DATE_TRUNC

描述

将 datetime 按照指定的时间单位截断。

语法

DATE_TRUNC(<datetime>, <time_unit>)
DATE_TRUNC(<time_unit>, <datetime>)

参数

参数	说明
`<datetime>`	合法的日期表达式
`<time_unit>`	希望截断的时间间隔，可选的值如下：[`second`,`minute`,`hour`,`day`,`week`,`month`,`quarter`,`year`]

返回值

按照指定的时间单位截断的时间

举例

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                             |
+-------------------------------------------------+

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                             |
+-------------------------------------------------+

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                             |
+-------------------------------------------------+

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                             |
+-------------------------------------------------+

select date_trunc('2023-4-05 19:28:30', 'week');

+-------------------------------------------+
| date_trunc('2023-04-05 19:28:30', 'week') |
+-------------------------------------------+
| 2023-04-03 00:00:00                       |
+-------------------------------------------+

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                             |
+-------------------------------------------------+

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                             |
+-------------------------------------------------+

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                             |
+-------------------------------------------------+

DATE_SUB DATE