 1st day of the next month? - and were happy to find LAST_DAY() and just thought about adding one single day to its result? - and then discovered that you need MySQL 4+ for that?
Use this ugly chain of functions to show the 1st day of the next month - in MySQL 3.23:
FROM_DAYS(TO_DAYS(CONCAT(SUBSTRING(PERIOD_ADD(DATE_FORMAT(mydate,"%y%m" ),1),3,4),"01")))
You could subtract one day to simulate LAST_DAY() at all.
Posted by Richard Wolterink on July 10 2006 7:24am [Delete] [Edit]
I made a Stored Function which can covert an ISO 8601 (2006-07-05T13:30:00+02:00) date to a UNIX TIMESTAMP of the corresponding UTC or GMT datetime, so you can compare timestamps from different timezones with eachother. Hope this can help someone.
CREATE FUNCTION ISO8601TOUNIXTIMESTAMP (iso varchar(25))
RETURNS INTEGER(15)
DETERMINISTIC
BEGIN
DECLARE CONVTIME INTEGER(11);
SET CONVTIME = (SUBSTRING(iso,21,2) * 60) + SUBSTRING(iso,24,2);
IF SUBSTRING(iso,20,1) = '+' THEN
SET CONVTIME = 0 - CONVTIME;
END IF;
RETURN UNIX_TIMESTAMP(DATE_ADD(STR_TO_DATE(CONCAT(SUBSTRING(iso,1,10),' ',SUBSTRING(iso,12,8)),'%Y-%m-%d %H:%i:%s'), INTERVAL CONVTIME MINUTE));
END
Posted by Azizur Rahman on July 12 2006 10:08am [Delete] [Edit]
To get the first day of the current month:
SELECT ((PERIOD_ADD(EXTRACT(YEAR_MONTH FROM CURDATE()),0)*100)+1) as FirstDayOfTheMonth;
This will give you the first day of the month.
mysql> SELECT ((PERIOD_ADD(EXTRACT(YEAR_MONTH FROM CURDATE()),0)*100)+1) as FirstDayOfTheMonth;
+--------------------+
| FirstDayOfTheMonth |
+--------------------+
| 20060701 |
+--------------------+
1 row in set
To get the last day of the current month:
SELECT (SUBDATE(ADDDATE(CURDATE(),INTERVAL 1 MONTH),INTERVAL DAYOFMONTH(CURDATE())DAY)) AS LastDayOfTheMonth;
This will give you the first day of the month.
mysql> SELECT (SUBDATE(ADDDATE(CURDATE(),INTERVAL 1 MONTH),INTERVAL DAYOFMONTH(CURDATE())DAY)) AS LastDayOfTheMonth;
+-------------------+
| LastDayOfTheMonth |
+-------------------+
| 2006-07-31 |
+-------------------+
1 row in set
Hope this helps!
Posted by Jordan Gray on August 1 2006 11:17am [Delete] [Edit]
This function will return the difference between two dates as a string, in the format "Y year[s], M month[s], D day[s]" (pluralisation as appropriate):
|CREATE FUNCTION getDateDifferenceString(date1 DATE, date2 DATE) RETURNS VARCHAR(30)
| RETURN CONCAT(
| /* Years between */
| @years := TIMESTAMPDIFF(YEAR, date1, date2),
| IF (@years = 1, ' year, ', ' years, '),
| /* Months between */
| @months := TIMESTAMPDIFF(MONTH, DATE_ADD(date1, INTERVAL @years YEAR), date2),
| IF (@months = 1, ' month, ', ' months, '),
| /* Days between */
| @days := TIMESTAMPDIFF(DAY, DATE_ADD(date1, INTERVAL @years * 12 + @months MONTH), date2),
| IF (@days = 1, ' day', ' days')
| )
|;
It took a while to work this one out, so I hope this might save someone else the bother.
Posted by Daevid Vincent on August 4 2006 7:14am [Delete] [Edit]
I'm not sure why Horst Schirmeier did that very complex birthdate equation. Seems to me you could just do:
SET @DOYNOW = DAYOFYEAR(CURDATE());
SELECT (DAYOFYEAR(birthdate) - @DOYNOW) AS birthdays, birthdate, @DOYNOW, CURDATE()
FROM users
WHERE birthdate IS NOT NULL;
then if birthdays == 0, it's that persons birthday, otherwise you know if the birthday is in the future by how many days, or if you missed it and how many beers you owe them...
(although the missed/negative days seems to be off)
+-----------+------------+---------+------------+
| birthdays | birthdate | @DOYNOW | CURDATE() |
+-----------+------------+---------+------------+
| 83 | 1969-10-26 | 216 | 2006-08-04 |
| 3 | 1981-08-07 | 216 | 2006-08-04 |
| -1 | 1972-08-02 | 216 | 2006-08-04 |
| 0 | 1946-08-04 | 216 | 2006-08-04 |
| -151 | 1976-03-05 | 216 | 2006-08-04 |
+-----------+------------+---------+------------+
Shouldn't that -1 be -2 ?
Am I missing something obvious?
If I do "SELECT DATEDIFF('2006-08-01', CURDATE());" I get -2 as I expect.
So, I guess the real solution is to use this:
SET @YEAR = CONCAT(EXTRACT(YEAR FROM CURDATE()),'-');
SELECT DATEDIFF(CONCAT(@YEAR, DATE_FORMAT(birthdate, '%m-%d')), CURDATE()) AS birthdays, birthdate, CURDATE()
FROM users
WHERE birthdate IS NOT NULL;
+-----------+------------+------------+
| birthdays | birthdate | CURDATE() |
+-----------+------------+------------+
| 83 | 1969-10-26 | 2006-08-04 |
| 3 | 1981-08-07 | 2006-08-04 |
| -2 | 1972-08-02 | 2006-08-04 |
| 0 | 1946-08-04 | 2006-08-04 |
| -152 | 1976-03-05 | 2006-08-04 |
+-----------+------------+------------+
By the way, if you're using PHP or some other scripting language, you can get rid of the @YEAR stuff and just do:
DATEDIFF(DATE_FORMAT(birthdate, '".date('Y')."-%m-%d'), CURDATE()) AS birthdays
Posted by Arturas D. on August 18 2006 11:11am [Delete] [Edit]
Keyphrases: Birthday reminder
This is another query for the birthday remainder :
| SELECT * FROM `users`
| WHERE
| (
| DAYOFYEAR( NOW() ) > DAYOFYEAR( DATE_SUB(birthdate,INTERVAL 7 DAY) )
| AND
| DAYOFYEAR( NOW() ) <= DAYOFYEAR( DATE_SUB(birthdate,INTERVAL 7 DAY) )+7
| )
| OR
| (
| DAYOFYEAR( NOW() ) > DAYOFYEAR( birthdate )-7
| AND
| DAYOFYEAR( NOW() ) <= DAYOFYEAR( birthdate )
| );
Posted by jeremy levine on August 22 2006 7:18pm [Delete] [Edit]
Get the first day and/or last day of the current year.
This is the first day of the year ( simple )
SELECT MAKEDATE( EXTRACT(YEAR FROM CURDATE()),1);
This is the last day ( not you can not just replace the 1 with a 365 , some years you need a 366)
SELECT STR_TO_DATE(CONCAT(12,31,EXTRACT(YEAR FROM CURDATE())), '%m%d%Y') ;
Posted by Dave Green on September 14 2006 9:51pm [Delete] [Edit]
SERIAL DATES
------------
to convert dates stored as a double (Dateserial as used by microsoft etc i.e. 38883.8941421412. The whole number is the number of days since either 31/12/1899 or 01/01/1900, the fraction being the proportion of 1 day) into a dd/mm/yyyy hh:mm format:
note - MySQL requires the date taken from 31/12/1899, and even then the addition of number of days is still out by 1 because MySQL like Excel and other programs incorrectly assumes that the year 1900 was a leap year, when it wasn't for some reason.
The SQL to get the correct date is:-
ADDDATE(ADDDATE('1899-12-31 00:00',), INTERVAL -1 DAY)
The fraction of the time can be multiplied by the number of seconds in a day (84,600) and then added to the date as a number of seconds to get the time as well, so for a datetime the SQL is:-
ADDDATE(ADDDATE(ADDDATE('1899-12-31 00:00',), INTERVAL -1 DAY), INTERVAL (MOD(,1) * 86400) SECOND)
Sorry is this is a bit obvious, it just took me a while to find all this out. Hope it helps.
Posted by Erel Segal on November 1 2006 4:53am [Delete] [Edit]
Note that the order of arguments in TIMEDIFF is opposite than in TIMESTAMPDIFF, so:
TIMESTAMPDIFF(SECOND,expr1,expr2) = TIME_TO_SEC(TIMEDIFF(expr2,expr1))
Posted by Amit Kondhare on November 9 2006 7:52am [Delete] [Edit]
No ready made function is provided for validate date
This function work
(you can take what ever size you want in varchar(1-1024) )
CREATE FUNCTION IsDate (sIn varchar(1024)) RETURNS INT
BEGIN
declare tp int;
if length(date(sIn)) is not null then
set tp = 0;
else
set tp = 1;
end if;
RETURN tp;
END
If you find any bug for this please post it here as this is not complete soluction as date respond are not known
I will try to solve this
Posted by Ron A. on November 14 2006 2:39pm [Delete] [Edit]
Get date for first day of current week if first day of week is monday (SWEDEN, FRANCE, etc):
MONDAY
select date_sub(curdate(),INTERVAL WEEKDAY(curdate()) -0 DAY)
TUESDAY
select date_sub(curdate(),INTERVAL WEEKDAY(curdate()) -1 DAY)
AND SO ON...
Posted by Antonio Angelo on January 17 2007 2:12pm [Delete] [Edit]
The ISO 8601 week number is defined as the number of the week containing the first Thursday.
With this definition, the ISO week number corresponds to WEEK(date, 3) .
The following returns 1 for the week between 2003-12-29 and 2004-01-04:
| SELECT
| WEEK('2003-12-29', 3),
| WEEK('2004-01-04', 3)
Posted by Martin Minka on January 25 2007 5:23pm [Delete] [Edit]
I created this function to calculate "working day" difference of two dates. If you have table with list of holidays you may uncomment part in this function to exclude days of holidays also.
DELIMITER $$
DROP FUNCTION IF EXISTS `workdaydiff`$$
CREATE DEFINER=`root`@`%` FUNCTION `workdaydiff`(b date, a date) RETURNS int(11)
DETERMINISTIC
COMMENT 'working day difference for 2 dates'
BEGIN
DECLARE freedays int;
SET freedays = 0;
SET @x = DATEDIFF(b, a);
IF @x<0 THEN
SET @m = a;
SET a = b;
SET b = @m;
SET @m = -1;
ELSE
SET @m = 1;
END IF;
SET @x = abs(@x) + 1;
/* days in first week */
SET @w1 = WEEKDAY(a)+1;
SET @wx1 = 8-@w1;
IF @w1>5 THEN
SET @w1 = 0;
ELSE
SET @w1 = 6-@w1;
END IF;
/* days in last week */
SET @wx2 = WEEKDAY(b)+1;
SET @w2 = @wx2;
IF @w2>5 THEN
SET @w2 = 5;
END IF;
/* summary */
SET @weeks = (@x-@wx1-@wx2)/7;
SET @noweekends = (@weeks*5)+@w1+@w2;
/* Uncoment this if you want exclude also hollidays
SELECT count(*) INTO freedays FROM holliday WHERE d_day BETWEEN a AND b AND WEEKDAY(d_day)<5;
*/
SET @result = @noweekends-freedays;
RETURN @result*@m;
END$$
DELIMITER ;
Posted by Jemma Hussein on January 31 2007 3:28pm [Delete] [Edit]
If you want to select the time difference between two datetime columns and the fields may contain datetimes that are on different days, you can use the following if statement:
SELECT IF(TIME_TO_SEC(last_date)>=TIME_TO_SEC(first_date),
TIME_TO_SEC(last_date)-TIME_TO_SEC(first_date),
86400+(TIME_TO_SEC(last_date)-TIME_TO_SEC(first_date)))
FROM table;
This will return the time between the last_date and the first date, taking into account the values where first_date and last_date are on different days.
Posted by Will Jaspers on May 2 2007 3:58pm [Delete] [Edit]
NOTE: DateFormat cannot be used to format a TimeDiff calculation.
Example:
SELECT DATE_FORMAT(TIMEDIFF(`appointment_start`,`appointment_end`),'%H:%i:%s')) AS duration FROM appointments;
Correct Syntax:
SELECT TIMEDIFF(`appointment_start`,`appointment_end`) AS duration FROM appointments;
(Tested on MySQL 4.1.20)
Posted by [name withheld] on May 31 2007 5:11pm [Delete] [Edit]
My pick on birthdays remainders :
select date_format( date, "%d/%m" ), DAYOFYEAR( CURDATE( ) ), DAYOFYEAR( date )
from table
where DAYOFYEAR( date ) between DAYOFYEAR( CURDATE( ) ) - 15 and DAYOFYEAR( CURDATE( ) ) + 15
order by date_format( date, "%d/%m/%Y" )
Gabriel Reguly http://ppgr.com.br
Posted by Imran Chaudhry on June 11 2007 10:53am [Delete] [Edit]
As mentioned above STR_TO_DATE() is available as of MySQL 4.1.1.
This function can be useful if you are grouping rows by Week of Year and then want to produce a table with "Week Commencing" as the points on your X-axis.
So what do you do if you're codeshop is using pre-4.1?
Here's what I did. I have a table of events happening on a datetime. I wanted an event count by week with the date of the start of the week, assuming the week starts Monday.
I have exploited the group by function to extract the minimum datetime value which in my case is guaranteed to be at least once daily.
This will not work if your data is not being injected daily!
select
count(*) as 'count',
date_format(min(added_on), '%Y-%M-%d') as 'week commencing',
date_format(added_on, '%Y%u') as 'week'
from
system
where
added_on >= '2007-05-16'
group by
week
order by 3 desc;
+-------+-----------------+--------+
| count | week commencing | week |
+-------+-----------------+--------+
| 88 | 2007-June-04 | 200723 |
| 276 | 2007-May-28 | 200722 |
| 275 | 2007-May-21 | 200721 |
| 160 | 2007-May-16 | 200720 |
+-------+-----------------+--------+
Hope thats useful for someone !
Imran Chaudhry
Posted by Andrew Holloway on August 8 2007 6:01pm [Delete] [Edit]
Due to a bug in mysql versions prior to 5.0.36, there is a problem when performing multiple SEC_TO_TIME conversions and there are intermediate null values. It will turn the results after the first null into null values.
For example: if you have a table (date_diff) as follows:
|id | time1 | time2 |
+------+---------+-----------+
|1 | 9:30:05 | (null)|
|2 | 10:05:07| 10:05:17|
|3 | 11:00:03| 11:01:00|
|4 | 12:05:11| (null)|
and you run a query:
select sec_to_time(time_to_sec(time1) - time_to_sec(time2)) as diff from date_diff;
You will see results as so:
| diff |
+--------+
|00:00:00|
| (null)|
| (null)|
| (null)|
And a query excluding id 1 will result in:
| diff |
+--------+
|00:00:10|
|00:00:57|
|00:00:00|
A workaround would be to use a case statement:
select case when isnull(time_to_sec(time1) - time_to_sec(time2)) then null else sec_to_time(time_to_sec(time1) - time_to_sec(time2)) end as diff from date_diff;
Or, upgrade to a mysql version including this bug fix (#25643).
Posted by Marcel Brouillet on August 16 2007 1:37pm [Delete] [Edit]
To display the date of the monday preceding a given day, Bryan Donovan suggested the following:
> SELECT DISTINCT(STR_TO_DATE(CONCAT(YEARWEEK(starttime),'1'),'%x%v%w'))
> FROM test_events;
In fact, you need to be consistent in the type of weeks you use. The above would tell you that the Monday July 16 2007 is part of the week starting... Monday July 9 2007 !
This comes from week definition ambiguities (see WEEK() above). To prevent this, specify the mode on YEARWEEK to be Monday-based : pay attention to the extra parameter to the function YEARWEEK) below
+--------------------------------+
| DATE_FORMAT('2007-07-16',"%W") |
+--------------------------------+
| Monday |
+--------------------------------+
+----------------------------------------------------------+
| STR_TO_DATE(CONCAT(YEARWEEK('2007-07-16'),'1'),'%x%v%w') |
+----------------------------------------------------------+
| 2007-07-09 |
+----------------------------------------------------------+
+------------------------------------------------------------+
| STR_TO_DATE(CONCAT(YEARWEEK('2007-07-16',1),'1'),'%x%v%w') |
+------------------------------------------------------------+
| 2007-07-16 |
+------------------------------------------------------------+
One would expect that default_week_format has the same effect on WEEKDAY() than it has on WEEK() and that setting this variable to 1 or 3 would suffice. No, as of Mysql 5.0.26 it seems to have no effect:
SET default_week_format=1;
SELECT STR_TO_DATE(CONCAT(YEARWEEK('2007-07-16'),'1'),'%x%v%w')
+----------------------------------------------------------+
| 2007-07-09 |
+----------------------------------------------------------+
Posted by Dave Holden on September 6 2007 12:43am [Delete] [Edit]
ANNIVERSARIES ARE TRICKY!
-------------------------
For versions of MySQL previous to 4.1 it is quite difficult to determine if a date field's anniversary date falls within a specified date range. Day-of-year calculations fail because of leap years and the possibility that the date range you have specified spans a year boundary. Here is what I have come up with. Hopefully it can save someone the headache and Google Fever I had to go through to come up with it.
** SOME SELECT STATEMENT ...**
WHERE
((month(Date) BETWEEN month('[MyStartDate]') AND month('[MyEndDate]')
AND
month('[MyStartDate]') <= month('[MyEndDate]')
AND
(dayofmonth(Date) >= dayofmonth('[MyStartDate]') AND month(Date)=month('[MyStartDate]')
OR
dayofmonth(Date) <= dayofmonth('[MyEndDate]') AND month(Date)=month('[MyEndDate]')
OR
month(date) > month('[MyStartDate]') AND month(date) < month('[MyEndDate]')))
OR
(
month('[MyStartDate]') > month('[MyEndDate]')
AND
(dayofmonth(Date) >= dayofmonth('[MyStartDate]') AND month(Date)=month('[MyStartDate]')
OR
dayofmonth(Date) <= dayofmonth('[MyEndDate]') AND month(Date)=month('[MyEndDate]')
OR
month(Date) > month('[MyStartDate]')
OR month(Date) < month('[MyEndDate]')
)))
Posted by Darren Edwards on September 6 2007 6:22pm [Delete] [Edit]
I was looking for a solution where I could return the number of days, hours, Minutes and seconds between two entries in a table.
DATE_DIFF is not running on my mysql server as my provider uses mysql version 4.0.25
Solution was to use to days and std time functions to calculate the difference in one call.
The fields stored in the table(report_table) are
time(00:00:00),
date(0000-00-00) and record(enum) which tells the app the type of log stored. EG start or end of a report.
SELECT
(TO_DAYS( `end`.`date` ) - TO_DAYS( `start`.`date` ))
-
( second( `end`.`time` ) + (minute( `end`.`time` )*60) + (hour( `end`.`time` )*3600)
<
second( `start`.`time` ) + (minute( `start`.`time` )*60) + (hour( `start`.`time` )*3600))
AS `days` ,
SEC_TO_TIME(
(second( `end`.`time` ) + (minute( `end`.`time` )*60) + (hour( `end`.`time` )*3600) )
-
(second( `start`.`time` ) + (minute( `start`.`time` )*60) + (hour( `start`.`time` )*3600) )
) AS `hms`,
`start`.`time` as `start`,
`end`.`time` as `end`
FROM `report_table` AS `start` , `report_table` AS `end`
AND `start`.`record` = 'Report Begin'
AND `end`.`record` = 'Report End'
LIMIT 1
If there is no end of report then it will not return a result, as you would expect.
Posted by Robert Jaemmrich on October 12 2007 7:22am [Delete] [Edit]
Birthday reminder
The next birthday (including today!) is when the person is 1 year older than he/she was yesterday. So I use
mysql> select name,birthday,adddate(birthday,interval timestampdiff(year,adddate(birthday,interval 1 day),current_date)+1 year) as next_bd from person order by next_bd;
+----------+------------+------------+
| name | birthday | next_bd |
+----------+------------+------------+
| FooToday | 1970-10-12 | 2007-10-12 |
| Bar1 | 1990-12-25 | 2007-12-25 |
| Bar2 | 2000-01-25 | 2008-01-25 |
| Foo | 1980-02-29 | 2008-02-29 |
+----------+------------+------------+
4 rows in set (0.00 sec)
mysql> select name,birthday,adddate(birthday,interval timestampdiff(year,adddate(birthday,interval 1 day),'2008-10-12')+1 year) as next_bd from person order by next_bd;
+----------+------------+------------+
| name | birthday | next_bd |
+----------+------------+------------+
| FooToday | 1970-10-12 | 2008-10-12 |
| Bar1 | 1990-12-25 | 2008-12-25 |
| Bar2 | 2000-01-25 | 2009-01-25 |
| Foo | 1980-02-29 | 2009-02-28 |
+----------+------------+------------+
4 rows in set (0.00 sec)
As you can see, this is also working for leap years.
BTW: Is "2008-02-29" plus 1 year" really "2009-02-28"? ;-)
Posted by Aaron Davidson on December 6 2007 4:05pm [Delete] [Edit]
To test if a date is a valid date:
SET @testdate="2007-02-29";
SELECT IF(@testdate=DATE_ADD(DATE_ADD(@testdate,INTERVAL 1 DAY),INTERVAL -1 DAY),TRUE,FALSE);
Returns 0 (false)
SET @testdate="2008-02-29";
SELECT IF(@testdate=DATE_ADD(DATE_ADD(@testdate,INTERVAL 1 DAY),INTERVAL -1 DAY),TRUE,FALSE);
Returns 1 (true)
Posted by Mohamed Infiyaz Zaffer Khalid on December 12 2007 1:45pm [Delete] [Edit]
Finding a date before a given number of days
Often, for certain applications, we need to subtract some days from a given date to find another date. For example, in a library, we need to go 21 days behind from the current date and list the books that were taken before that date. This would be the overdue list.
Here is a simple SQL statement. This type of use is practically essential to most apps.
SELECT SUBDATE( '2007-12-12', INTERVAL 3 DAY ) ;
The line above will give the answer 2007-12-9. To explain it further, the function SUBDATE returns a date after subtracting a specified duration. In our example, the duration is 3 days. To indicate that we are dealing with DAYS, we use the term INTERVAL. So the function above can be explained as “what is the date, three days before today?”
Now if you want to find the date 20 days before TODAY or the current system date, this is what you should do:
SELECT SUBDATE( CURRENT_DATE, INTERVAL 20 DAY )
In the statement above, we are using one of the MySQL constants that hold the current date on the server. We count 20 days back and get the answer as a result.
Happy coding.
Khalid (itsols)
Posted by Marcus Matos on January 8 2008 1:02pm [Delete] [Edit]
Important: It should be known that MySQL >= 5.0.42 silently changes the behavior of comparing a DATE column to NOW().
See: http://bugs.mysql.com/bug.php?id=28929
This breaks many things since now queries using WHERE datecol = NOW() will return NULL where previously it would return results.
Use CURDATE() instead. I'm having to go back through years of code to fix this.
Posted by Tomek Kopec on January 17 2008 1:41pm [Delete] [Edit]
refering to the document section telling about intervals in date_add / date_sub functions describing example :
SELECT DATE_ADD('1999-01-01', INTERVAL 6/4 HOUR_MINUTE);
One can avoid falling into trap simply enclosing interval 6/4 into quotation marks so the query will be look like this:
SELECT DATE_ADD('1999-01-01', INTERVAL '6/4' HOUR_MINUTE);
This case the interval will be considered as regular string and no calculation will be performed before passing as argument
Posted by Mohamed Mahir on January 23 2008 6:31am [Delete] [Edit]
Earlier I used timediff in where clause worked perfectly but don't know why it is not working now especially after cpu usage exceeds in *in two different shared hosting*
query like
select * from table where timediff(sysdate(),datetimecolumn)<25
this gets rows of last 24 hours.
Posted by Phill Pafford on May 15 2008 3:02pm [Delete] [Edit]
IF you need to run a monthly report from the 1st of each month with the previous month date, you could use the case statement below.
SELECT CASE
WHEN MONTH(CURDATE()) = 01
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* Dec */
WHEN MONTH(CURDATE()) = 02
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* Jan */
WHEN MONTH(CURDATE()) = 03 AND (YEAR(CURDATE())%4 = 0)
THEN SUBDATE(CURDATE(), INTERVAL 29 DAY) /* Feb Leap Year */
WHEN MONTH(CURDATE()) = 03 AND (YEAR(CURDATE())%4 != 0)
THEN SUBDATE(CURDATE(), INTERVAL 28 DAY) /* Feb */
WHEN MONTH(CURDATE()) = 04
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* Mar */
WHEN MONTH(CURDATE()) = 05
THEN SUBDATE(CURDATE(), INTERVAL 30 DAY) /* Apr */
WHEN MONTH(CURDATE()) = 06
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* May */
WHEN MONTH(CURDATE()) = 07
THEN SUBDATE(CURDATE(), INTERVAL 30 DAY) /* Jun */
WHEN MONTH(CURDATE()) = 08
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* Jul */
WHEN MONTH(CURDATE()) = 09
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* Aug */
WHEN MONTH(CURDATE()) = 10
THEN SUBDATE(CURDATE(), INTERVAL 30 DAY) /* Sep */
WHEN MONTH(CURDATE()) = 11
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* Oct */
WHEN MONTH(CURDATE()) = 12
THEN SUBDATE(CURDATE(), INTERVAL 30 DAY) /* Nov */
ELSE SUBDATE(CURDATE(), INTERVAL 30 DAY) /* Defaults to 30 days */
END
Should return 'YYYY-MM-DD' from day and interval you run it on.
Example:
if the date is Jan 1st 2008 the case will return '2007-12-01'
Added this to get the 1st of the month when you run from any day of the month
SELECT CASE
WHEN MONTH(CURDATE()) = 01
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Dec */
WHEN MONTH(CURDATE()) = 02
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Jan */
WHEN MONTH(CURDATE()) = 03 AND (YEAR(CURDATE())%4 = 0)
THEN SUBDATE(CURDATE(), INTERVAL (29 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Feb Leap Year */
WHEN MONTH(CURDATE()) = 03 AND (YEAR(CURDATE())%4 != 0)
THEN SUBDATE(CURDATE(), INTERVAL (28 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Feb */
WHEN MONTH(CURDATE()) = 04
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Mar */
WHEN MONTH(CURDATE()) = 05
THEN SUBDATE(CURDATE(), INTERVAL (30 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Apr */
WHEN MONTH(CURDATE()) = 06
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* May */
WHEN MONTH(CURDATE()) = 07
THEN SUBDATE(CURDATE(), INTERVAL (30 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Jun */
WHEN MONTH(CURDATE()) = 08
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Jul */
WHEN MONTH(CURDATE()) = 09
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Aug */
WHEN MONTH(CURDATE()) = 10
THEN SUBDATE(CURDATE(), INTERVAL (30 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Sep */
WHEN MONTH(CURDATE()) = 11
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Oct */
WHEN MONTH(CURDATE()) = 12
THEN SUBDATE(CURDATE(), INTERVAL (30 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Nov */
ELSE SUBDATE(CURDATE(), INTERVAL (30 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Defaults to 30 days */
END
Posted by Thomas Schäfer on March 4 2008 2:41pm [Delete] [Edit]
Titel: Urlaubstage im laufenden Kalenderjahr anhand eines Arbeitstagemodells berechnen
Variablen $workable[First-Seventh] bool 1=Arbeitstag, 0=Kein Arbeitstag
$query ="
SELECT
SUM(effectiveworkdays(vrs.confirmed_from, vrs.confirmed_to, $workableFirst, $workableSecond, $workableThird, $workableFourth, $workableFifth, $workableSixth, $workableSeventh)) AS sum
FROM app_vacation_responses vrs
LEFT JOIN app_vacation_requests vrq ON vrs.request_id = vrq.vacation_id
WHERE vrq.requested_by = ". $employee_id ."
AND vrs.confirmed_from >= '". date('Y') ."-01-01'
AND vrs.confirmed_to <= '". date('Y') ."-12-31'
AND vrs.state = 1
group by vrq.requested_by
";
DELIMITER $$
DROP FUNCTION IF EXISTS `effectiveworkdays`$$
CREATE DEFINER=`myUserName`@`myHost` FUNCTION `effectiveworkdays`(STARTDATE date, ENDDATE date, WORKABLE1 integer, WORKABLE2 integer, WORKABLE3 integer, WORKABLE4 integer, WORKABLE5 integer, WORKABLE6 integer, WORKABLE7 integer) RETURNS int(11)
DETERMINISTIC
COMMENT 'effective working day for 2 dates'
BEGIN
DECLARE DAYCOUNT int;
DECLARE HOLIDAYCOUNT, HOLIDAYS int;
DECLARE STARTDAYS int;
DECLARE ENDDAYS int;
SET DAYCOUNT = 0;
SET HOLIDAYCOUNT = 0;
SET HOLIDAYS = 0;
SET STARTDAYS = TO_DAYS(STARTDATE) - 1 ;
SET ENDDAYS = TO_DAYS(ENDDATE);
IF (STARTDAYS <= ENDDAYS) THEN
WHILE (STARTDAYS <= ENDDAYS) DO
SET HOLIDAYCOUNT = 0;
IF(WORKABLE1=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=0) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
IF(WORKABLE2=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=1) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
IF(WORKABLE3=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=2) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
IF(WORKABLE4=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=3) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
IF(WORKABLE5=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=4) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
IF(WORKABLE6=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=5) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
IF(WORKABLE7=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=6) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
SET STARTDAYS = STARTDAYS + 1;
SET HOLIDAYS = HOLIDAYS + HOLIDAYCOUNT;
END WHILE;
END IF;
IF ((STARTDAYS = ENDDAYS) AND (DAYCOUNT = 0)) THEN
SET DAYCOUNT = 1;
END IF;
RETURN DAYCOUNT- HOLIDAYS;
END$$
DELIMITER ;
CREATE TABLE IF NOT EXISTS `prop_holidays` (
`holiday_id` int(11) NOT NULL auto_increment,
`name` varchar(50) NOT NULL,
`d_date` date NOT NULL,
`d_type` varchar(50) default NULL,
`d_subtype` varchar(50) default NULL,
PRIMARY KEY (`holiday_id`)
) ENGINE=MyISAM;
INSERT INTO `prop_holidays` (`holiday_id`, `name`, `d_date`, `d_type`, `d_subtype`) VALUES
(35, 'newYearsDay', '2008-01-01', 'Germany', 'BadenWuerttemberg'),
(36, 'epiphany', '2008-01-06', 'Germany', 'BadenWuerttemberg'),
(37, 'goodFriday', '2008-03-21', 'Germany', 'BadenWuerttemberg'),
(38, 'easterMonday', '2008-03-24', 'Germany', 'BadenWuerttemberg'),
(39, 'dayOfWork', '2008-05-01', 'Germany', 'BadenWuerttemberg'),
(40, 'ascensionDay', '2008-05-12', 'Germany', 'BadenWuerttemberg'),
(41, 'whitMonday', '2008-05-22', 'Germany', 'BadenWuerttemberg'),
(42, 'corpusChristi', '2008-10-03', 'Germany', 'BadenWuerttemberg'),
(43, 'germanUnificationDay', '2008-11-01', 'Germany', 'BadenWuerttemberg'),
(44, 'allSaintsDay', '2008-12-25', 'Germany', 'BadenWuerttemberg'),
(45, 'xmasDay', '2008-12-26', 'Germany', 'BadenWuerttemberg');
EXAMPLE FOR SYMFONY USERS
class VacationResponse extends BaseVacationResponse
{
public function getThisYearsLeaveDaysPaidByUserSum($employee_id){
$c = new Criteria();
$c->add(EmployeePeer::EMPLOYEE_ID, $this->getRequestParameter("id"));
$tmp = EmployeePeer::doSelect($c);
$employee = $tmp[0];
$schedule = $employee->getEmploymentContract()->getWorkSchedule();
$workableFirst = $schedule->getWorkableFirst() ==1?1:0;
$workableSecond = $schedule->getWorkableSecond() ==1?1:0;
$workableThird = $schedule->getWorkableThird() ==1?1:0;
$workableFourth = $schedule->getWorkableFourth() ==1?1:0;
$workableFifth = $schedule->getWorkableFifth() ==1?1:0;
$workableSixth = $schedule->getWorkableSixth() ==1?1:0;
$workableSeventh = $schedule->getWorkableSeventh()==1?1:0;
$query ="
SELECT
sum(effectiveworkdays2(vrs.confirmed_from, vrs.confirmed_to, $workableFirst, $workableSecond, $workableThird, $workableFourth, $workableFifth, $workableSixth, $workableSeventh)) AS sum
FROM app_vacation_responses vrs
LEFT JOIN app_vacation_requests vrq ON vrs.request_id = vrq.vacation_id
WHERE vrq.requested_by = ". $employee_id ."
AND vrs.confirmed_from >= '". date('Y') ."-01-01'
AND vrs.confirmed_to <= '". date('Y') ."-12-31'
AND vrs.state = 1
group by vrq.requested_by
";
$connection = Propel::getConnection();
$statement = $connection->prepareStatement($query);
$resultset = $statement->executeQuery();
$results = null;
foreach($resultset as $result){
if($result["sum"] < 0)
$results = 0;
else
$results = $result["sum"];
}
return $results;
}
}
Posted by Jyotsna Channagiri on March 31 2008 5:41pm [Delete] [Edit]
If you want to find out the difference between date column and integer column you can do like the following:
select DATE_ADD(,INTERVAL - UNIT) from
col_name_DATE : Should be DATE / DATETIME data type
col_name_INTEGER : Should be INTEGER data Type
UNIT : can be MINUTE,MONTH,....
Posted by M.H. J. on May 5 2008 3:48pm [Delete] [Edit]
For MySQL 4.1 you can use this query to select the month-difference between two dates, which also takes into account the amount of days of the starting month and ending month.
1. The first part is the period_diff function to get a total amount of months between two dates. Then 1 month is subtracted (because of the next two parts).
2. The second part is to calculate the part of the starting-month (results in 1 month for dates starting on the first of the month, like 01-01-2008)
3. The third part is to calculate the part of the ending-month (results in 0 for dates starting on the first of the month, like 01-02-2008)
PERIOD_DIFF(DATE_FORMAT(`end_date`,'%Y%m'),DATE_FORMAT(`start_date`,'%Y%m'))
-1
+ (TO_DAYS(LAST_DAY(`start_date`)) + 1 - TO_DAYS(DATE_FORMAT(`start_date`,'%Y-%m-%d')))/(TO_DAYS(LAST_DAY(`start_date`)) + 1 - to_days(DATE_FORMAT(`start_date`,'%Y-%m-01')))
+ (DAY(`end_date`)-1)/(TO_DAYS(LAST_DAY(`end_date`)) + 1 - TO_DAYS(DATE_FORMAT(`end_date`,'%Y-%m-01')))
Posted by Patrick Bernier on May 10 2008 6:06pm [Delete] [Edit]
A safe and simple way to calculate the age of someone/something:
CREATE FUNCTION age (_d DATETIME) RETURNS INTEGER
COMMENT 'Given birthdate, returns current age'
RETURN YEAR(NOW()) - YEAR(_d) - IF(DATE_FORMAT(_d, '%c%d') > DATE_FORMAT(NOW(), '%c%d'), 1, 0);
Posted by Andy Fugate on May 23 2008 8:56pm [Delete] [Edit]
I work for a publishing company and recently had a request to show the modification date/time for an article as either minutes ago, hours ago, yesterday, or date of last modification depending on how recently the article was last modified. Here's a copy of the case statement I used for this:
CASE
WHEN modified_date between date_sub(now(), INTERVAL 60 minute) and now() THEN concat(minute(TIMEDIFF(now(), modified_date)), ' minutes ago')
WHEN datediff(now(), modified_date) = 1 THEN 'Yesterday'
WHEN modified_date between date_sub(now(), INTERVAL 24 hour) and now() THEN concat(hour(TIMEDIFF(NOW(), modified_date)), ' hours ago')
ELSE date_format(modified_date, '%a, %m/%d/%y')
END
Note that the "yesterday" check occurs before the "hours" check. This is intentional so that hours will only be shown if the modification occurred during the current day.
Hope this is useful for someone else!
Add your own comment.
This section describes the functions that can be used to manipulate temporal values. See Section 10.3, “Date and Time Types”, for a description of the range of values each date and time type has and the valid formats in which values may be specified.
Name Description
ADDDATE()(v4.1.1)
Add dates
ADDTIME()(v4.1.1)
Add time
CONVERT_TZ()(v4.1.3)
Convert from one timezone to another
CURDATE()
Return the current date
CURRENT_DATE(), CURRENT_DATE
Synonyms for CURDATE()
CURRENT_TIME(), CURRENT_TIME
Synonyms for CURTIME()
CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP
Synonyms for NOW()
CURTIME()
Return the current time
DATE_ADD()
Add two dates
DATE_FORMAT()
Format date as specified
DATE_SUB()
Subtract two dates
DATE()(v4.1.1)
Extract the date part of a date or datetime expression
DATEDIFF()(v4.1.1)
Subtract two dates
DAY()(v4.1.1)
Synonym for DAYOFMONTH()
DAYNAME()(v4.1.21)
Return the name of the weekday
DAYOFMONTH()
Return the day of the month (1-31)
DAYOFWEEK()
Return the weekday index of the argument
DAYOFYEAR()
Return the day of the year (1-366)
EXTRACT
Extract part of a date
FROM_DAYS()
Convert a day number to a date
FROM_UNIXTIME()
Format UNIX timestamp as a date
GET_FORMAT()(v4.1.1)
Return a date format string
HOUR()
Extract the hour
LAST_DAY(v4.1.1)
Return the last day of the month for the argument
LOCALTIME(), LOCALTIME
Synonym for NOW()
LOCALTIMESTAMP, LOCALTIMESTAMP()(v4.0.6)
Synonym for NOW()
MAKEDATE()(v4.1.1)
Create a date from the year and day of year
MAKETIME(v4.1.1)
MAKETIME()
MICROSECOND()(v4.1.1)
Return the microseconds from argument
MINUTE()
Return the minute from the argument
MONTH()
Return the month from the date passed
MONTHNAME()(v4.1.21)
Return the name of the month
NOW()
Return the current date and time
PERIOD_ADD()
Add a period to a year-month
PERIOD_DIFF()
Return the number of months between periods
QUARTER()
Return the quarter from a date argument
SEC_TO_TIME()
Converts seconds to 'HH:MM:SS' format
SECOND()
Return the second (0-59)
STR_TO_DATE()(v4.1.1)
Convert a string to a date
SUBDATE()
When invoked with three arguments a synonym for DATE_SUB()
SUBTIME()(v4.1.1)
Subtract times
SYSDATE()
Return the time at which the function executes
TIME_FORMAT()
Format as time
TIME_TO_SEC()
Return the argument converted to seconds
TIME()(v4.1.1)
Extract the time portion of the expression passed
TIMEDIFF()(v4.1.1)
Subtract time
TIMESTAMP()(v4.1.1)
With a single argument, this function returns the date or datetime expression. With two arguments, the sum of the arguments
TO_DAYS()
Return the date argument converted to days
UNIX_TIMESTAMP()
Return a UNIX timestamp
UTC_DATE()(v4.1.1)
Return the current UTC date
UTC_TIME()(v4.1.1)
Return the current UTC time
UTC_TIMESTAMP()(v4.1.1)
Return the current UTC date and time
WEEK()
Return the week number
WEEKDAY()
Return the weekday index
WEEKOFYEAR()(v4.1.1)
Return the calendar week of the date (1-53)
YEAR()
Return the year
YEARWEEK()
Return the year and week
Here is an example that uses date functions. The following query selects all rows with a date_col value from within the last 30 days:
mysql> SELECT something FROM tbl_name
-> WHERE DATE_SUB(CURDATE(),INTERVAL 30 DAY) <= date_col;
Note that the query also selects rows with dates that lie in the future.
Functions that expect date values usually accept datetime values and ignore the time part. Functions that expect time values usually accept datetime values and ignore the date part.
Functions that return the current date or time each are evaluated only once per query at the start of query execution. This means that multiple references to a function such as NOW() within a single query always produce the same result. This principle also applies to CURDATE(), CURTIME(), UTC_DATE(), UTC_TIME(), UTC_TIMESTAMP(), and to any of their synonyms.
Beginning with MySQL 4.1.3, the CURRENT_TIMESTAMP(), CURRENT_TIME(), CURRENT_DATE(), and FROM_UNIXTIME() functions return values in the connection's current time zone, which is available as the value of the time_zone system variable. In addition, UNIX_TIMESTAMP() assumes that its argument is a datetime value in the current time zone. See Section 9.7, “MySQL Server Time Zone Support”.
Some date functions can be used with “zero” dates or incomplete dates such as '2001-11-00', whereas others cannot. Functions that extract parts of dates typically work with incomplete dates. For example:
mysql> SELECT DAYOFMONTH('2001-11-00'), MONTH('2005-00-00');
-> 0, 0
Other functions expect complete dates and return NULL for incomplete dates. These include functions that perform date arithmetic or that map parts of dates to names. For example:
mysql> SELECT DATE_ADD('2006-05-00',INTERVAL 1 DAY);
-> NULL
mysql> SELECT DAYNAME('2006-05-00');
-> NULL
• ADDDATE(date,INTERVAL expr unit), ADDDATE(expr,days)
When invoked with the INTERVAL form of the second argument, ADDDATE() is a synonym for DATE_ADD(). The related function SUBDATE() is a synonym for DATE_SUB(). For information on the INTERVAL unit argument, see the discussion for DATE_ADD().
mysql> SELECT DATE_ADD('1998-01-02', INTERVAL 31 DAY);
-> '1998-02-02'
mysql> SELECT ADDDATE('1998-01-02', INTERVAL 31 DAY);
-> '1998-02-02'
As of MySQL 4.1.1, the second syntax is allowed. When invoked with the days form of the second argument, MySQL treats it as an integer number of days to be added to expr.
mysql> SELECT ADDDATE('1998-01-02', 31);
-> '1998-02-02'
• ADDTIME(expr1,expr2)
ADDTIME() adds expr2 to expr1 and returns the result. expr1 is a time or datetime expression, and expr2 is a time expression.
mysql> SELECT ADDTIME('2007-12-31 23:59:59.999999',
-> '1 1:1:1.000002');
-> '2008-01-02 01:01:01.000001'
mysql> SELECT ADDTIME('01:00:00.999999', '02:00:00.999998');
-> '03:00:01.999997'
ADDTIME() was added in MySQL 4.1.1.
• CONVERT_TZ(dt,from_tz,to_tz)
CONVERT_TZ() converts a datetime value dt from the time zone given by from_tz to the time zone given by to_tz and returns the resulting value. Time zones are specified as described in Section 9.7, “MySQL Server Time Zone Support”. This function returns NULL if the arguments are invalid.
If the value falls out of the supported range of the TIMESTAMP type when converted from from_tz to UTC, no conversion occurs. The TIMESTAMP range is described in Section 10.1.2, “Overview of Date and Time Types”.
mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','GMT','MET');
-> '2004-01-01 13:00:00'
mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','+00:00','+10:00');
-> '2004-01-01 22:00:00'
Note
To use named time zones such as 'MET' or 'Europe/Moscow', the time zone tables must be properly set up. See Section 9.7, “MySQL Server Time Zone Support”, for instructions.
CONVERT_TZ() was added in MySQL 4.1.3.
If you intend to use CONVERT_TZ() while other tables are locked with LOCK TABLES, you must also lock the mysql.time_zone_name table.
• CURDATE()
Returns the current date as a value in 'YYYY-MM-DD' or YYYYMMDD format, depending on whether the function is used in a string or numeric context.
mysql> SELECT CURDATE();
-> '2008-06-13'
mysql> SELECT CURDATE() + 0;
-> 20080613
• CURRENT_DATE, CURRENT_DATE()
CURRENT_DATE and CURRENT_DATE() are synonyms for CURDATE().
• CURTIME()
Returns the current time as a value in 'HH:MM:SS' or HHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. (There is no .uuuuuu part before MySQL 4.1.13.) The value is expressed in the current time zone.
mysql> SELECT CURTIME();
-> '23:50:26'
mysql> SELECT CURTIME() + 0;
-> 235026.000000
• CURRENT_TIME, CURRENT_TIME()
CURRENT_TIME and CURRENT_TIME() are synonyms for CURTIME().
• CURRENT_TIMESTAMP, CURRENT_TIMESTAMP()
CURRENT_TIMESTAMP and CURRENT_TIMESTAMP() are synonyms for NOW().
• DATE(expr)
Extracts the date part of the date or datetime expression expr.
mysql> SELECT DATE('2003-12-31 01:02:03');
-> '2003-12-31'
DATE() is available as of MySQL 4.1.1.
• DATEDIFF(expr1,expr2)
DATEDIFF() returns expr1 – expr2 expressed as a value in days from one date to the other. expr1 and expr2 are date or date-and-time expressions. Only the date parts of the values are used in the calculation.
mysql> SELECT DATEDIFF('2007-12-31 23:59:59','2007-12-30');
-> 1
mysql> SELECT DATEDIFF('2010-11-30 23:59:59','2010-12-31');
-> -31
DATEDIFF() was added in MySQL 4.1.1.
• DATE_ADD(date,INTERVAL expr unit), DATE_SUB(date,INTERVAL expr unit)
These functions perform date arithmetic. The date argument specifies the starting date or datetime value. expr is an expression specifying the interval value to be added or subtracted from the starting date. expr is a string; it may start with a “-” for negative intervals. unit is a keyword indicating the units in which the expression should be interpreted.
The INTERVAL keyword and the unit specifier are not case sensitive.
The following table shows the expected form of the expr argument for each unit value.
unit Value Expected expr Format Version
MICROSECOND MICROSECONDS 4.1.1
SECOND SECONDS Pre-4.1
MINUTE MINUTES Pre-4.1
HOUR HOURS Pre-4.1
DAY DAYS Pre-4.1
WEEK WEEKS 5.0.0
MONTH MONTHS Pre-4.1
QUARTER QUARTERS 5.0.0
YEAR YEARS Pre-4.1
SECOND_MICROSECOND 'SECONDS.MICROSECONDS' 4.1.1
MINUTE_MICROSECOND 'MINUTES.MICROSECONDS' 4.1.1
MINUTE_SECOND 'MINUTES:SECONDS' 4.1.1
HOUR_MICROSECOND 'HOURS.MICROSECONDS' 4.1.1
HOUR_SECOND 'HOURS:MINUTES:SECONDS' 4.1.1
HOUR_MINUTE 'HOURS:MINUTES' Pre-4.1
DAY_MICROSECOND 'DAYS.MICROSECONDS' 4.1.1
DAY_SECOND 'DAYS HOURS:MINUTES:SECONDS' Pre-4.1
DAY_MINUTE 'DAYS HOURS:MINUTES' Pre-4.1
DAY_HOUR 'DAYS HOURS' Pre-4.1
YEAR_MONTH 'YEARS-MONTHS' Pre-4.1
The type values DAY_MICROSECOND, HOUR_MICROSECOND, MINUTE_MICROSECOND, SECOND_MICROSECOND, and MICROSECOND are allowed as of MySQL 4.1.1.
MySQL allows any punctuation delimiter in the expr format. Those shown in the table are the suggested delimiters. If the date argument is a DATE value and your calculations involve only YEAR, MONTH, and DAY parts (that is, no time parts), the result is a DATE value. Otherwise, the result is a DATETIME value.
As of MySQL 3.23, date arithmetic also can be performed using INTERVAL together with the + or - operator:
date + INTERVAL expr unit
date - INTERVAL expr unit
INTERVAL expr unit is allowed on either side of the + operator if the expression on the other side is a date or datetime value. For the - operator, INTERVAL expr unit is allowed only on the right side, because it makes no sense to subtract a date or datetime value from an interval.
mysql> SELECT '2008-12-31 23:59:59' + INTERVAL 1 SECOND;
-> '2009-01-01 00:00:00'
mysql> SELECT INTERVAL 1 DAY + '2008-12-31';
-> '2009-01-01'
mysql> SELECT '2005-01-01' - INTERVAL 1 SECOND;
-> '2004-12-31 23:59:59'
mysql> SELECT DATE_ADD('2000-12-31 23:59:59',
-> INTERVAL 1 SECOND);
-> '2001-01-01 00:00:00'
mysql> SELECT DATE_ADD('2010-12-31 23:59:59',
-> INTERVAL 1 DAY);
-> '2011-01-01 23:59:59'
mysql> SELECT DATE_ADD('2100-12-31 23:59:59',
-> INTERVAL '1:1' MINUTE_SECOND);
-> '2101-01-01 00:01:00'
mysql> SELECT DATE_SUB('2005-01-01 00:00:00',
-> INTERVAL '1 1:1:1' DAY_SECOND);
-> '2004-12-30 22:58:59'
mysql> SELECT DATE_ADD('1900-01-01 00:00:00',
-> INTERVAL '-1 10' DAY_HOUR);
-> '1899-12-30 14:00:00'
mysql> SELECT DATE_SUB('1998-01-02', INTERVAL 31 DAY);
-> '1997-12-02'
mysql> SELECT DATE_ADD('1992-12-31 23:59:59.000002',
-> INTERVAL '1.999999' SECOND_MICROSECOND);
-> '1993-01-01 00:00:01.000001'
If you specify an interval value that is too short (does not include all the interval parts that would be expected from the unit keyword), MySQL assumes that you have left out the leftmost parts of the interval value. For example, if you specify a unit of DAY_SECOND, the value of expr is expected to have days, hours, minutes, and seconds parts. If you specify a value like '1:10', MySQL assumes that the days and hours parts are missing and the value represents minutes and seconds. In other words, '1:10' DAY_SECOND is interpreted in such a way that it is equivalent to '1:10' MINUTE_SECOND. This is analogous to the way that MySQL interprets TIME values as representing elapsed time rather than as a time of day.
Because expr is treated as a string, be careful if you specify a non-string value with INTERVAL. For example, with an interval specifier of HOUR_MINUTE, 6/4 evaluates to 1.50 and is treated as 1 hour, 50 minutes:
mysql> SELECT 6/4;
-> 1.50
mysql> SELECT DATE_ADD('1999-01-01', INTERVAL 6/4 HOUR_MINUTE);
-> '1999-01-01 01:50:00'
If you add to or subtract from a date value something that contains a time part, the result is automatically converted to a datetime value:
mysql> SELECT DATE_ADD('1999-01-01', INTERVAL 1 DAY);
-> '1999-01-02'
mysql> SELECT DATE_ADD('1999-01-01', INTERVAL 1 HOUR);
-> '1999-01-01 01:00:00'
If you add MONTH, YEAR_MONTH, or YEAR and the resulting date has a day that is larger than the maximum day for the new month, the day is adjusted to the maximum days in the new month:
mysql> SELECT DATE_ADD('1998-01-30', INTERVAL 1 MONTH);
-> '1998-02-28'
Date arithmetic operations require complete dates and do not work with incomplete dates such as '2006-07-00' or badly malformed dates:
mysql> SELECT DATE_ADD('2006-07-00', INTERVAL 1 DAY);
-> NULL
mysql> SELECT '2005-03-32' + INTERVAL 1 MONTH;
-> NULL
• DATE_FORMAT(date,format)
Formats the date value according to the format string.
The following specifiers may be used in the format string. As of MySQL 3.23, the “%” character is required before format specifier characters. In earlier versions of MySQL, “%” was optional.
Specifier Description
%a Abbreviated weekday name (Sun..Sat)
%b Abbreviated month name (Jan..Dec)
%c Month, numeric (0..12)
%D Day of the month with English suffix (0th, 1st, 2nd, 3rd, …)
%d Day of the month, numeric (00..31)
%e Day of the month, numeric (0..31)
%f Microseconds (000000..999999)
%H Hour (00..23)
%h Hour (01..12)
%I Hour (01..12)
%i Minutes, numeric (00..59)
%j Day of year (001..366)
%k Hour (0..23)
%l Hour (1..12)
%M Month name (January..December)
%m Month, numeric (00..12)
%p AM or PM
%r Time, 12-hour (hh:mm:ss followed by AM or PM)
%S Seconds (00..59)
%s Seconds (00..59)
%T Time, 24-hour (hh:mm:ss)
%U Week (00..53), where Sunday is the first day of the week
%u Week (00..53), where Monday is the first day of the week
%V Week (01..53), where Sunday is the first day of the week; used with %X
%v Week (01..53), where Monday is the first day of the week; used with %x
%W Weekday name (Sunday..Saturday)
%w Day of the week (0=Sunday..6=Saturday)
%X Year for the week where Sunday is the first day of the week, numeric, four digits; used with %V
%x Year for the week, where Monday is the first day of the week, numeric, four digits; used with %v
%Y Year, numeric, four digits
%y Year, numeric (two digits)
%% A literal “%” character
%x x, for any “x” not listed above
The %v, %V, %x, and %X format specifiers are available as of MySQL 3.23.8. %f is available as of MySQL 4.1.1.
Ranges for the month and day specifiers begin with zero due to the fact that MySQL allows the storing of incomplete dates such as '2004-00-00' (as of MySQL 3.23).
As of MySQL 4.1.21, the language used for day and month names and abbreviations is controlled by the value of the lc_time_names system variable (Section 9.8, “MySQL Server Locale Support”).
As of MySQL 4.1.23, DATE_FORMAT() returns a string with a character set and collation given by character_set_connection and collation_connection so that it can return month and weekday names containing non-ASCII characters. Before 4.1.23, the return value is a binary string.
mysql> SELECT DATE_FORMAT('2009-10-04 22:23:00', '%W %M %Y');
-> 'Sunday October 2009'
mysql> SELECT DATE_FORMAT('2007-10-04 22:23:00', '%H:%i:%s');
-> '22:23:00'
mysql> SELECT DATE_FORMAT('1900-10-04 22:23:00',
-> '%D %y %a %d %m %b %j');
-> '4th 00 Thu 04 10 Oct 277'
mysql> SELECT DATE_FORMAT('1997-10-04 22:23:00',
-> '%H %k %I %r %T %S %w');
-> '22 22 10 10:23:00 PM 22:23:00 00 6'
mysql> SELECT DATE_FORMAT('1999-01-01', '%X %V');
-> '1998 52'
mysql> SELECT DATE_FORMAT('2006-06-00', '%d');
-> '00'
• DATE_SUB(date,INTERVAL expr unit)
See the description for DATE_ADD().
• DAY(date)
DAY() is a synonym for DAYOFMONTH(). It is available as of MySQL 4.1.1.
• DAYNAME(date)
Returns the name of the weekday for date. As of MySQL 4.1.21, the language used for the name is controlled by the value of the lc_time_names system variable (Section 9.8, “MySQL Server Locale Support”).
mysql> SELECT DAYNAME('1998-02-05');
-> 'Thursday'
• DAYOFMONTH(date)
Returns the day of the month for date, in the range 1 to 31, or 0 for dates such as '0000-00-00' or '2008-00-00' that have a zero day part.
mysql> SELECT DAYOFMONTH('1998-02-03');
-> 3
• DAYOFWEEK(date)
Returns the weekday index for date (1 = Sunday, 2 = Monday, …, 7 = Saturday). These index values correspond to the ODBC standard.
mysql> SELECT DAYOFWEEK('1998-02-03');
-> 3
• DAYOFYEAR(date)
Returns the day of the year for date, in the range 1 to 366.
mysql> SELECT DAYOFYEAR('1998-02-03');
-> 34
• EXTRACT(unit FROM date)
The EXTRACT() function uses the same kinds of unit specifiers as DATE_ADD() or DATE_SUB(), but extracts parts from the date rather than performing date arithmetic.
mysql> SELECT EXTRACT(YEAR FROM '1999-07-02');
-> 1999
mysql> SELECT EXTRACT(YEAR_MONTH FROM '1999-07-02 01:02:03');
-> 199907
mysql> SELECT EXTRACT(DAY_MINUTE FROM '1999-07-02 01:02:03');
-> 20102
mysql> SELECT EXTRACT(MICROSECOND
-> FROM '2003-01-02 10:30:00.000123');
-> 123
EXTRACT() was added in MySQL 3.23.0.
• FROM_DAYS(N)
Given a day number N, returns a DATE value.
mysql> SELECT FROM_DAYS(730669);
-> '2007-07-03'
Use FROM_DAYS() with caution on old dates. It is not intended for use with values that precede the advent of the Gregorian calendar (1582). See Section 11.7, “What Calendar Is Used By MySQL?”.
• FROM_UNIXTIME(unix_timestamp), FROM_UNIXTIME(unix_timestamp,format)
Returns a representation of the unix_timestamp argument as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. (There is no .uuuuuu part before MySQL 4.1.13.) The value is expressed in the current time zone. unix_timestamp is an internal timestamp value such as is produced by the UNIX_TIMESTAMP() function.
If format is given, the result is formatted according to the format string, which is used the same way as listed in the entry for the DATE_FORMAT() function.
mysql> SELECT FROM_UNIXTIME(1196440219);
-> '2007-11-30 10:30:19'
mysql> SELECT FROM_UNIXTIME(1196440219) + 0;
-> 20071130103019.000000
mysql> SELECT FROM_UNIXTIME(UNIX_TIMESTAMP(),
-> '%Y %D %M %h:%i:%s %x');
-> '2007 30th November 10:30:59 2007'
Note: If you use UNIX_TIMESTAMP() and FROM_UNIXTIME() to convert between TIMESTAMP values and Unix timestamp values, the conversion is lossy because the mapping is not one-to-one in both directions. For details, see the description of the UNIX_TIMESTAMP() function.
• GET_FORMAT(DATE|TIME|DATETIME, 'EUR'|'USA'|'JIS'|'ISO'|'INTERNAL')
Returns a format string. This function is useful in combination with the DATE_FORMAT() and the STR_TO_DATE() functions.
The possible values for the first and second arguments result in several possible format strings (for the specifiers used, see the table in the DATE_FORMAT() function description). ISO format refers to ISO 9075, not ISO 8601.
Function Call Result
GET_FORMAT(DATE,'USA')
'%m.%d.%Y'
GET_FORMAT(DATE,'JIS')
'%Y-%m-%d'
GET_FORMAT(DATE,'ISO')
'%Y-%m-%d'
GET_FORMAT(DATE,'EUR')
'%d.%m.%Y'
GET_FORMAT(DATE,'INTERNAL')
'%Y%m%d'
GET_FORMAT(DATETIME,'USA')
'%Y-%m-%d %H.%i.%s'
GET_FORMAT(DATETIME,'JIS')
'%Y-%m-%d %H:%i:%s'
GET_FORMAT(DATETIME,'ISO')
'%Y-%m-%d %H:%i:%s'
GET_FORMAT(DATETIME,'EUR')
'%Y-%m-%d %H.%i.%s'
GET_FORMAT(DATETIME,'INTERNAL')
'%Y%m%d%H%i%s'
GET_FORMAT(TIME,'USA')
'%h:%i:%s %p'
GET_FORMAT(TIME,'JIS')
'%H:%i:%s'
GET_FORMAT(TIME,'ISO')
'%H:%i:%s'
GET_FORMAT(TIME,'EUR')
'%H.%i.%s'
GET_FORMAT(TIME,'INTERNAL')
'%H%i%s'
As of MySQL 4.1.4, TIMESTAMP can also be used as the first argument to GET_FORMAT(), in which case the function returns the same values as for DATETIME.
mysql> SELECT DATE_FORMAT('2003-10-03',GET_FORMAT(DATE,'EUR'));
-> '03.10.2003'
mysql> SELECT STR_TO_DATE('10.31.2003',GET_FORMAT(DATE,'USA'));
-> '2003-10-31'
GET_FORMAT() is available as of MySQL 4.1.1.
• HOUR(time)
Returns the hour for time. The range of the return value is 0 to 23 for time-of-day values. However, the range of TIME values actually is much larger, so HOUR can return values greater than 23.
mysql> SELECT HOUR('10:05:03');
-> 10
mysql> SELECT HOUR('272:59:59');
-> 272
• LAST_DAY(date)
Takes a date or datetime value and returns the corresponding value for the last day of the month. Returns NULL if the argument is invalid.
mysql> SELECT LAST_DAY('2003-02-05');
-> '2003-02-28'
mysql> SELECT LAST_DAY('2004-02-05');
-> '2004-02-29'
mysql> SELECT LAST_DAY('2004-01-01 01:01:01');
-> '2004-01-31'
mysql> SELECT LAST_DAY('2003-03-32');
-> NULL
LAST_DAY() is available as of MySQL 4.1.1.
• LOCALTIME, LOCALTIME()
LOCALTIME and LOCALTIME() are synonyms for NOW().
• LOCALTIMESTAMP, LOCALTIMESTAMP()
LOCALTIMESTAMP and LOCALTIMESTAMP() are synonyms for NOW().
They were added in MySQL 4.0.6.
• MAKEDATE(year,dayofyear)
Returns a date, given year and day-of-year values. dayofyear must be greater than 0 or the result is NULL.
mysql> SELECT MAKEDATE(2001,31), MAKEDATE(2001,32);
-> '2001-01-31', '2001-02-01'
mysql> SELECT MAKEDATE(2001,365), MAKEDATE(2004,365);
-> '2001-12-31', '2004-12-30'
mysql> SELECT MAKEDATE(2001,0);
-> NULL
MAKEDATE() is available as of MySQL 4.1.1.
• MAKETIME(hour,minute,second)
Returns a time value calculated from the hour, minute, and second arguments.
mysql> SELECT MAKETIME(12,15,30);
-> '12:15:30'
MAKETIME() is available as of MySQL 4.1.1.
• MICROSECOND(expr)
Returns the microseconds from the time or datetime expression expr as a number in the range from 0 to 999999.
mysql> SELECT MICROSECOND('12:00:00.123456');
-> 123456
mysql> SELECT MICROSECOND('2009-12-31 23:59:59.000010');
-> 10
MICROSECOND() is available as of MySQL 4.1.1.
• MINUTE(time)
Returns the minute for time, in the range 0 to 59.
mysql> SELECT MINUTE('98-02-03 10:05:03');
-> 5
• MONTH(date)
Returns the month for date, in the range 1 to 12 for January to December, or 0 for dates such as '0000-00-00' or '2008-00-00' that have a zero month part.
mysql> SELECT MONTH('1998-02-03');
-> 2
• MONTHNAME(date)
Returns the full name of the month for date. As of MySQL 4.1.21, the language used for the name is controlled by the value of the lc_time_names system variable (Section 9.8, “MySQL Server Locale Support”).
mysql> SELECT MONTHNAME('1998-02-05');
-> 'February'
• NOW()
Returns the current date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. (There is no .uuuuuu part before MySQL 4.1.13.) The value is expressed in the current time zone.
mysql> SELECT NOW();
-> '2007-12-15 23:50:26'
mysql> SELECT NOW() + 0;
-> 20071215235026.000000
• PERIOD_ADD(P,N)
Adds N months to period P (in the format YYMM or YYYYMM). Returns a value in the format YYYYMM. Note that the period argument P is not a date value.
mysql> SELECT PERIOD_ADD(9801,2);
-> 199803
• PERIOD_DIFF(P1,P2)
Returns the number of months between periods P1 and P2. P1 and P2 should be in the format YYMM or YYYYMM. Note that the period arguments P1 and P2 are not date values.
mysql> SELECT PERIOD_DIFF(9802,199703);
-> 11
• QUARTER(date)
Returns the quarter of the year for date, in the range 1 to 4.
mysql> SELECT QUARTER('98-04-01');
-> 2
• SECOND(time)
Returns the second for time, in the range 0 to 59.
mysql> SELECT SECOND('10:05:03');
-> 3
• SEC_TO_TIME(seconds)
Returns the seconds argument, converted to hours, minutes, and seconds, as a TIME value. The range of the result is constrained to that of the TIME data type. A warning occurs if the argument corresponds to a value outside that range.
mysql> SELECT SEC_TO_TIME(2378);
-> '00:39:38'
mysql> SELECT SEC_TO_TIME(2378) + 0;
-> 3938
Note
You cannot use format "%X%V" to convert a year-week string to a date because the combination of a year and week does not uniquely identify a year and month if the week crosses a month boundary. To convert a year-week to a date, then you should also specify the weekday:
mysql> SELECT STR_TO_DATE('200442 Monday', '%X%V %W');
-> '2004-10-18'
• STR_TO_DATE(str,format)
This is the inverse of the DATE_FORMAT() function. It takes a string str and a format string format. STR_TO_DATE() returns a DATETIME value if the format string contains both date and time parts, or a DATE or TIME value if the string contains only date or time parts.
The date, time, or datetime values contained in str should be given in the format indicated by format. For the specifiers that can be used in format, see the DATE_FORMAT() function description. If str contains an illegal date, time, or datetime value, STR_TO_DATE() returns NULL.
Range checking on the parts of date values is as described in Section 10.3.1, “The DATETIME, DATE, and TIMESTAMP Types”. This means, for example, that a date with a day part larger than the number of days in a month is allowable as long as the day part is in the range from 1 to 31. Also, “zero” dates or dates with part values of 0 are allowed.
mysql> SELECT STR_TO_DATE('00/00/0000', '%m/%d/%Y');
-> '0000-00-00'
mysql> SELECT STR_TO_DATE('04/31/2004', '%m/%d/%Y');
-> '2004-04-31'
STR_TO_DATE() is available as of MySQL 4.1.1.
• SUBDATE(date,INTERVAL expr unit), SUBDATE(expr,days)
When invoked with the INTERVAL form of the second argument, SUBDATE() is a synonym for DATE_SUB(). For information on the INTERVAL unit argument, see the discussion for DATE_ADD().
mysql> SELECT DATE_SUB('2008-01-02', INTERVAL 31 DAY);
-> '2007-12-02'
mysql> SELECT SUBDATE('2008-01-02', INTERVAL 31 DAY);
-> '2007-12-02'
As of MySQL 4.1.1, the second syntax is allowed, where expr is a date or datetime expression and days is the number of days to be subtracted from expr.
mysql> SELECT SUBDATE('2008-01-02 12:00:00', 31);
-> '2007-12-02 12:00:00'
• SUBTIME(expr1,expr2)
SUBTIME() returns expr1 – expr2 expressed as a value in the same format as expr1. expr1 is a time or datetime expression, and expr2 is a time expression.
mysql> SELECT SUBTIME('2007-12-31 23:59:59.999999','1 1:1:1.000002');
-> '2007-12-30 22:58:58.999997'
mysql> SELECT SUBTIME('01:00:00.999999', '02:00:00.999998');
-> '-00:59:59.999999'
SUBTIME() was added in MySQL 4.1.1.
• SYSDATE()
Returns the current date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. (There is no .uuuuuu part before MySQL 4.1.13.)
• TIME(expr)
Extracts the time part of the time or datetime expression expr and returns it as a string.
mysql> SELECT TIME('2003-12-31 01:02:03');
-> '01:02:03'
mysql> SELECT TIME('2003-12-31 01:02:03.000123');
-> '01:02:03.000123'
TIME() is available as of MySQL 4.1.1.
• TIMEDIFF(expr1,expr2)
TIMEDIFF() returns expr1 – expr2 expressed as a time value. expr1 and expr2 are time or date-and-time expressions, but both must be of the same type.
mysql> SELECT TIMEDIFF('2000:01:01 00:00:00',
-> '2000:01:01 00:00:00.000001');
-> '-00:00:00.000001'
mysql> SELECT TIMEDIFF('2008-12-31 23:59:59.000001',
-> '2008-12-30 01:01:01.000002');
-> '46:58:57.999999'
TIMEDIFF() was added in MySQL 4.1.1.
• TIMESTAMP(expr), TIMESTAMP(expr1,expr2)
With a single argument, this function returns the date or datetime expression expr as a datetime value. With two arguments, it adds the time expression expr2 to the date or datetime expression expr1 and returns the result as a datetime value.
mysql> SELECT TIMESTAMP('2003-12-31');
-> '2003-12-31 00:00:00'
mysql> SELECT TIMESTAMP('2003-12-31 12:00:00','12:00:00');
-> '2004-01-01 00:00:00'
TIMESTAMP() is available as of MySQL 4.1.1.
• TIME_FORMAT(time,format)
This is used like the DATE_FORMAT() function, but the format string may contain format specifiers only for hours, minutes, and seconds. Other specifiers produce a NULL value or 0.
If the time value contains an hour part that is greater than 23, the %H and %k hour format specifiers produce a value larger than the usual range of 0..23. The other hour format specifiers produce the hour value modulo 12.
mysql> SELECT TIME_FORMAT('100:00:00', '%H %k %h %I %l');
-> '100 100 04 04 4'
• TIME_TO_SEC(time)
Returns the time argument, converted to seconds.
mysql> SELECT TIME_TO_SEC('22:23:00');
-> 80580
mysql> SELECT TIME_TO_SEC('00:39:38');
-> 2378
• TO_DAYS(date)
Given a date date, returns a day number (the number of days since year 0).
mysql> SELECT TO_DAYS(950501);
-> 728779
mysql> SELECT TO_DAYS('2007-10-07');
-> 733321
TO_DAYS() is not intended for use with values that precede the advent of the Gregorian calendar (1582), because it does not take into account the days that were lost when the calendar was changed. For dates before 1582 (and possibly a later year in other locales), results from this function are not reliable. See Section 11.7, “What Calendar Is Used By MySQL?”, for details.
Remember that MySQL converts two-digit year values in dates to four-digit form using the rules in Section 10.3, “Date and Time Types”. For example, '1997-10-07' and '97-10-07' are seen as identical dates:
mysql> SELECT TO_DAYS('1997-10-07'), TO_DAYS('97-10-07');
-> 729669, 729669
• UNIX_TIMESTAMP(), UNIX_TIMESTAMP(date)
If called with no argument, returns a Unix timestamp (seconds since '1970-01-01 00:00:00' UTC) as an unsigned integer. If UNIX_TIMESTAMP() is called with a date argument, it returns the value of the argument as seconds since '1970-01-01 00:00:00' UTC. date may be a DATE string, a DATETIME string, a TIMESTAMP, or a number in the format YYMMDD or YYYYMMDD. The server interprets date as a value in the current time zone and converts it to an internal value in UTC. Clients can set their time zone as described in Section 9.7, “MySQL Server Time Zone Support”.
mysql> SELECT UNIX_TIMESTAMP();
-> 1196440210
mysql> SELECT UNIX_TIMESTAMP('2007-11-30 10:30:19');
-> 1196440219
When UNIX_TIMESTAMP() is used on a TIMESTAMP column, the function returns the internal timestamp value directly, with no implicit “string-to-Unix-timestamp” conversion. If you pass an out-of-range date to UNIX_TIMESTAMP(), it returns 0, but please note that only basic range checking is performed (year from 1970 to 2038, month from 01 to 12, day from 01 from 31).
Note: If you use UNIX_TIMESTAMP() and FROM_UNIXTIME() to convert between TIMESTAMP values and Unix timestamp values, the conversion is lossy because the mapping is not one-to-one in both directions. For example, due to conventions for local time zone changes, it is possible for two UNIX_TIMESTAMP() to map two TIMESTAMP values to the same Unix timestamp value. FROM_UNIXTIME() will map that value back to only one of the original TIMESTAMP values. Here is an example, using TIMESTAMP values in the CET time zone:
mysql> SELECT UNIX_TIMESTAMP('2005-03-27 03:00:00');
+---------------------------------------+
| UNIX_TIMESTAMP('2005-03-27 03:00:00') |
+---------------------------------------+
| 1111885200 |
+---------------------------------------+
mysql> SELECT UNIX_TIMESTAMP('2005-03-27 02:00:00');
+---------------------------------------+
| UNIX_TIMESTAMP('2005-03-27 02:00:00') |
+---------------------------------------+
| 1111885200 |
+---------------------------------------+
mysql> SELECT FROM_UNIXTIME(1111885200);
+---------------------------+
| FROM_UNIXTIME(1111885200) |
+---------------------------+
| 2005-03-27 03:00:00 |
+---------------------------+
If you want to subtract UNIX_TIMESTAMP() columns, you might want to cast the result to signed integers. See Section 11.9, “Cast Functions and Operators”.
• UTC_DATE, UTC_DATE()
Returns the current UTC date as a value in 'YYYY-MM-DD' or YYYYMMDD format, depending on whether the function is used in a string or numeric context.
mysql> SELECT UTC_DATE(), UTC_DATE() + 0;
-> '2003-08-14', 20030814
UTC_DATE() is available as of MySQL 4.1.1.
• UTC_TIME, UTC_TIME()
Returns the current UTC time as a value in 'HH:MM:SS' or HHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. (There is no .uuuuuu part before MySQL 4.1.13.)
mysql> SELECT UTC_TIME(), UTC_TIME() + 0;
-> '18:07:53', 180753.000000
UTC_TIME() is available as of MySQL 4.1.1.
• UTC_TIMESTAMP, UTC_TIMESTAMP()
Returns the current UTC date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. (There is no .uuuuuu part before MySQL 4.1.13.)
mysql> SELECT UTC_TIMESTAMP(), UTC_TIMESTAMP() + 0;
-> '2003-08-14 18:08:04', 20030814180804.000000
UTC_TIMESTAMP() is available as of MySQL 4.1.1.
• WEEK(date[,mode])
This function returns the week number for date. The two-argument form of WEEK() allows you to specify whether the week starts on Sunday or Monday and whether the return value should be in the range from 0 to 53 or from 1 to 53. If the mode argument is omitted, the value of the default_week_format system variable is used (or 0 before MySQL 4.0.14). See Section 5.1.3, “System Variables”.
The following table describes how the mode argument works.
First day
Mode of week Range Week 1 is the first week …
0 Sunday 0-53 with a Sunday in this year
1 Monday 0-53 with more than 3 days this year
2 Sunday 1-53 with a Sunday in this year
3 Monday 1-53 with more than 3 days this year
4 Sunday 0-53 with more than 3 days this year
5 Monday 0-53 with a Monday in this year
6 Sunday 1-53 with more than 3 days this year
7 Monday 1-53 with a Monday in this year
A mode value of 3 can be used as of MySQL 4.0.5. Values of 4 and above can be used as of MySQL 4.0.17.
mysql> SELECT WEEK('1998-02-20');
-> 7
mysql> SELECT WEEK('1998-02-20',0);
-> 7
mysql> SELECT WEEK('1998-02-20',1);
-> 8
mysql> SELECT WEEK('1998-12-31',1);
-> 53
Note: In MySQL 4.0, WEEK(date,0) was changed to match the calendar in the USA. Before that, WEEK() was calculated incorrectly for dates in the USA. (In effect, WEEK(date) and WEEK(date,0) were incorrect for all cases.)
Note that if a date falls in the last week of the previous year, MySQL returns 0 if you do not use 2, 3, 6, or 7 as the optional mode argument:
mysql> SELECT YEAR('2000-01-01'), WEEK('2000-01-01',0);
-> 2000, 0
One might argue that MySQL should return 52 for the WEEK() function, because the given date actually occurs in the 52nd week of 1999. We decided to return 0 instead because we want the function to return “the week number in the given year.” This makes use of the WEEK() function reliable when combined with other functions that extract a date part from a date.
If you would prefer the result to be evaluated with respect to the year that contains the first day of the week for the given date, use 0, 2, 5, or 7 as the optional mode argument.
mysql> SELECT WEEK('2000-01-01',2);
-> 52
Alternatively, use the YEARWEEK() function:
mysql> SELECT YEARWEEK('2000-01-01');
-> 199952
mysql> SELECT MID(YEARWEEK('2000-01-01'),5,2);
-> '52'
• WEEKDAY(date)
Returns the weekday index for date (0 = Monday, 1 = Tuesday, … 6 = Sunday).
mysql> SELECT WEEKDAY('2008-02-03 22:23:00');
-> 6
mysql> SELECT WEEKDAY('2007-11-06');
-> 1
• WEEKOFYEAR(date)
Returns the calendar week of the date as a number in the range from 1 to 53. WEEKOFYEAR() is a compatibility function that is equivalent to WEEK(date,3).
mysql> SELECT WEEKOFYEAR('1998-02-20');
-> 8
WEEKOFYEAR() is available as of MySQL 4.1.1.
• YEAR(date)
Returns the year for date, in the range 1000 to 9999, or 0 for the “zero” date.
-> 2008
• YEARWEEK(date), YEARWEEK(date,mode)
Returns year and week for a date. The mode argument works exactly like the mode argument to WEEK(). The year in the result may be different from the year in the date argument for the first and the last week of the year.
mysql> SELECT YEARWEEK('1987-01-01');
-> 198653
Note that the week number is different from what the WEEK() function would return (0) for optional arguments 0 or 1, as WEEK() then returns the week in the context of the given year.
YEARWEEK() was added in MySQL 3.23.8.
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User Comments
Posted by Isaac Shepard on October 11 2003 2:53pm [Delete] [Edit]
If you're looking for generic SQL queries that will allow you to get the days, months, and years between any two given dates, you might consider using these. You just need to substitute date1 and date2 with your date expressions.
NOTE: Some of these formulas are complex because they account for all cases where date1 < date2, date1 = date2, and date1 > date2. Additionally, these formulas can be used in very generic queries where aliases and temporary variables are not allowed.
Number of days between date1 and date2:
TO_DAYS(date2) - TO_DAYS(date1)
Number of months between date1 and date2:
IF((((YEAR(date2) - 1) * 12 + MONTH(date2)) - ((YEAR(date1) - 1) * 12 + MONTH(date1))) > 0, (((YEAR(date2) - 1) * 12 + MONTH(date2)) - ((YEAR(date1) - 1) * 12 + MONTH(date1))) - (MID(date2, 9, 2) < MID(date1, 9, 2)), IF((((YEAR(date2) - 1) * 12 + MONTH(date2)) - ((YEAR(date1) - 1) * 12 + MONTH(date1))) < 0, (((YEAR(date2) - 1) * 12 + MONTH(date2)) - ((YEAR(date1) - 1) * 12 + MONTH(date1))) + (MID(date1, 9, 2) < MID(date2, 9, 2)), (((YEAR(date2) - 1) * 12 + MONTH(date2)) - ((YEAR(date1) - 1) * 12 + MONTH(date1)))))
Number of years between date1 and date2:
IF((YEAR(date2) - YEAR(date1)) > 0, (YEAR(date2) - YEAR(date1)) - (MID(date2, 6, 5) < MID(date1, 6, 5)), IF((YEAR(date2) - YEAR(date1)) < 0, (YEAR(date2) - YEAR(date1)) + (MID(date1, 6, 5) < MID(date2, 6, 5)), (YEAR(date2) - YEAR(date1))))
Now for some comments about these.
1. These results return integer number of years, months, and days. They are "floored." Thus, 1.4 days would display as 1 day, and 13.9 years would display as 13 years. Likewise, -1.4 years would display as -1 year, and -13.9 months would display as -13 months.
2. Note that I use boolean expressions in many cases. Because boolean expressions evaluate to 0 or 1, I can use them to subtract or add 1 from the total based on a condition.
For example, to calculate the number of years between to dates, first simply subtract the years. The problem is that doing so isn't always correct. Consider the number of years between July 1, 1950 and May 1, 1952. Technically, there is only one full year between them. On July 1, 1952 and later, there will be two years. Therefore, you should subtract one year in case the date hasn't yet reached a full year. This is done by checking the if the second month-day is before the first month-
day. If so, this results in a value of 1, which is subtracted from the total. The IF statements are in the formula because we must add one year when dealing with the dates in the opposite order, and we must not add or subtract anything when the difference of the date years is zero.
3. To get the month-day, I use MID. This is better
than using RIGHT, since it will work for both dates
and datetimes.
4. Unlike many other solutions, these queries should
work with dates prior to 01/01/1970.
Posted by Aurelio Sablone on December 6 2002 8:34am [Delete] [Edit]
In order to get the number of seconds between two
datetime values in a table, you could use the
following: SELECT unix_timestamp(date1) -
unix_timestamp(date2) FROM table_name
Posted by [name withheld] on February 6 2003 4:19pm [Delete] [Edit]
Spent some time trying to work out how to calculate the month start x months ago ( so that I can create historical stats on the fly)
here is what I came up with..
((PERIOD_ADD(EXTRACT(YEAR_MONTH FROM CURDATE()),-6)*100)+1)
this gives you the first day of the month six months before the start of the current month in datetime format
Posted by Adam Tylmad on July 28 2003 10:28pm [Delete] [Edit]
To get the date difference between two date-type columns,
use this formula:
sec_to_time(unix_timestamp(EndDateTime) -
unix_timestamp(StartDateTime))
where StartDateTime and EndDateTime are the two columns
/A
Posted by Filip Wolak on August 4 2003 6:44am [Delete] [Edit]
Several times i have come to a followng date/time problem:
In the table i am storing both date and time information in the datetime column. Querying, I want to receive COUNTed results grouped by date, and not date and time. I came to the easy solution:
SELECT DATE_FORMAT(postdate, '%Y-%m-%d') AS dd, COUNT(id) FROM MyTable GROUP BY dd;
I suppose this solution to be quite slow (date formatting).
Later, i 'upgraded' this query to use the string function:
SELECT substring(postdate, 1,10) AS dd, COUNT(id) FROM MyTable GROUP BY dd;
knowing, that the result is in the fixed format. Works faster.
Posted by Stoyan Stefanov on August 16 2003 8:05pm [Delete] [Edit]
Hope this will help somebody. The way I found to sum time:
SELECT SEC_TO_TIME( SUM( TIME_TO_SEC( `time` ) ) ) AS total_time FROM time_table;
Posted by Gerard Manko on December 17 2003 9:27am [Delete] [Edit]
Comparing Dates when using MS Access and MyODBC
If you are using MS Access and have created Access queries to substitute for views (which are not yet available in mySQL), you can use the following syntax ro perform date comparisons and avoid the dreaded "ODBC -- call failed" error:
Select * from [Task Effort Summary]
Where ((Date() + 0) > CLng([Task Effort Summary].[s_end]))
This particular example retuns tasks that are overdue (where todays date is past the scheduled end date). This query was developed for reports on a TUTOS database.
Posted by [name withheld] on January 9 2004 7:59pm [Delete] [Edit]
Note that the built-in default values for the DATE and DATEFIELD column types is out of range. For example, 0000-00-00 is a valid way of expressing NULL, but if the column is set as NOT NULL, 0000-00-00 is still the default value. This can cause problems with some applications using MySQL.
Posted by asdacfd dsfdsf on January 27 2004 3:25am [Delete] [Edit]
I was looking for a function to detect if the current week is odd or even. I could not find one so I use this:
MOD((DATE_FORMAT(CURDATE(),"%v")),2)
The output is a '0'(even) or a '1'(odd)
Posted by Steve West on February 15 2004 10:49pm [Delete] [Edit]
To create a DATETIME of NOW() in UTC without upgrading to 4.1.1, just use:
DATE_ADD( '1970-01-01', INTERVAL UNIX_TIMESTAMP() SECOND )
Posted by [name withheld] on March 4 2004 9:39am [Delete] [Edit]
workaround for STR_TO_DATE pre version 4.1.1. ugly but it seems to work fine.
assumption: you know the format of the received date (in the below example the format is mm/dd/yy, m/d/yy, mm/dd/yyyy, etc)
the statement extracts the year by locating the index of the second '/' and reading from the right of the string to that index. the index of the second is '/' is found by using LOCATE with the index of the first '/'.
it extracts the day by locating the indeces of the first and second '/' and reading between them
it extracts the month by locating the index of the first '/' and reading from the left of the string to that index.
it then CONCATs the year month and day pieces together separating them with hyphens.
lastly, it lets DATE_FORMAT do its magic on the string.
(replace the test string '1/11/03' with your field name, etc)
select DATE_FORMAT( CONCAT( RIGHT( '1/11/03' , length( '1/11/03') - LOCATE('/', '1/11/03' , LOCATE('/', '1/11/03' ) + 1 ) ) , '-' , LEFT( '1/11/03' , LOCATE('/', '1/11/03' ) - 1 ) , '-', SUBSTRING( '1/11/03' , LOCATE('/', '1/11/03' ) + 1, LOCATE('/', '1/11/03' , LOCATE('/', '1/11/03' ) + 1 ) - LOCATE('/', '1/11/03' ) - 1 ) ) , '%Y-%m-%d' )
Posted by Olav Alexander Mjelde on March 15 2004 11:15am [Delete] [Edit]
Lets say you have the mysql before 4.1.1 (where timediff() was implementet), and you want to do a timediff.
I wanted to make a "active users" on my page, but I found out that I didnt have the timediff function (to find persons which have been active within 5 minutes).
So, I figured this query out:
SELECT nick FROM `users` WHERE TO_DAYS( NOW( ) ) - TO_DAYS( last_login ) <=1 AND DATE_FORMAT( CURRENT_TIMESTAMP( ) , '%H%i' ) - DATE_FORMAT( last_login, '%H%i' ) <=5 ORDER BY `nick` ASC;
it selects the field nick (which is the only one to be displayd) and then it filters for 1 day or less in age of activity. after that, it filters for 5 minutes or less in activity.
first you need to filter away the other days, or your script might get fooled to think that yesterdays login was todays.
I'm currently using this, and it works fine!
on the other page, you of course need to update the timestamp field (when session excists, on reload)
Posted by Cherice Scharf on April 5 2004 11:24am [Delete] [Edit]
Here is an example to convert various user inputs for a date field on an ASP page (VBScript) that will convert common formats (i.e., m/d/yy, mm/dd/yyyy, etc.) to MySQL database format of (yyyy-mm-dd). The function begins by establishing that there is a date in the field. Then splits the date (converted to string) into three parts by locating "/". DateArray(0), DateArray(1), DateArray(2) hold the month, day and year, respectively. These are then checked for the amount of digits, if there are not enough digits in month or day then a leading zero is added. If there are only two digits on the year (ie "04") then a leading "20" is added.
Function ConvertInputDate(varDate)
If (Len(Trim(varDate)) > 0) Then
DateArray=Split(CStr(varDate),"/")
IF Len(Trim(DateArray(0))) < 2 Then
DateArray(0) = "0" & DateArray(0)
End If
If Len(Trim(DateArray(1))) < 2 Then
DateArray(1) = "0" & DateArray(1)
End If
If Len(Trim(DateArray(2))) < 4 Then DateArray(2) = "20" & DateArray(2)
End If
varDate = DateArray(2) & "-" & DateArray(0) & "-" & DateArray(1)
End If
End Function
*Please note if a user does not use two slashes this function will not work. It is best to indicate "mm/dd/yy" near the label on the page. It will take 4/6/04, 10/6/04, 3/16/2004 and all combinations with two slashes.
Posted by Jason Richard on April 9 2004 7:20am [Delete] [Edit]
I had a problem with my login script using PHP and MySQL when daylight savings time (DST) came around this year.
I was using MYSQL NOW() function to add the current date and time to the user's record into a datetime field. When DST came into effect newly entered login times were an hour slow (I'm in EST). Since the last login is to be updated only if an hour or more has passed since the last login this was a big problem!
The problem is that PHP takes DST into account and MySQL does not (as far as I know) and I was entering the time using MySQL's NOW() function and then comparing the value returned by PHP's time() function.
A very simple solution to this is the following. Note the PHP time format string 'YmdHis' - it formats to YYYYMMDDHHMMSS which is what MySQL expects for a date/time field.
$now = time();
$lastLogin = strtotime($row['lastLogin']);
$diff = $now - $lastLogin;
$now = date('YmdHis',$now)
if($diff > 3600) { // 3600 seconds is 1 hour
$query = 'UPDATE members SET logins = logins + 1, lastLogin = '.$now.' WHERE memberID = '.$SEC_ID;
mysql_query($query);
}
Now the date entered is the PHP time (that accounts for DST) and we are comparing it to PHP time so all is well.
I think this approach will work well for any time you wish to enter a date into MySQL using PHP. Just format the date using the "YmdHis" format string and use the strtotime() function to read a date retrieved from MySQL.
The advantage to this approach rather than just entering the "normal" PHP date into a char or text field is that the dates are "human" readable in the table and all the MySQL date/time functions are available for future queries.
Posted by Martin Schwedes on April 25 2004 9:11am [Delete] [Edit]
to localize the weekday:
SELECT ELT( WEEKDAY('2004-04-10')+1, 'Montag','Dienstag','Mittwoch','Donnerstag','Freitag','Samstag','Sonntag');
long version with month:
SELECT DATE_FORMAT( '2004-04-10', CONCAT( ELT( WEEKDAY('2004-04-10')+1, 'Montag','Dienstag','Mittwoch','Donnerstag','Freitag','Samstag','Sonntag'),', %d. ', ELT( MONTH('2004-04-10'), 'Januar','Februar','März','April','Mai','Juni','Juli','August','September','Oktober','November','Dezember'),' %Y'));
--> Samstag, 10. April 2004
same for unix-timestamp:
SELECT DATE_FORMAT( FROM_UNIXTIME(1081548000), CONCAT( ELT( WEEKDAY(FROM_UNIXTIME(1081548000))+1, 'Mo','Di','Mi','Do','Fr','Sa','So'),', %d. ', ELT( MONTH(FROM_UNIXTIME(1081548000)), 'Jan.','Feb.','März','April','Mai','Juni','Juli','Aug.','Sept.','Okt.','Nov.','Dez.'),' %Y'));
--> Sa, 10. April 2004
Posted by Philippe Poelvoorde on April 30 2004 5:50am [Delete] [Edit]
I had to query a table and retrieve rows that were added only today, so :
select id from my_table
where
timestamp < date_format(date_add(CURRENT_TIMESTAMP(), interval 1 day),'%Y%m%d000000')
AND
timestamp >= date_format(CURRENT_TIMESTAMP(),'%Y%m%d000000')
starting with MySQL 4.0, you could also use the BETWEEN ... AND syntax.
If anyone has a better query to do that, let me know.
Posted by Michael Marcus on May 1 2004 2:41pm [Delete] [Edit]
After reading numerous articles and posts regarding converting back and forth between SQL datetime and VBscript datetime, I opted for the simplest solution for my databases. I simply save all datetime values in varchar(20) fields and call on either MySQL or VBscript functions to get datetime values or check/convert datetime values. For example:
currentDT = CStr(cn.execute("SELECT NOW()").Fields(0).Value)
will fetch current datetime in the SQL server's datetime format and then convert it to a string. [Obviously, cn is set by Set cn = Server.CreateObject("ADODB.Connection") to create the database connection, then the database is opened with a cn.open (parameters).]
You can then save this string to an appropriate field such as 'flddate_added' which is formatted as varchar(20).
When retrieving the flddate_added value, you can use this VBscript code to check if the value is indeed a datetime value and convert it to the datetime format of the user's computer"
if IsDate(flddate_added) then
=CDate(flddate_added) ' convert to user's system format for display using user's codepage
else
=flddate_added ' just display the string
end if
The above methods allow me to get around all of the issues regarding VBscript's datetime display format differences depending on the system local.
Posted by Ray Morris on July 15 2004 4:37pm [Delete] [Edit]
Posted by Filip Wolak:
> Several times i have come to a followng date/time problem:
> In the table i am storing both date and time information in the datetime
> column. Querying, I want to receive COUNTed results grouped by date,
> and not date and time.
...
> SELECT substring(postdate, 1,10) ...
If it's a DATETIME column than substring is not appropriate -
it's logically nonsensical of course, and just happens to work
in some version of MySQL because the DATETIME happens
to be represented by a string in some contexts.
Better would be to treat the DATETIME as a DATETIME
rather than as a string, which will work in future versions
of MYSQL and in other RDMS:
SELECT DATE(postdate) ...
Posted by David Lyon on July 17 2004 4:12pm [Delete] [Edit]
Here is another VB/ASP function for converting Dates from standard to MySQL format. Cherise gave a nice example above, but it has extra complexity due to the use of arrays and also may be proned to user input errors.
The following example will work based on the Localization settings of the server on which it is run. So it shouldn't care whether the date is dd-mm-yyyy, mm/dd/yy, mm/dd/yyyy, m-d-yy, etc. Just make sure you pass it a date value that is formatted compliant to the server's localization. If necessary use VB's CDate(strDateValue) before passing strDateValue to the function.
You can also easily modify this function to do the same for Time values, except you use Hour, Minute, and Second VB functions, and delimit with a colon (:) instead of a dash (-).
Hope this helps!
Function funcMySqlDate(dtmChangeDate)
'CONVERTS LOCALIZED DATE FORMAT (for example: m/d/yy) TO MySQL FORMAT (yyyy-mm-dd)
Dim strTempYear, strTempMonth, strTempDay
strTempYear = Year(dtmChangeDate)
strTempMonth = Month(dtmChangeDate)
strTempDay = Day(dtmChangeDate)
if Len(strTempYear) = 2 then 'Y2K TEST - 1938-2037 - ADJUST AS NECESSARY
if strTempYear >= 38 then
strTempYear = "19" & strTempYear
else
strTempYear = "20" & strTempYear
end if
end if
if strTempMonth < 10 then strTempMonth = "0" & strTempMonth
if strTempDay < 10 then strTempDay = "0" & strTempDay
funcMySqlDate = strTempYear & "-" & strTempMonth & "-" & strTempDay
End Function
Posted by Benjamin Zagel on August 5 2004 12:44pm [Delete] [Edit]
To find out the last day of a month use:
SELECT (DATE_FORMAT('2004-01-20' ,'%Y-%m-01') - INTERVAL 1 DAY) + INTERVAL 1 MONTH;
It tooks me a few time to have this idea, but it works. If you want to have the first day of a month use:
SELECT DATE_FORMAT('2004-01-20' ,'%Y-%m-01');
To find out the first day of a month was my first development step, then it was easy to extract the last day of a month. It is usefull for accounting for services where I need this solution.
Greetings
Posted by Mark Stafford on August 6 2004 5:26pm [Delete] [Edit]
I see the use for both, but I find this layout more useful as a reference tool:
+--------------+----------+--------------------+
| metric | variant | result |
+--------------+----------+--------------------+
| microseconds | %f | 000000..999999 |
| seconds | %s or %S | 00..59 |
| minutes | %i | 00..59 |
| hours | %H | 00...23 |
| | %h or %I | 00...12 |
| | %k | 0...23 |
| | %l | 1...12 |
| day | %a | Sun...Sat |
| | %D | 1st, 2nd, 3rd |
| | %d | 0.31 |
| | %e | 0..31 |
| | %j | 001...366 |
| | %W | Sunday...Sat |
| | %w | 0...6 |
| week | %U | 00...53 per Sun |
| | %u | 00...53 per Mon |
| * | %V | 01...53 per Sun |
| * | %v | 01...53 per Mon |
| month | %b | Jan...Dec |
| | %c | 0...12 |
| | %M | January...December |
| | %m | 00...12 |
| year | %Y | 1999 |
| | %y | 99 |
| * | %X | 1999 |
| * | %x | 99 |
| time | %r | 01:31:12 pm |
| | | %T | 01:31:12 pm |
| | %p | AM or PM |
| Percent sign | %% | % |
+--------------+----------+--------------------+
Posted by M l on August 7 2004 6:53pm [Delete] [Edit]
Select records that are older than X days from the current date where sent_time is a Timestamp datatype field.
select ID from MESSAGE where SENT_TIME < (CURDATE() - INTERVAL 5 DAY);
Posted by R C on August 24 2004 7:21pm [Delete] [Edit]
If you do not have 4.xx yet here is a simple way to get the last day of the month. You can replace the current date with a var to find the last day of any month.
SELECT
SUBDATE( ADDDATE( CURDATE(), INTERVAL 1 MONTH), INTERVAL DAYOFMONTH( CURDATE() ) DAY) AS LAST_DAY_MONTH
seems to work well .
Posted by John Takacs on September 8 2004 10:39pm [Delete] [Edit]
I'm not sure if this is mentioned above, however, none of the STR_TO_DATE() functions works in MySQL version 4.0.18.
So that there is no misunderstanding, the following SQL copied from the above STR_TO_DATE() section:
SELECT STR_TO_DATE('00/00/0000', '%m/%d/%Y');
returns the following error:
ERROR 1064: You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near '('00/00/0000', '%m/%d/%Y')' at line 1
I copied and pasted all of the examples for STR_TO_DATE and none work.
Posted by Martin Algesten on September 9 2004 2:00pm [Delete] [Edit]
>Several times i have come to a followng date/time problem:
>In the table i am storing both date and time information in the
>datetime column. Querying, I want to receive COUNTed results
>grouped by date, and not date and time. I came to the easy
>solution:
I needed a query for a more general case to do time based reporting on arbitrary big "slices" of timestamped data.
My table has a column 'timestamp' which is of type 'datetime'.
The following makes '120' second big slices
select from_unixtime(unix_timestamp(timestamp) - unix_timestamp(timestamp) % 120) as slice, ... group by slice;
Posted by David Berry on September 17 2004 7:08pm [Delete] [Edit]
I wanted to find the start date (Sunday) and the end date (Saturday) for any given week when all I had to go from is an arbitrary date (more precisely, the current date). Since MySQL registers Sunday as 1, and Saturday as 7, if you wish to adjust the start and end points on a week, you'll have to modify the following function calls appropriately, and change the integers, or (as I have done) use variables:
set @someday = curdate();
set @weekstart = 1; // Sunday
set @weekend = 7; // Saturday
end of week:
select date_add(@someday, interval @weekend-dayofweek(@someday) day);
beginning of week:
select date_sub(@someday, interval dayofweek(@someday)-@weekstart day);
Of course, I use these functions in a more complex query that filters select results from a table with a "datetime" field. This allows me to focus on weekly data. A very neat thing is being able to replace 'curdate()' with a date at (theoretically) any point in time on the Gregorian calendar.
Posted by Jeffrey Friedl on October 31 2004 9:05am [Delete] [Edit]
The value returned by
UNIX_TIMESTAMP(NOW())
can be quite unintuitive during the last hour of daylight-saving time in the fall, as it can return a timestamp that's an hour ahead of the current time. (The docs indicate that this may be "fixed" from 4.1.3, but I have not tested.)
This is because CST-related information is lost during the conversion by NOW() from the current time to a string. When presented a date string like "2004-10-31 01:52:37" which names a time that happened twice (once during daylight-saving time, and again an hour later in standard time), it doesn't know which you intend it to be interpreted as.
The docs indicate that from 4.1.3, it uses the timezone in effect at the time of the SELECT, which implies that
FROM_UNIXTIME("2004-10-31 01:52:37")
returns a different value depending on whether you are currently under daylight-saving time or not. With 4.1.2 and before, it seems to always use standard time, and hence the one-hour "error" (which is not really an error, but damn unintuitive that UNIX_TIMESTAMP(NOW()) does not return the UNIX_TIMESTAMP for now.
Note that UNIX_TIMESTAMP() without args does return the proper unix timestamp for the current time.
Posted by Shamun toha on December 18 2004 10:45am [Delete] [Edit]
If you have a table1 , and (fields date which is varchar(100)
you can also convert it as date type look the following example
mysql> select str_to_date(date,'%d/%m/%Y') as Mydate from table1 order by Mydate DESC;
+------------+
| Mydate |
+------------+
| 2004-12-16 |
| 2004-12-15 |
| 2004-12-02 |
| 2004-12-02 |
| 2004-11-01 |
| 2004-10-29 |
| 2004-10-12 |
| 2004-10-07 |
| 2004-09-12 |
| 2004-08-19 |
| 2004-08-13 |
| 2004-08-09 |
| 2004-08-04 |
| 2004-07-30 |
| 2004-07-26 |
| 2004-07-20 |
| 2004-07-16 |
| 2004-07-14 |
+------------+
18 rows in set (0.00 sec)
mysql>
Posted by John Romano on January 26 2005 10:06pm [Delete] [Edit]
If you need to EXTRACT the QUARTER prior to v5.0 try CEILING(EXTRACT(MONTH FROM date)/3)
Posted by Robert Christiaanse on January 27 2005 2:18pm [Delete] [Edit]
CALCULATING A DATE USING A WEEK NUMBER
If you want to calculate the date having a year, a day of the week and a weeknumber (Let's say Thursday of week number 4 in 2005), you can calculate it like this:
SELECT DATE_ADD('2005-01-04', INTERVAL ((4-1)*7+(4 - DATE_FORMAT('2005-01-04','%w'))) DAY);
In PHP it would be something like this (when weeks start on Monday):
$Days=array('xx','ma','di','wo','do','vr','za','zo');
$DayOfWeek=array_search($aDay,$Days); //get day of week (1=Monday)
$Year=2005;
$Week=4;
$query = "SELECT DATE_ADD('".$Year."-01-04', INTERVAL ((".$Week."-1)*7+(".$DayOfWeek." - DATE_FORMAT('".$Year."-01-04','%w'))) DAY)";
January 4th is chosen as a base, because it is always in week number 1. ( January 1st is not necessarely in week1! )
You can test it with this:
//connect to your database first
$Year=2005;
for ($weeknr=0; $weeknr <= 53; $weeknr++)
{
for ($day=1; $day <= 7; $day++)
{
$query = "
SELECT
DATE_ADD('".$Year."-01-04',
INTERVAL ((".$weeknr."-1)*7+
(".$day." - DATE_FORMAT('".$Year."-01-04','%w'))) DAY)
";
$result= mysql_query($query);
if ($result)
{
$row = mysql_fetch_row($result);
echo "year=$Year weekno=$weeknr day=$day : ".$row[0].'
';
}
else
echo 'empty result set
'.EOL;
}
}
?>
Posted by Ralph Noordanus on February 18 2005 12:23pm [Delete] [Edit]
+---------------------+---------------------+
| date1 | NOW() |
+---------------------+---------------------+
| 2005-03-17 16:00:00 | 2005-02-18 13:07:29 |
+---------------------+---------------------+
If you're looking for an SQL query that returns the number of days, hours and minutes between date1 and now:
SELECT CONCAT(DAYOFYEAR(date1)-DAYOFYEAR(NOW()),' days ', DATE_FORMAT(ADDTIME("2000-00-00 00:00:00",SEC_TO_TIME(TIME_TO_SEC(date1)-TIME_TO_SEC(NOW()))),'%k hours and %i minutes')) AS time FROM time_table;
+---------------------------------+
| time |
+---------------------------------+
| 27 days 2 hours and 52 minutes |
+---------------------------------+
Posted by Luke Burgess on October 15 2006 5:56am [Delete] [Edit]
There doesn't appear to be an official way of selecting * from a table where eg 'date is january 2005'. So far i've found 8 different ways!!
1. where date like '2005-01-%'
2. where DATE_FORMAT(date,'%Y-%m')='2005-01'
3. where EXTRACT(YEAR_MONTH FROM date)='200501'
4. where YEAR(date)='2005' and MONTH(date)='1'
5. where substring(date,1,7)='2005-01'
6. where date between '2005-01-01' and '2005-01-31'
7. where date >= '2005-01-01' and date <= '2005-01-31'
8. where date IN('2005-01-01', '2005-01-02', '2005-01-03', '2005-01-04', '2005-01-05', '2005-01-06', '2005-01-07', '2005-01-08', '2005-01-09', '2005-01-10', '2005-01-11', '2005-01-12', '2005-01-13', '2005-01-14', '2005-01-15', '2005-01-16', '2005-01-17', '2005-01-18', '2005-01-19', '2005-01-20', '2005-01-21', '2005-01-22', '2005-01-23', '2005-01-24', '2005-01-25', '2005-01-26', '2005-01-27', '2005-01-28', '2005-01-29', '2005-01-30', '2005-01-31')
Posted by Josh Hayden on March 20 2005 2:14am [Delete] [Edit]
I needed a query that would delete all rows that were created over an hour ago. Here's what I used:
To insert the row:
INSERT INTO `table_name` ( `time_col`) VALUES (NOW());
To delete the rows created over an hour ago:
DELETE FROM `table_name` WHERE `time_col` < ADDDATE(NOW(), INTERVAL -1HOUR);
Posted by Erin Quick-Laughlin on March 29 2005 12:49am [Delete] [Edit]
To take Cherice Scharf's vb example one step further, here's the conversion from vb's now format of 'MM/DD/YY HH:MM:SS PM' to 'YYYY-MM-DD HH:MM:SS' for easy insertion to the datetime field:
Function ConvertInputDateTime(varDateTime)
If (Len(Trim(varDateTime)) > 0) Then
DateTimeArray=Split(CStr(varDateTime)," ")
varDate = DateTimeArray(0)
varTime = DateTimeArray(1)
varAMPM = DateTimeArray(2)
If (Len(Trim(varDate)) > 0) Then
DateArray=Split(CStr(varDate),"/")
IF Len(Trim(DateArray(0))) < 2 Then
DateArray(0) = "0" & DateArray(0)
End If
If Len(Trim(DateArray(1))) < 2 Then
DateArray(1) = "0" & DateArray(1)
End If
If Len(Trim(DateArray(2))) < 4 Then
DateArray(2) = "20" & DateArray(2)
End If
varDate = DateArray(2) & "-" & DateArray(0) & "-" & DateArray(1)
End If
If (Len(Trim(varDate)) > 0) Then
TimeArray=Split(CStr(varTime),":")
If Trim(varAMPM) = "PM" Then
TimeArray(0) = CStr(TimeArray(0) + 12)
End If
If Len(Trim(TimeArray(0))) < 2 Then
TimeArray(0) = "0" & TimeArray(0)
End If
varTime = TimeArray(0) & ":" & TimeArray(1) & ":" & TimeArray(2)
End If
varDateTime = varDate & " " & varTime
End If
ConvertInputDateTime = varDateTime
End Function
Thanks for the starting code Cherice!
Posted by paul adams on April 1 2005 9:30am [Delete] [Edit]
"SELECT id, transactionid, (UNIX_TIMESTAMP(now()) - UNIX_TIMESTAMP(date)) AS date , sucessful, amount FROM Transaction where sucessful = 1"
to work out the difference between when it was placed to now.
Posted by santi bari on June 10 2005 2:49pm [Delete] [Edit]
GENERATE missing days on a table with date gaps
=====================================
If you want to bring visits per day to your site and you have a table
wich
is storing the hits, in a way similar to this...
+--------------+--------------------------+
| date | IP
+--------------+--------------------------+
|2004-8-3 | 123.123.124.155
|2004-8-3 | 123.123.124.145
|2004-8-5 | 123.123.124.145
+--------------+--------------------------+
You may want to draw a chart and retrieve all the hits per day. The
problem is that DAYS WITHOUT HITS WON'T APPEAR. And you won't be able
to
display the info of '0 hits'.
One solution to this which is easy to code and clean, is to create and
have in your database, a table named 'calendar' with all the days from
today till some years from now (let's say, till 2034). The table
should
look something like this:
+----------+
| date
+----------+
| 2004-1-1
| 2004-1-2
| 2004-1-3
| 2004-1-4
| 2004-1-5
| ...
| etc...
+---------+
Here is a piece of code which will make such table:
mysql_query("CREATE TABLE `calendar` (
`id` int(11) NOT NULL auto_increment,
`date` date NOT NULL default '0000-00-00',
PRIMARY KEY (`id`)
) TYPE=MyISAM; ");
for($i=0;$i<=(365*30);$i++)
mysql_query("INSERT INTO CALENDAR SET date=date_add(now(),INTERVAL
LAST_INSERT_ID() DAY)");
?>
Then all you have to do is perform a LEFT JOIN from this table and
you've
got every day from the period of time you specify. Even those with 0
hits
SELECT calendar.date, count(*)
FROM calendar
LEFT JOIN visits ON calendar.date=visits.date
GROUP BY calendar.date
Posted by Benjamin Gehrels on May 12 2005 1:50am [Delete] [Edit]
Be carefull with the DAYOFYEAR-Function in comparisions, because you will run into a trap every 4 years, when Feburary is a day shorter...
Posted by Labb on May 20 2005 1:24pm [Delete] [Edit]
To Posted by Erin Quick-Laughlin on March 29 2005 2:49am
The much more easier way:
date = "YYYY/MM/DD HH-SS-MM"
date = Replace(date, "/", "-")
thats it...
Posted by Juan Antonio on May 23 2005 3:36pm [Delete] [Edit]
age from date of birth compared whith
in this function you can know the age of a person(it works for my). preg 12 is a date in the format show bellow i dont know if it is fast. if you have a recent version you can asign curtime to a variable for get more performance else use php,c++ or another to save it as:
YYYY-MM-DD example: 1997-03-31
left((curtime()-preg12),(CHAR_LENGTH(curtime()-preg12)-4))
another way is:
(TO_DAYS("a - date") - TO_DAYS("birth"))/365
you can replece the curdate for a before date changing curdate to this 20000619 NOT THIS: 2000-06-19 if you have beter way send it to my tanks bye.
Posted by John Anderson on May 25 2005 8:04pm [Delete] [Edit]
To calculate week ending date given an arbitrary date, use the following (assumes Saturday is week end)
SELECT DATE_ADD('2005-05-24', INTERVAL (7 - DAYOFWEEK('2005-05-24')) DAY)
SELECT DATE_ADD(table.column, INTERVAL (7 - DAYOFWEEK(table.column)) DAY)
Posted by Pe3k on June 15 2005 12:51pm [Delete] [Edit]
If U have older version of MySQL you can replace 'TIMEDIFF(time1,time2)' with
'SEC_TO_TIME( (TO_DAYS(time1)*24*3600+TIME_TO_SEC(time1)) - (TO_DAYS(time2)*24*3600+TIME_TO_SEC(time2)) )'
It is completly same. :)
Posted by Daniel Schroeder on July 16 2005 4:58pm [Delete] [Edit]
I had the task to select rows of a table where the date of creation was in the future of a given date.
The problem was there was no date or timestamp-field, but two fields (int), one for month and one for year.
Since I have MySQL-Version prior to 4.1.1, where most of the nice date/time-functions have been added, I had to work out a query that builds and compares dates out of the given values.
Here it is:
SELECT *
FROM your_table
WHERE CONCAT(your_table.field_year,'-',REPEAT(0,2-LENGTH(your_table.field_month)),your_table.field_month,'-','01') >= CONCAT({MIN_YEAR},'-',REPEAT(0,2-LENGTH({MIN_MONTH})),{MIN_MONTH},'-','01')
ORDER BY your_table.field_year,
your_table.field_month;
I noticed an advantage compared to working with timestamps: You are able to work with dates before 1970.
Posted by Oliver Pereira on July 19 2005 1:40pm [Delete] [Edit]
The description of FROM_DAYS(N) - "Given a daynumber N, returns a DATE value" - uses the term "daynumber" without explaining it.
The description of TO_DAYS(date) - "Given a date date, returns a daynumber (the number of days since year 0)" - lower down the page at least tries to explain the term, but unsuccessfully.
There are two problems here. Firstly, there was no year 0 in the Gregorian calendar. Secondly, a number of days has to be counted from a day, not a year. Do they mean the beginning of the (non-existent) year, or the end of the (non-existent) year? Do non-existent years even have beginnings and ends? Someone should amend these descriptions.
Posted by k s on August 12 2005 7:51am [Delete] [Edit]
Here's another query to get the number of months between two dates:
select period_diff(DATE_FORMAT(date1,'%Y%m'),DATE_FORMAT(date2,'%Y%m')) from tablexy
Posted by Bob Terrell on August 22 2005 5:40pm [Delete] [Edit]
Note that there is currently no way to get the 'AM' or 'PM' part of a time-only value using the built-in functions. You must first convert it to a datetime and then use DATE_FORMAT('%p') or perform your own calculations in your app.
Posted by Deron Meranda on August 31 2005 8:33pm [Delete] [Edit]
On transactional consistency...Concerning the functions which use the real current time, such as NOW(), the manual says "Functions that return the current date or time each are evaluated only once per query at the start of query execution."
Note though that this does not apply across entire transactions, as you may expect. Thus a transaction like:
START TRANSACTION;
INSERT INTO EVENTS VALUES (NOW(), 'A');
INSERT INTO EVENTS VALUES (NOW(), 'B');
COMMIT;
will result in potentially two different times being recorded for the two records.
Posted by cameron green on September 16 2005 6:13am [Delete] [Edit]
If you need the type to be dynamically taken from a table (that is where you have "year", "day", "month" etc as a column in the table), here is the best way I could work out to do it. Expand as necessary :
SELECT set_date, unit_period, unit_multiplier, CASE WHEN unit_period = "month" THEN DATE_SUB(set_date, INTERVAL unit_multiplier MONTH) WHEN unit_period = "week" THEN DATE_SUB(set_date, INTERVAL (unit_multiplier * 7) DAY) WHEN unit_period = "year" THEN DATE_SUB(set_date, INTERVAL unit_multiplier YEAR) ELSE DATE_SUB(set_date, INTERVAL unit_multiplier DAY) END FROM dates_table;
Posted by Andrzej Salamon on September 22 2005 1:27pm [Delete] [Edit]
Returns all rows from actual month to given @months. eg. if you want get all rows in:
5 months from now:
(2005-09) - 5 = (2005-04)
all rows from 2005-04-01 to 2005-04-30
2 months from now
(2005-09) - 2 = (2005-07)
all rows from 2005-07-01 to 2005-07-31
SQL variables, can be PHP variables like $months,$nextMonth,$begin,$end
set @months = 1; #change only this value(months back from actual month)
set @nextMonth = @months+1;
set @begin = FROM_DAYS(TO_DAYS(LAST_DAY( DATE_SUB(NOW(), INTERVAL @nextMonth MONTH )))+1);
set @end = FROM_DAYS(TO_DAYS(LAST_DAY( DATE_SUB(NOW(), INTERVAL @months MONTH )))+1);
SELECT cols_u_want FROM tbl_u_want
WHERE timestampCol
BETWEEN @begin AND @end
It`s my solution. If U have Your own please email me.
Sorry for my english :)
Posted by Bryan Donovan on November 14 2005 9:22pm [Delete] [Edit]
I'm not sure if this is the best way, but it works to get the date of the Monday of the week of a date. For example, if you have a datetime column called starttime in a table called test_events, you could select the distinct Mondays from your table as follows:
SELECT DISTINCT(STR_TO_DATE(CONCAT(YEARWEEK(starttime),'1'),'%x%v%w'))
FROM test_events;
Hopefully there is a better way..
Posted by Rodolfo Maripan on November 29 2005 3:52pm [Delete] [Edit]
I was using mysql v4 and the date was in a varchar data type, in order to change the data type in mysql v5 i use the following code:
update ssd_escondida.tactual_sag4 set ssd_escondida.tactual_sag4.Fecha=str_to_date(ssd_escondida.tactual_sag4.Fecha2,'%e/%m/%Y');
where:
ssd_escondida: database
tactual_sag4:is a table
Fecha: is a date type
Fecha2:is a varchar which contains a date, but is from 01/01/2005 to 04/01/2005 (with a zero at the begining)
why i used %e instead of %d??? the answer is very simple, there is a problem with de help about str_to_date:
%d: represents the days, but from 0 to 31 and...
%e: represents the days, but from 00 to 31.
that's the reason why we cannot use: str_to_date('00/00/0000',%d/%m/%Y), we must use str_to_date('00/00/0000','%e/%m/%Y')
Another way in order to change a string like: 00/00/0000 to a date is to use: str_to_date('00/00/0000','0%d/%m/%Y')
Posted by Regina Mullen on December 3 2005 10:25pm [Delete] [Edit]
Simple method of converting dates from any of
MM-DD-YYYY
MM/DD/YYYY
MM.DD.YYYY
(oldDate) to YYYY-MM-DD (addDate). Load date in as text and convert in one go using:
update table set addDate = CONCAT_WS('-', RIGHT( oldDate,4), LEFT( oldDate,2), SUBSTRING( oldDate,4,2))
Caveat: make sure your text input doesn't have spaces.
Posted by Hyper Hacker on December 26 2005 10:54pm [Delete] [Edit]
In MySQL 4.0, and possibly others, UNIX_TIMESTAMP() doesn't work with dates before 1970. This query does the same, and works with any date from from Fri, 13 Dec 1901 20:45:54 to Tue, 19 Jan 2038 03:14:07. 'date' is the name of the DATETIME column you need a timestamp of.
SELECT (((TO_DAYS(date) * 86400) + TIME_TO_SEC(date)) - (TO_DAYS("1970-01-01") * 86400)) AS timestamp
If you're using PHP, note that date() accounts for DST and thus may appear to return incorrect results; also, don't forget to escape the quotes around 1970-01-01.
Posted by Noel Athaide on December 27 2005 8:23am [Delete] [Edit]
Keyphrases: Birthday reminder, select dates between
This might be useful. If you have a database containing 'name' and 'birthday' (as columns) then the following query will list the birthdays in the next 15 days. (16 to be more precise :-))
What I found unique about this problem is that the YEAR (of birth) will always be different and hence one cannot simply use a query like :
| SELECT * FROM `friends` WHERE
| `birthday` >= CURDATE()
| AND
| `birthday` <= ADDDATE(CURDATE(), INTERVAL 15 DAY);
because it would take the year into consideration.
The correct way, I believe, to get the desired result is as follows:
| SELECT * FROM `friends` WHERE (
| EXTRACT(MONTH FROM `birthday` ) = EXTRACT(MONTH FROM
| CURDATE())
| AND
| DAYOFMONTH(`birthday`) >= DAYOFMONTH(CURDATE())
| AND
| DAYOFMONTH(`birthday`) <= (DAYOFMONTH(CURDATE()) + 15)
| )
|
| OR (
| EXTRACT(MONTH FROM `birthday`) = EXTRACT(MONTH FROM
| ADDDATE(CURDATE(), INTERVAL 15 DAY))
| AND
| DAYOFMONTH(`birthday`) <= DAYOFMONTH(ADDDATE(CURDATE(),
| INTERVAL 15 DAY))
| )
The logic should be clear from the query itself. Note that in one place I use numerical addition (DAYOFMONTH(CURDATE()) + 15) while lower down I use the ADDDATE function. This distinction is important.
Would be happy if someone could refine the above method.
- Noel Athaide.
PS: Put this into a script and crontab it...and you have a simple Birthday reminder :-)
Posted by [name withheld] on January 12 2006 11:51pm [Delete] [Edit]
the birthday-reminder doesn't work the way it should be. I found the bug and fixed it. this is a working example:
SELECT user_birthdate,user_name,user_id , EXTRACT(MONTH FROM `user_birthdate` ) month, EXTRACT(DAY FROM `user_birthdate` ) day
FROM ".$db_prefix."users
WHERE
(
EXTRACT(MONTH FROM `user_birthdate` ) = EXTRACT(MONTH FROM CURDATE())
AND
DAYOFMONTH(`user_birthdate`) > DAYOFMONTH(CURDATE())
AND
DAYOFMONTH(`user_birthdate`) <= (DAYOFMONTH(CURDATE()) + 15)
)
OR
(
EXTRACT(MONTH FROM ADDDATE(CURDATE(), INTERVAL 15 DAY))<>EXTRACT(MONTH FROM CURDATE())
AND
EXTRACT(MONTH FROM `user_birthdate`) = EXTRACT(MONTH FROM ADDDATE(CURDATE(), INTERVAL 15 DAY))
AND
DAYOFMONTH(`user_birthdate`) <= DAYOFMONTH(ADDDATE(CURDATE(), INTERVAL 15 DAY))
)
ORDER BY month, day, user_id ASC
sorry for the strange name, but this is the way my table are named...
hope you like it
Posted by Stijn Tas on January 23 2006 4:07pm [Delete] [Edit]
I'm using this query for a birthday-reminder:
SELECT `geb_Geboorte`
FROM `gebruikers`
WHERE
DAYOFYEAR( curdate( ) ) <= dayofyear( `geb_Geboorte` )
AND
DAYOFYEAR( curdate( ) ) +15 >= dayofyear( `geb_Geboorte` );
I change the year of birthday to the current year.
Sorry for the dutch tablenames.
Posted by John L. on January 25 2006 3:56pm [Delete] [Edit]
It took me a bit of time to find how to select data based on time periods (such as for quarterly or yearly reports). You can use group by month(DateTypeColumn).
example- to find periodic totals:
SELECT [Year|Quarter|Month|Day](date) as Period,shipcountry,shipstate,shipcity,sum(products),sum(shipping),sum(tax)
FROM products NATURAL JOIN shipping NATURAL JOIN tax
GROUP BY Period,shipcountry,shipstate,shipcity
more here-
http://dev.mysql.com/doc/refman/5.0/en/date-and-time-functions.html
I suppose you could alter the start of quarterly periods by doing some arithmetic on the (date), but you might have to do some conversions.
Posted by [name withheld] on March 6 2006 7:32pm [Delete] [Edit]
Time arithmetic using CURTIME() is quite willing to type everything into integers rather than adding and subtracting seconds. For example, where log_time is a TIME column;
SELECT log_time AS Time FROM call_log
WHERE log_time >= (CURTIME( ) - 60 );
will fetch all results from the last 60 seconds. However,
SELECT log_time AS Time FROM call_log
WHERE log_time >= (CURTIME( ) - 900 );
will fetch all results from the last 9 minutes. 900 is interpreted, not as 900 seconds (15 minutes), but as 9:00. An hour is 10000 (1:00:00), not 3600 (36:00).
If you want to add seconds, use something like the following (for the last hour);
SELECT log_time AS Time FROM call_log
WHERE log_time >= (CURTIME( ) - SEC_TO_TIME(3600) );
Posted by Issac Goldstand on March 9 2006 12:34am [Delete] [Edit]
If you have a column of date values and you want to compare the day portion of them with today's date, taking in mind shorter months which might not contain all the dates in your set (example, billing systems or anything else which needs to run on each record or recordset on a given day of the month), you can try one of these (replacing '2002-04-30' with the date field you're comparing):
SELECT DATE_FORMAT(CURDATE()-INTERVAL 1 MONTH, CONCAT('%Y-%m-',DAY('2002-04-30')))+INTERVAL 1 MONTH;
This tends to "round down" on missing days - for example for dates ending in 30, this will translate to feb 28 (in february).
Posted by Marko Kruustük on April 5 2006 2:19pm [Delete] [Edit]
In reply to "David Berry on September 17 2004 9:08pm"
Problem: To find week start and end date with user specified start of the week day and user specified date for which the week is to be found.
David's solution does not work with user specified week start and end. It only works with normal week which is 1 and 7 as start and end correspondingly.
As I needed different starting day for week than Sunday or Monday for timesheet calculations, I had to come up with working solution:
...
date_sub(t.date, interval if(dayofweek(t.date)-$weekStartingDay >= 0, dayofweek(t.date)-$weekStartingDay, dayofweek(t.date)-$weekStartingDay+7) day) week_start
...
date_sub(t.date, interval if(dayofweek(t.date)-$weekStartingDay >= 0, dayofweek(t.date)-$weekStartingDay, dayofweek(t.date)-$weekStartingDay+7) - 6 day) week_end
...
This solution works fine for me, at least at the moment till I find some bug in it :)
Posted by [name withheld] on April 14 2006 3:57am [Delete] [Edit]
Use this to find the date of the last Friday. Please let me know if there is a more efficient way of doing this.
select if(DATE_FORMAT(curdate(),'%w')>4,date_sub(curdate(),INTERVAL DATE_FORMAT(curdate(),'%w')-5 DAY),date_sub(curdate(),INTERVAL DATE_FORMAT(curdate(),'%w')+2 DAY))
Posted by Horst Schirmeier on April 17 2006 11:16pm [Delete] [Edit]
Just another example on how to figure out how many days are until some birthdate (in order to do a range query, or get the "next" birthday):
SELECT name, birthday,
IF(DAYOFYEAR(birthday) >= DAYOFYEAR(NOW()),
DAYOFYEAR(birthday) - DAYOFYEAR(NOW()),
DAYOFYEAR(birthday) - DAYOFYEAR(NOW()) +
DAYOFYEAR(CONCAT(YEAR(NOW()),'-12-31')))
AS distance
FROM birthdates;
The + DAYOFYEAR(CONCAT(YEAR(NOW()),'-12-31')) (which is 366 or 365, depending on whether we're in a leap year or not) takes care of the New Year's Eve wrap around.
You could add WHERE distance <= 10 or ORDER BY distance ASC LIMIT 1 at the end of the query, for example.
Posted by Frederick Ducharme on May 9 2006 9:25pm [Delete] [Edit]
A simple way to get the number of month between 2 date :
SELECT PERIOD_DIFF(EXTRACT(YEAR_MONTH FROM mydate1), EXTRACT(YEAR_MONTH FROM mydate2)) AS month_interval
FROM ....
Posted by Dmitry Dimov on June 5 2006 7:07pm [Delete] [Edit]
Here's what I used to get a summary of some value by day of the week:
select date_format(date, "%W") AS `Day of the week`, sum(cost)
from daily_cost
group by `Day of the week`
order by date_format(date, "%w")
Output:
+-----------------+-----------+
| Day of the week | sum(cost) |
+-----------------+-----------+
| Sunday | 271.53 |
| Monday | 310.95 |
| Tuesday | 323.6 |
| Wednesday | 312.45 |
| Thursday | 301.76 |
| Friday | 294.76 |
| Saturday | 255.83 |
+-----------------+-----------+
To order results starting with Monday, change the "order by" expression to
order by (date_format(date, "%w") - 7) % 7
Posted by Jens Hopp on June 6 2006 1:04pm [Delete] [Edit]
LAST_DAY() with MySQL 3.23
Need to show the 1st day of the next month? - and were happy to find LAST_DAY() and just thought about adding one single day to its result? - and then discovered that you need MySQL 4+ for that?
Use this ugly chain of functions to show the 1st day of the next month - in MySQL 3.23:
FROM_DAYS(TO_DAYS(CONCAT(SUBSTRING(PERIOD_ADD(DATE_FORMAT(mydate,"%y%m" ),1),3,4),"01")))
You could subtract one day to simulate LAST_DAY() at all.
Posted by Richard Wolterink on July 10 2006 7:24am [Delete] [Edit]
I made a Stored Function which can covert an ISO 8601 (2006-07-05T13:30:00+02:00) date to a UNIX TIMESTAMP of the corresponding UTC or GMT datetime, so you can compare timestamps from different timezones with eachother. Hope this can help someone.
CREATE FUNCTION ISO8601TOUNIXTIMESTAMP (iso varchar(25))
RETURNS INTEGER(15)
DETERMINISTIC
BEGIN
DECLARE CONVTIME INTEGER(11);
SET CONVTIME = (SUBSTRING(iso,21,2) * 60) + SUBSTRING(iso,24,2);
IF SUBSTRING(iso,20,1) = '+' THEN
SET CONVTIME = 0 - CONVTIME;
END IF;
RETURN UNIX_TIMESTAMP(DATE_ADD(STR_TO_DATE(CONCAT(SUBSTRING(iso,1,10),' ',SUBSTRING(iso,12,8)),'%Y-%m-%d %H:%i:%s'), INTERVAL CONVTIME MINUTE));
END
Posted by Azizur Rahman on July 12 2006 10:08am [Delete] [Edit]
To get the first day of the current month:
SELECT ((PERIOD_ADD(EXTRACT(YEAR_MONTH FROM CURDATE()),0)*100)+1) as FirstDayOfTheMonth;
This will give you the first day of the month.
mysql> SELECT ((PERIOD_ADD(EXTRACT(YEAR_MONTH FROM CURDATE()),0)*100)+1) as FirstDayOfTheMonth;
+--------------------+
| FirstDayOfTheMonth |
+--------------------+
| 20060701 |
+--------------------+
1 row in set
To get the last day of the current month:
SELECT (SUBDATE(ADDDATE(CURDATE(),INTERVAL 1 MONTH),INTERVAL DAYOFMONTH(CURDATE())DAY)) AS LastDayOfTheMonth;
This will give you the first day of the month.
mysql> SELECT (SUBDATE(ADDDATE(CURDATE(),INTERVAL 1 MONTH),INTERVAL DAYOFMONTH(CURDATE())DAY)) AS LastDayOfTheMonth;
+-------------------+
| LastDayOfTheMonth |
+-------------------+
| 2006-07-31 |
+-------------------+
1 row in set
Hope this helps!
Posted by Jordan Gray on August 1 2006 11:17am [Delete] [Edit]
This function will return the difference between two dates as a string, in the format "Y year[s], M month[s], D day[s]" (pluralisation as appropriate):
|CREATE FUNCTION getDateDifferenceString(date1 DATE, date2 DATE) RETURNS VARCHAR(30)
| RETURN CONCAT(
| /* Years between */
| @years := TIMESTAMPDIFF(YEAR, date1, date2),
| IF (@years = 1, ' year, ', ' years, '),
| /* Months between */
| @months := TIMESTAMPDIFF(MONTH, DATE_ADD(date1, INTERVAL @years YEAR), date2),
| IF (@months = 1, ' month, ', ' months, '),
| /* Days between */
| @days := TIMESTAMPDIFF(DAY, DATE_ADD(date1, INTERVAL @years * 12 + @months MONTH), date2),
| IF (@days = 1, ' day', ' days')
| )
|;
It took a while to work this one out, so I hope this might save someone else the bother.
Posted by Daevid Vincent on August 4 2006 7:14am [Delete] [Edit]
I'm not sure why Horst Schirmeier did that very complex birthdate equation. Seems to me you could just do:
SET @DOYNOW = DAYOFYEAR(CURDATE());
SELECT (DAYOFYEAR(birthdate) - @DOYNOW) AS birthdays, birthdate, @DOYNOW, CURDATE()
FROM users
WHERE birthdate IS NOT NULL;
then if birthdays == 0, it's that persons birthday, otherwise you know if the birthday is in the future by how many days, or if you missed it and how many beers you owe them...
(although the missed/negative days seems to be off)
+-----------+------------+---------+------------+
| birthdays | birthdate | @DOYNOW | CURDATE() |
+-----------+------------+---------+------------+
| 83 | 1969-10-26 | 216 | 2006-08-04 |
| 3 | 1981-08-07 | 216 | 2006-08-04 |
| -1 | 1972-08-02 | 216 | 2006-08-04 |
| 0 | 1946-08-04 | 216 | 2006-08-04 |
| -151 | 1976-03-05 | 216 | 2006-08-04 |
+-----------+------------+---------+------------+
Shouldn't that -1 be -2 ?
Am I missing something obvious?
If I do "SELECT DATEDIFF('2006-08-01', CURDATE());" I get -2 as I expect.
So, I guess the real solution is to use this:
SET @YEAR = CONCAT(EXTRACT(YEAR FROM CURDATE()),'-');
SELECT DATEDIFF(CONCAT(@YEAR, DATE_FORMAT(birthdate, '%m-%d')), CURDATE()) AS birthdays, birthdate, CURDATE()
FROM users
WHERE birthdate IS NOT NULL;
+-----------+------------+------------+
| birthdays | birthdate | CURDATE() |
+-----------+------------+------------+
| 83 | 1969-10-26 | 2006-08-04 |
| 3 | 1981-08-07 | 2006-08-04 |
| -2 | 1972-08-02 | 2006-08-04 |
| 0 | 1946-08-04 | 2006-08-04 |
| -152 | 1976-03-05 | 2006-08-04 |
+-----------+------------+------------+
By the way, if you're using PHP or some other scripting language, you can get rid of the @YEAR stuff and just do:
DATEDIFF(DATE_FORMAT(birthdate, '".date('Y')."-%m-%d'), CURDATE()) AS birthdays
Posted by Arturas D. on August 18 2006 11:11am [Delete] [Edit]
Keyphrases: Birthday reminder
This is another query for the birthday remainder :
| SELECT * FROM `users`
| WHERE
| (
| DAYOFYEAR( NOW() ) > DAYOFYEAR( DATE_SUB(birthdate,INTERVAL 7 DAY) )
| AND
| DAYOFYEAR( NOW() ) <= DAYOFYEAR( DATE_SUB(birthdate,INTERVAL 7 DAY) )+7
| )
| OR
| (
| DAYOFYEAR( NOW() ) > DAYOFYEAR( birthdate )-7
| AND
| DAYOFYEAR( NOW() ) <= DAYOFYEAR( birthdate )
| );
Posted by jeremy levine on August 22 2006 7:18pm [Delete] [Edit]
Get the first day and/or last day of the current year.
This is the first day of the year ( simple )
SELECT MAKEDATE( EXTRACT(YEAR FROM CURDATE()),1);
This is the last day ( not you can not just replace the 1 with a 365 , some years you need a 366)
SELECT STR_TO_DATE(CONCAT(12,31,EXTRACT(YEAR FROM CURDATE())), '%m%d%Y') ;
Posted by Dave Green on September 14 2006 9:51pm [Delete] [Edit]
SERIAL DATES
------------
to convert dates stored as a double (Dateserial as used by microsoft etc i.e. 38883.8941421412. The whole number is the number of days since either 31/12/1899 or 01/01/1900, the fraction being the proportion of 1 day) into a dd/mm/yyyy hh:mm format:
note - MySQL requires the date taken from 31/12/1899, and even then the addition of number of days is still out by 1 because MySQL like Excel and other programs incorrectly assumes that the year 1900 was a leap year, when it wasn't for some reason.
The SQL to get the correct date is:-
ADDDATE(ADDDATE('1899-12-31 00:00',
The fraction of the time can be multiplied by the number of seconds in a day (84,600) and then added to the date as a number of seconds to get the time as well, so for a datetime the SQL is:-
ADDDATE(ADDDATE(ADDDATE('1899-12-31 00:00',
Sorry is this is a bit obvious, it just took me a while to find all this out. Hope it helps.
Posted by Erel Segal on November 1 2006 4:53am [Delete] [Edit]
Note that the order of arguments in TIMEDIFF is opposite than in TIMESTAMPDIFF, so:
TIMESTAMPDIFF(SECOND,expr1,expr2) = TIME_TO_SEC(TIMEDIFF(expr2,expr1))
Posted by Amit Kondhare on November 9 2006 7:52am [Delete] [Edit]
No ready made function is provided for validate date
This function work
(you can take what ever size you want in varchar(1-1024) )
CREATE FUNCTION IsDate (sIn varchar(1024)) RETURNS INT
BEGIN
declare tp int;
if length(date(sIn)) is not null then
set tp = 0;
else
set tp = 1;
end if;
RETURN tp;
END
If you find any bug for this please post it here as this is not complete soluction as date respond are not known
I will try to solve this
Posted by Ron A. on November 14 2006 2:39pm [Delete] [Edit]
Get date for first day of current week if first day of week is monday (SWEDEN, FRANCE, etc):
MONDAY
select date_sub(curdate(),INTERVAL WEEKDAY(curdate()) -0 DAY)
TUESDAY
select date_sub(curdate(),INTERVAL WEEKDAY(curdate()) -1 DAY)
AND SO ON...
Posted by Antonio Angelo on January 17 2007 2:12pm [Delete] [Edit]
The ISO 8601 week number is defined as the number of the week containing the first Thursday.
With this definition, the ISO week number corresponds to WEEK(date, 3) .
The following returns 1 for the week between 2003-12-29 and 2004-01-04:
| SELECT
| WEEK('2003-12-29', 3),
| WEEK('2004-01-04', 3)
Posted by Martin Minka on January 25 2007 5:23pm [Delete] [Edit]
I created this function to calculate "working day" difference of two dates. If you have table with list of holidays you may uncomment part in this function to exclude days of holidays also.
DELIMITER $$
DROP FUNCTION IF EXISTS `workdaydiff`$$
CREATE DEFINER=`root`@`%` FUNCTION `workdaydiff`(b date, a date) RETURNS int(11)
DETERMINISTIC
COMMENT 'working day difference for 2 dates'
BEGIN
DECLARE freedays int;
SET freedays = 0;
SET @x = DATEDIFF(b, a);
IF @x<0 THEN
SET @m = a;
SET a = b;
SET b = @m;
SET @m = -1;
ELSE
SET @m = 1;
END IF;
SET @x = abs(@x) + 1;
/* days in first week */
SET @w1 = WEEKDAY(a)+1;
SET @wx1 = 8-@w1;
IF @w1>5 THEN
SET @w1 = 0;
ELSE
SET @w1 = 6-@w1;
END IF;
/* days in last week */
SET @wx2 = WEEKDAY(b)+1;
SET @w2 = @wx2;
IF @w2>5 THEN
SET @w2 = 5;
END IF;
/* summary */
SET @weeks = (@x-@wx1-@wx2)/7;
SET @noweekends = (@weeks*5)+@w1+@w2;
/* Uncoment this if you want exclude also hollidays
SELECT count(*) INTO freedays FROM holliday WHERE d_day BETWEEN a AND b AND WEEKDAY(d_day)<5;
*/
SET @result = @noweekends-freedays;
RETURN @result*@m;
END$$
DELIMITER ;
Posted by Jemma Hussein on January 31 2007 3:28pm [Delete] [Edit]
If you want to select the time difference between two datetime columns and the fields may contain datetimes that are on different days, you can use the following if statement:
SELECT IF(TIME_TO_SEC(last_date)>=TIME_TO_SEC(first_date),
TIME_TO_SEC(last_date)-TIME_TO_SEC(first_date),
86400+(TIME_TO_SEC(last_date)-TIME_TO_SEC(first_date)))
FROM table;
This will return the time between the last_date and the first date, taking into account the values where first_date and last_date are on different days.
Posted by Will Jaspers on May 2 2007 3:58pm [Delete] [Edit]
NOTE: DateFormat cannot be used to format a TimeDiff calculation.
Example:
SELECT DATE_FORMAT(TIMEDIFF(`appointment_start`,`appointment_end`),'%H:%i:%s')) AS duration FROM appointments;
Correct Syntax:
SELECT TIMEDIFF(`appointment_start`,`appointment_end`) AS duration FROM appointments;
(Tested on MySQL 4.1.20)
Posted by [name withheld] on May 31 2007 5:11pm [Delete] [Edit]
My pick on birthdays remainders :
select date_format( date, "%d/%m" ), DAYOFYEAR( CURDATE( ) ), DAYOFYEAR( date )
from table
where DAYOFYEAR( date ) between DAYOFYEAR( CURDATE( ) ) - 15 and DAYOFYEAR( CURDATE( ) ) + 15
order by date_format( date, "%d/%m/%Y" )
Gabriel Reguly http://ppgr.com.br
Posted by Imran Chaudhry on June 11 2007 10:53am [Delete] [Edit]
As mentioned above STR_TO_DATE() is available as of MySQL 4.1.1.
This function can be useful if you are grouping rows by Week of Year and then want to produce a table with "Week Commencing" as the points on your X-axis.
So what do you do if you're codeshop is using pre-4.1?
Here's what I did. I have a table of events happening on a datetime. I wanted an event count by week with the date of the start of the week, assuming the week starts Monday.
I have exploited the group by function to extract the minimum datetime value which in my case is guaranteed to be at least once daily.
This will not work if your data is not being injected daily!
select
count(*) as 'count',
date_format(min(added_on), '%Y-%M-%d') as 'week commencing',
date_format(added_on, '%Y%u') as 'week'
from
system
where
added_on >= '2007-05-16'
group by
week
order by 3 desc;
+-------+-----------------+--------+
| count | week commencing | week |
+-------+-----------------+--------+
| 88 | 2007-June-04 | 200723 |
| 276 | 2007-May-28 | 200722 |
| 275 | 2007-May-21 | 200721 |
| 160 | 2007-May-16 | 200720 |
+-------+-----------------+--------+
Hope thats useful for someone !
Imran Chaudhry
Posted by Andrew Holloway on August 8 2007 6:01pm [Delete] [Edit]
Due to a bug in mysql versions prior to 5.0.36, there is a problem when performing multiple SEC_TO_TIME conversions and there are intermediate null values. It will turn the results after the first null into null values.
For example: if you have a table (date_diff) as follows:
|id | time1 | time2 |
+------+---------+-----------+
|1 | 9:30:05 | (null)|
|2 | 10:05:07| 10:05:17|
|3 | 11:00:03| 11:01:00|
|4 | 12:05:11| (null)|
and you run a query:
select sec_to_time(time_to_sec(time1) - time_to_sec(time2)) as diff from date_diff;
You will see results as so:
| diff |
+--------+
|00:00:00|
| (null)|
| (null)|
| (null)|
And a query excluding id 1 will result in:
| diff |
+--------+
|00:00:10|
|00:00:57|
|00:00:00|
A workaround would be to use a case statement:
select case when isnull(time_to_sec(time1) - time_to_sec(time2)) then null else sec_to_time(time_to_sec(time1) - time_to_sec(time2)) end as diff from date_diff;
Or, upgrade to a mysql version including this bug fix (#25643).
Posted by Marcel Brouillet on August 16 2007 1:37pm [Delete] [Edit]
To display the date of the monday preceding a given day, Bryan Donovan suggested the following:
> SELECT DISTINCT(STR_TO_DATE(CONCAT(YEARWEEK(starttime),'1'),'%x%v%w'))
> FROM test_events;
In fact, you need to be consistent in the type of weeks you use. The above would tell you that the Monday July 16 2007 is part of the week starting... Monday July 9 2007 !
This comes from week definition ambiguities (see WEEK() above). To prevent this, specify the mode on YEARWEEK to be Monday-based : pay attention to the extra parameter to the function YEARWEEK) below
+--------------------------------+
| DATE_FORMAT('2007-07-16',"%W") |
+--------------------------------+
| Monday |
+--------------------------------+
+----------------------------------------------------------+
| STR_TO_DATE(CONCAT(YEARWEEK('2007-07-16'),'1'),'%x%v%w') |
+----------------------------------------------------------+
| 2007-07-09 |
+----------------------------------------------------------+
+------------------------------------------------------------+
| STR_TO_DATE(CONCAT(YEARWEEK('2007-07-16',1),'1'),'%x%v%w') |
+------------------------------------------------------------+
| 2007-07-16 |
+------------------------------------------------------------+
One would expect that default_week_format has the same effect on WEEKDAY() than it has on WEEK() and that setting this variable to 1 or 3 would suffice. No, as of Mysql 5.0.26 it seems to have no effect:
SET default_week_format=1;
SELECT STR_TO_DATE(CONCAT(YEARWEEK('2007-07-16'),'1'),'%x%v%w')
+----------------------------------------------------------+
| 2007-07-09 |
+----------------------------------------------------------+
Posted by Dave Holden on September 6 2007 12:43am [Delete] [Edit]
ANNIVERSARIES ARE TRICKY!
-------------------------
For versions of MySQL previous to 4.1 it is quite difficult to determine if a date field's anniversary date falls within a specified date range. Day-of-year calculations fail because of leap years and the possibility that the date range you have specified spans a year boundary. Here is what I have come up with. Hopefully it can save someone the headache and Google Fever I had to go through to come up with it.
** SOME SELECT STATEMENT ...**
WHERE
((month(Date) BETWEEN month('[MyStartDate]') AND month('[MyEndDate]')
AND
month('[MyStartDate]') <= month('[MyEndDate]')
AND
(dayofmonth(Date) >= dayofmonth('[MyStartDate]') AND month(Date)=month('[MyStartDate]')
OR
dayofmonth(Date) <= dayofmonth('[MyEndDate]') AND month(Date)=month('[MyEndDate]')
OR
month(date) > month('[MyStartDate]') AND month(date) < month('[MyEndDate]')))
OR
(
month('[MyStartDate]') > month('[MyEndDate]')
AND
(dayofmonth(Date) >= dayofmonth('[MyStartDate]') AND month(Date)=month('[MyStartDate]')
OR
dayofmonth(Date) <= dayofmonth('[MyEndDate]') AND month(Date)=month('[MyEndDate]')
OR
month(Date) > month('[MyStartDate]')
OR month(Date) < month('[MyEndDate]')
)))
Posted by Darren Edwards on September 6 2007 6:22pm [Delete] [Edit]
I was looking for a solution where I could return the number of days, hours, Minutes and seconds between two entries in a table.
DATE_DIFF is not running on my mysql server as my provider uses mysql version 4.0.25
Solution was to use to days and std time functions to calculate the difference in one call.
The fields stored in the table(report_table) are
time(00:00:00),
date(0000-00-00) and record(enum) which tells the app the type of log stored. EG start or end of a report.
SELECT
(TO_DAYS( `end`.`date` ) - TO_DAYS( `start`.`date` ))
-
( second( `end`.`time` ) + (minute( `end`.`time` )*60) + (hour( `end`.`time` )*3600)
<
second( `start`.`time` ) + (minute( `start`.`time` )*60) + (hour( `start`.`time` )*3600))
AS `days` ,
SEC_TO_TIME(
(second( `end`.`time` ) + (minute( `end`.`time` )*60) + (hour( `end`.`time` )*3600) )
-
(second( `start`.`time` ) + (minute( `start`.`time` )*60) + (hour( `start`.`time` )*3600) )
) AS `hms`,
`start`.`time` as `start`,
`end`.`time` as `end`
FROM `report_table` AS `start` , `report_table` AS `end`
AND `start`.`record` = 'Report Begin'
AND `end`.`record` = 'Report End'
LIMIT 1
If there is no end of report then it will not return a result, as you would expect.
Posted by Robert Jaemmrich on October 12 2007 7:22am [Delete] [Edit]
Birthday reminder
The next birthday (including today!) is when the person is 1 year older than he/she was yesterday. So I use
mysql> select name,birthday,adddate(birthday,interval timestampdiff(year,adddate(birthday,interval 1 day),current_date)+1 year) as next_bd from person order by next_bd;
+----------+------------+------------+
| name | birthday | next_bd |
+----------+------------+------------+
| FooToday | 1970-10-12 | 2007-10-12 |
| Bar1 | 1990-12-25 | 2007-12-25 |
| Bar2 | 2000-01-25 | 2008-01-25 |
| Foo | 1980-02-29 | 2008-02-29 |
+----------+------------+------------+
4 rows in set (0.00 sec)
mysql> select name,birthday,adddate(birthday,interval timestampdiff(year,adddate(birthday,interval 1 day),'2008-10-12')+1 year) as next_bd from person order by next_bd;
+----------+------------+------------+
| name | birthday | next_bd |
+----------+------------+------------+
| FooToday | 1970-10-12 | 2008-10-12 |
| Bar1 | 1990-12-25 | 2008-12-25 |
| Bar2 | 2000-01-25 | 2009-01-25 |
| Foo | 1980-02-29 | 2009-02-28 |
+----------+------------+------------+
4 rows in set (0.00 sec)
As you can see, this is also working for leap years.
BTW: Is "2008-02-29" plus 1 year" really "2009-02-28"? ;-)
Posted by Aaron Davidson on December 6 2007 4:05pm [Delete] [Edit]
To test if a date is a valid date:
SET @testdate="2007-02-29";
SELECT IF(@testdate=DATE_ADD(DATE_ADD(@testdate,INTERVAL 1 DAY),INTERVAL -1 DAY),TRUE,FALSE);
Returns 0 (false)
SET @testdate="2008-02-29";
SELECT IF(@testdate=DATE_ADD(DATE_ADD(@testdate,INTERVAL 1 DAY),INTERVAL -1 DAY),TRUE,FALSE);
Returns 1 (true)
Posted by Mohamed Infiyaz Zaffer Khalid on December 12 2007 1:45pm [Delete] [Edit]
Finding a date before a given number of days
Often, for certain applications, we need to subtract some days from a given date to find another date. For example, in a library, we need to go 21 days behind from the current date and list the books that were taken before that date. This would be the overdue list.
Here is a simple SQL statement. This type of use is practically essential to most apps.
SELECT SUBDATE( '2007-12-12', INTERVAL 3 DAY ) ;
The line above will give the answer 2007-12-9. To explain it further, the function SUBDATE returns a date after subtracting a specified duration. In our example, the duration is 3 days. To indicate that we are dealing with DAYS, we use the term INTERVAL. So the function above can be explained as “what is the date, three days before today?”
Now if you want to find the date 20 days before TODAY or the current system date, this is what you should do:
SELECT SUBDATE( CURRENT_DATE, INTERVAL 20 DAY )
In the statement above, we are using one of the MySQL constants that hold the current date on the server. We count 20 days back and get the answer as a result.
Happy coding.
Khalid (itsols)
Posted by Marcus Matos on January 8 2008 1:02pm [Delete] [Edit]
Important: It should be known that MySQL >= 5.0.42 silently changes the behavior of comparing a DATE column to NOW().
See: http://bugs.mysql.com/bug.php?id=28929
This breaks many things since now queries using WHERE datecol = NOW() will return NULL where previously it would return results.
Use CURDATE() instead. I'm having to go back through years of code to fix this.
Posted by Tomek Kopec on January 17 2008 1:41pm [Delete] [Edit]
refering to the document section telling about intervals in date_add / date_sub functions describing example :
SELECT DATE_ADD('1999-01-01', INTERVAL 6/4 HOUR_MINUTE);
One can avoid falling into trap simply enclosing interval 6/4 into quotation marks so the query will be look like this:
SELECT DATE_ADD('1999-01-01', INTERVAL '6/4' HOUR_MINUTE);
This case the interval will be considered as regular string and no calculation will be performed before passing as argument
Posted by Mohamed Mahir on January 23 2008 6:31am [Delete] [Edit]
Earlier I used timediff in where clause worked perfectly but don't know why it is not working now especially after cpu usage exceeds in *in two different shared hosting*
query like
select * from table where timediff(sysdate(),datetimecolumn)<25
this gets rows of last 24 hours.
Posted by Phill Pafford on May 15 2008 3:02pm [Delete] [Edit]
IF you need to run a monthly report from the 1st of each month with the previous month date, you could use the case statement below.
SELECT CASE
WHEN MONTH(CURDATE()) = 01
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* Dec */
WHEN MONTH(CURDATE()) = 02
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* Jan */
WHEN MONTH(CURDATE()) = 03 AND (YEAR(CURDATE())%4 = 0)
THEN SUBDATE(CURDATE(), INTERVAL 29 DAY) /* Feb Leap Year */
WHEN MONTH(CURDATE()) = 03 AND (YEAR(CURDATE())%4 != 0)
THEN SUBDATE(CURDATE(), INTERVAL 28 DAY) /* Feb */
WHEN MONTH(CURDATE()) = 04
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* Mar */
WHEN MONTH(CURDATE()) = 05
THEN SUBDATE(CURDATE(), INTERVAL 30 DAY) /* Apr */
WHEN MONTH(CURDATE()) = 06
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* May */
WHEN MONTH(CURDATE()) = 07
THEN SUBDATE(CURDATE(), INTERVAL 30 DAY) /* Jun */
WHEN MONTH(CURDATE()) = 08
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* Jul */
WHEN MONTH(CURDATE()) = 09
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* Aug */
WHEN MONTH(CURDATE()) = 10
THEN SUBDATE(CURDATE(), INTERVAL 30 DAY) /* Sep */
WHEN MONTH(CURDATE()) = 11
THEN SUBDATE(CURDATE(), INTERVAL 31 DAY) /* Oct */
WHEN MONTH(CURDATE()) = 12
THEN SUBDATE(CURDATE(), INTERVAL 30 DAY) /* Nov */
ELSE SUBDATE(CURDATE(), INTERVAL 30 DAY) /* Defaults to 30 days */
END
Should return 'YYYY-MM-DD' from day and interval you run it on.
Example:
if the date is Jan 1st 2008 the case will return '2007-12-01'
Added this to get the 1st of the month when you run from any day of the month
SELECT CASE
WHEN MONTH(CURDATE()) = 01
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Dec */
WHEN MONTH(CURDATE()) = 02
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Jan */
WHEN MONTH(CURDATE()) = 03 AND (YEAR(CURDATE())%4 = 0)
THEN SUBDATE(CURDATE(), INTERVAL (29 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Feb Leap Year */
WHEN MONTH(CURDATE()) = 03 AND (YEAR(CURDATE())%4 != 0)
THEN SUBDATE(CURDATE(), INTERVAL (28 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Feb */
WHEN MONTH(CURDATE()) = 04
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Mar */
WHEN MONTH(CURDATE()) = 05
THEN SUBDATE(CURDATE(), INTERVAL (30 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Apr */
WHEN MONTH(CURDATE()) = 06
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* May */
WHEN MONTH(CURDATE()) = 07
THEN SUBDATE(CURDATE(), INTERVAL (30 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Jun */
WHEN MONTH(CURDATE()) = 08
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Jul */
WHEN MONTH(CURDATE()) = 09
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Aug */
WHEN MONTH(CURDATE()) = 10
THEN SUBDATE(CURDATE(), INTERVAL (30 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Sep */
WHEN MONTH(CURDATE()) = 11
THEN SUBDATE(CURDATE(), INTERVAL (31 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Oct */
WHEN MONTH(CURDATE()) = 12
THEN SUBDATE(CURDATE(), INTERVAL (30 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Nov */
ELSE SUBDATE(CURDATE(), INTERVAL (30 - (DAYOFMONTH(CURDATE()) +1 )) DAY) /* Defaults to 30 days */
END
Posted by Thomas Schäfer on March 4 2008 2:41pm [Delete] [Edit]
Titel: Urlaubstage im laufenden Kalenderjahr anhand eines Arbeitstagemodells berechnen
Variablen $workable[First-Seventh] bool 1=Arbeitstag, 0=Kein Arbeitstag
$query ="
SELECT
SUM(effectiveworkdays(vrs.confirmed_from, vrs.confirmed_to, $workableFirst, $workableSecond, $workableThird, $workableFourth, $workableFifth, $workableSixth, $workableSeventh)) AS sum
FROM app_vacation_responses vrs
LEFT JOIN app_vacation_requests vrq ON vrs.request_id = vrq.vacation_id
WHERE vrq.requested_by = ". $employee_id ."
AND vrs.confirmed_from >= '". date('Y') ."-01-01'
AND vrs.confirmed_to <= '". date('Y') ."-12-31'
AND vrs.state = 1
group by vrq.requested_by
";
DELIMITER $$
DROP FUNCTION IF EXISTS `effectiveworkdays`$$
CREATE DEFINER=`myUserName`@`myHost` FUNCTION `effectiveworkdays`(STARTDATE date, ENDDATE date, WORKABLE1 integer, WORKABLE2 integer, WORKABLE3 integer, WORKABLE4 integer, WORKABLE5 integer, WORKABLE6 integer, WORKABLE7 integer) RETURNS int(11)
DETERMINISTIC
COMMENT 'effective working day for 2 dates'
BEGIN
DECLARE DAYCOUNT int;
DECLARE HOLIDAYCOUNT, HOLIDAYS int;
DECLARE STARTDAYS int;
DECLARE ENDDAYS int;
SET DAYCOUNT = 0;
SET HOLIDAYCOUNT = 0;
SET HOLIDAYS = 0;
SET STARTDAYS = TO_DAYS(STARTDATE) - 1 ;
SET ENDDAYS = TO_DAYS(ENDDATE);
IF (STARTDAYS <= ENDDAYS) THEN
WHILE (STARTDAYS <= ENDDAYS) DO
SET HOLIDAYCOUNT = 0;
IF(WORKABLE1=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=0) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
IF(WORKABLE2=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=1) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
IF(WORKABLE3=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=2) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
IF(WORKABLE4=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=3) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
IF(WORKABLE5=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=4) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
IF(WORKABLE6=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=5) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
IF(WORKABLE7=1 AND WEEKDAY(FROM_DAYS(STARTDAYS))=6) THEN
SET DAYCOUNT = DAYCOUNT + 1;
SELECT count(*) INTO HOLIDAYCOUNT FROM prop_holidays WHERE d_date = FROM_DAYS(STARTDAYS);
END IF;
SET STARTDAYS = STARTDAYS + 1;
SET HOLIDAYS = HOLIDAYS + HOLIDAYCOUNT;
END WHILE;
END IF;
IF ((STARTDAYS = ENDDAYS) AND (DAYCOUNT = 0)) THEN
SET DAYCOUNT = 1;
END IF;
RETURN DAYCOUNT- HOLIDAYS;
END$$
DELIMITER ;
CREATE TABLE IF NOT EXISTS `prop_holidays` (
`holiday_id` int(11) NOT NULL auto_increment,
`name` varchar(50) NOT NULL,
`d_date` date NOT NULL,
`d_type` varchar(50) default NULL,
`d_subtype` varchar(50) default NULL,
PRIMARY KEY (`holiday_id`)
) ENGINE=MyISAM;
INSERT INTO `prop_holidays` (`holiday_id`, `name`, `d_date`, `d_type`, `d_subtype`) VALUES
(35, 'newYearsDay', '2008-01-01', 'Germany', 'BadenWuerttemberg'),
(36, 'epiphany', '2008-01-06', 'Germany', 'BadenWuerttemberg'),
(37, 'goodFriday', '2008-03-21', 'Germany', 'BadenWuerttemberg'),
(38, 'easterMonday', '2008-03-24', 'Germany', 'BadenWuerttemberg'),
(39, 'dayOfWork', '2008-05-01', 'Germany', 'BadenWuerttemberg'),
(40, 'ascensionDay', '2008-05-12', 'Germany', 'BadenWuerttemberg'),
(41, 'whitMonday', '2008-05-22', 'Germany', 'BadenWuerttemberg'),
(42, 'corpusChristi', '2008-10-03', 'Germany', 'BadenWuerttemberg'),
(43, 'germanUnificationDay', '2008-11-01', 'Germany', 'BadenWuerttemberg'),
(44, 'allSaintsDay', '2008-12-25', 'Germany', 'BadenWuerttemberg'),
(45, 'xmasDay', '2008-12-26', 'Germany', 'BadenWuerttemberg');
EXAMPLE FOR SYMFONY USERS
class VacationResponse extends BaseVacationResponse
{
public function getThisYearsLeaveDaysPaidByUserSum($employee_id){
$c = new Criteria();
$c->add(EmployeePeer::EMPLOYEE_ID, $this->getRequestParameter("id"));
$tmp = EmployeePeer::doSelect($c);
$employee = $tmp[0];
$schedule = $employee->getEmploymentContract()->getWorkSchedule();
$workableFirst = $schedule->getWorkableFirst() ==1?1:0;
$workableSecond = $schedule->getWorkableSecond() ==1?1:0;
$workableThird = $schedule->getWorkableThird() ==1?1:0;
$workableFourth = $schedule->getWorkableFourth() ==1?1:0;
$workableFifth = $schedule->getWorkableFifth() ==1?1:0;
$workableSixth = $schedule->getWorkableSixth() ==1?1:0;
$workableSeventh = $schedule->getWorkableSeventh()==1?1:0;
$query ="
SELECT
sum(effectiveworkdays2(vrs.confirmed_from, vrs.confirmed_to, $workableFirst, $workableSecond, $workableThird, $workableFourth, $workableFifth, $workableSixth, $workableSeventh)) AS sum
FROM app_vacation_responses vrs
LEFT JOIN app_vacation_requests vrq ON vrs.request_id = vrq.vacation_id
WHERE vrq.requested_by = ". $employee_id ."
AND vrs.confirmed_from >= '". date('Y') ."-01-01'
AND vrs.confirmed_to <= '". date('Y') ."-12-31'
AND vrs.state = 1
group by vrq.requested_by
";
$connection = Propel::getConnection();
$statement = $connection->prepareStatement($query);
$resultset = $statement->executeQuery();
$results = null;
foreach($resultset as $result){
if($result["sum"] < 0)
$results = 0;
else
$results = $result["sum"];
}
return $results;
}
}
Posted by Jyotsna Channagiri on March 31 2008 5:41pm [Delete] [Edit]
If you want to find out the difference between date column and integer column you can do like the following:
select DATE_ADD(
col_name_DATE : Should be DATE / DATETIME data type
col_name_INTEGER : Should be INTEGER data Type
UNIT : can be MINUTE,MONTH,....
Posted by M.H. J. on May 5 2008 3:48pm [Delete] [Edit]
For MySQL 4.1 you can use this query to select the month-difference between two dates, which also takes into account the amount of days of the starting month and ending month.
1. The first part is the period_diff function to get a total amount of months between two dates. Then 1 month is subtracted (because of the next two parts).
2. The second part is to calculate the part of the starting-month (results in 1 month for dates starting on the first of the month, like 01-01-2008)
3. The third part is to calculate the part of the ending-month (results in 0 for dates starting on the first of the month, like 01-02-2008)
PERIOD_DIFF(DATE_FORMAT(`end_date`,'%Y%m'),DATE_FORMAT(`start_date`,'%Y%m'))
-1
+ (TO_DAYS(LAST_DAY(`start_date`)) + 1 - TO_DAYS(DATE_FORMAT(`start_date`,'%Y-%m-%d')))/(TO_DAYS(LAST_DAY(`start_date`)) + 1 - to_days(DATE_FORMAT(`start_date`,'%Y-%m-01')))
+ (DAY(`end_date`)-1)/(TO_DAYS(LAST_DAY(`end_date`)) + 1 - TO_DAYS(DATE_FORMAT(`end_date`,'%Y-%m-01')))
Posted by Patrick Bernier on May 10 2008 6:06pm [Delete] [Edit]
A safe and simple way to calculate the age of someone/something:
CREATE FUNCTION age (_d DATETIME) RETURNS INTEGER
COMMENT 'Given birthdate, returns current age'
RETURN YEAR(NOW()) - YEAR(_d) - IF(DATE_FORMAT(_d, '%c%d') > DATE_FORMAT(NOW(), '%c%d'), 1, 0);
Posted by Andy Fugate on May 23 2008 8:56pm [Delete] [Edit]
I work for a publishing company and recently had a request to show the modification date/time for an article as either minutes ago, hours ago, yesterday, or date of last modification depending on how recently the article was last modified. Here's a copy of the case statement I used for this:
CASE
WHEN modified_date between date_sub(now(), INTERVAL 60 minute) and now() THEN concat(minute(TIMEDIFF(now(), modified_date)), ' minutes ago')
WHEN datediff(now(), modified_date) = 1 THEN 'Yesterday'
WHEN modified_date between date_sub(now(), INTERVAL 24 hour) and now() THEN concat(hour(TIMEDIFF(NOW(), modified_date)), ' hours ago')
ELSE date_format(modified_date, '%a, %m/%d/%y')
END
Note that the "yesterday" check occurs before the "hours" check. This is intentional so that hours will only be shown if the modification occurred during the current day.
Hope this is useful for someone else!
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