date_trunc

date_trunc

SinceVersion 1.2.0

date_trunc

Description

Syntax

DATETIME DATE_TRUNC(DATETIME datetime, VARCHAR unit)

Truncates datetime in the specified time unit.

datetime is a legal date expression.

unit is the time unit you want to truncate. The optional values are as follows: [second,minute,hour,day,week,month,quarter,year]。 If unit does not meet the above optional values, the result will return NULL.

example

mysql> select date_trunc('2010-12-02 19:28:30', 'second');
+-------------------------------------------------+
| date_trunc('2010-12-02 19:28:30', 'second')     |
+-------------------------------------------------+
| 2010-12-02 19:28:30                             |
+-------------------------------------------------+

mysql> select date_trunc('2010-12-02 19:28:30', 'minute');
+-------------------------------------------------+
| date_trunc('2010-12-02 19:28:30', 'minute')     |
+-------------------------------------------------+
| 2010-12-02 19:28:00                             |
+-------------------------------------------------+

mysql> select date_trunc('2010-12-02 19:28:30', 'hour');
+-------------------------------------------------+
| date_trunc('2010-12-02 19:28:30', 'hour')       |
+-------------------------------------------------+
| 2010-12-02 19:00:00                             |
+-------------------------------------------------+

mysql> select date_trunc('2010-12-02 19:28:30', 'day');
+-------------------------------------------------+
| date_trunc('2010-12-02 19:28:30', 'day')        |
+-------------------------------------------------+
| 2010-12-02 00:00:00                             |
+-------------------------------------------------+

mysql> select date_trunc('2010-12-02 19:28:30', 'week');
+-------------------------------------------+
| date_trunc('2010-12-02 19:28:30', 'week') |
+-------------------------------------------+
| 2010-11-29 00:00:00                       |
+-------------------------------------------+

mysql> select date_trunc('2010-12-02 19:28:30', 'month');
+-------------------------------------------------+
| date_trunc('2010-12-02 19:28:30', 'month')      |
+-------------------------------------------------+
| 2010-12-01 00:00:00                             |
+-------------------------------------------------+

mysql> select date_trunc('2010-12-02 19:28:30', 'quarter');
+-------------------------------------------------+
| date_trunc('2010-12-02 19:28:30', 'quarter')    |
+-------------------------------------------------+
| 2010-10-01 00:00:00                             |
+-------------------------------------------------+

mysql> select date_trunc('2010-12-02 19:28:30', 'year');
+-------------------------------------------------+
| date_trunc('2010-12-02 19:28:30', 'year')       |
+-------------------------------------------------+
| 2010-01-01 00:00:00                             |
+-------------------------------------------------+

keywords

DATE_TRUNC,DATE,DATETIME