MySQL gets the current date time function
Source: http://www.cnblogs.com/ggjucheng/p/3352280.html
Get the current date + time (date + times) function: Now ()
Mysql> Select Now (); +---------------------+| Now () |+---------------------+| 2008-08-08 22:20:46 |+---------------------+
MySQL Gets the current timestamp function: Current_timestamp, Current_timestamp ()
Mysql> Select Current_timestamp, Current_timestamp (), +---------------------+---------------------+| Current_timestamp | Current_timestamp () |+---------------------+---------------------+| 2008-08-09 23:22:24 | 2008-08-09 23:22:24 |+---------------------+---------------------+
MySQL Date conversion function, time conversion function
MySQL Date/time to STR (date/time converted to string) function: Date_format (Date,format), Time_format (Time,format)
Mysql> Select Date_format (' 2008-08-08 22:23:01 ', '%y%m%d%h%i%s '); +--------------------------------------------- -------+| Date_format (' 2008-08-08 22:23:01 ', '%y%m%d%h%i%s ') |+----------------------------------------------------+| 20080808222301 |+----------------------------------------------------+
MySQL (Unix timestamp, date) conversion function
Unix_timestamp (), Unix_timestamp (date), From_unixtime (Unix_timestamp), From_unixtime (Unix_timestamp,format)
Select Unix_timestamp (); --1218290027select Unix_timestamp (' 2008-08-08 '); --1218124800select Unix_timestamp (' 2008-08-08 12:30:00 '); --1218169800select From_unixtime (1218290027); --' 2008-08-09 21:53:47 ' select From_unixtime (1218124800); --' 2008-08-08 00:00:00 ' select From_unixtime (1218169800); --' 2008-08-08 12:30:00 ' select From_unixtime (1218169800, '%Y%d%M%h:%i:%s%x '); --' 8th August 12:30:00 2008 '
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Php+mysql How the date time is converted
Programmers who have written php+mysql know there is a time lag,Unix timestamps and formatted dates are two time representations that we often deal with, Unix timestamp storage, easy processing, but not intuitive, formatted date intuitive, But the processing is not as easy as the Unix timestamp, so sometimes it is necessary to convert each other, the following gives the conversion of several different ways.
One, complete in MySQL
This way in the MySQL query statement conversion, the advantage is not to occupy PHP parser parsing time, fast, the disadvantage is only used in database query, there are limitations.
1. UNIX timestamp converted to date function: From_unixtime ()
General form: Select From_unixtime (1156219870);
2. Date conversion to UNIX timestamp function: Unix_timestamp ()
General form: Select unix_timestamp (' 2006-11-04 12:23:00′);
Example: MySQL Query the number of records on the day:
$sql = "SELECT *" from the message Where date_format (From_unixtime (chattime), '%y-%m-%d ') = Date_format (now (), '%y-%m-%d ') ORDER BY id DESC ";
Second, complete in PHP
This way in the PHP program to complete the conversion, the advantage is that the database is not the data can be converted, the scope of the conversion is not limited, the disadvantage is to occupy the parsing time of the PHP parser, the speed is relatively slow.
1. UNIX timestamp converted to date function: Date ()
General form: Date (' y-m-d h:i:s ', 1156219870);
2. Date conversion to UNIX timestamp function: Strtotime ()
General form: Strtotime (' 2010-03-24 08:15:42 ');
MYSQL \ PHP Date functions convert each other