DATE_FLOOR

描述

date_floor 将日期转化为指定的时间间隔周期的最近下取整时刻。

语法

DATE_FLOOR(<datetime>, INTERVAL <period> <type>)

参数

参数	说明
datetime	参数是合法的日期表达式
period	参数是指定每个周期有多少个单位组成，开始的时间起点为0001-01-01T00:00:00
type	参数可以是：YEAR, MONTH, DAY, HOUR, MINUTE, SECOND

返回值

返回的是一个日期或时间值，表示将输入值向下舍入到指定单位的结果。

举例

select date_floor("0001-01-01 00:00:16",interval 5 second);

+---------------------------------------------------------------+
| second_floor('0001-01-01 00:00:16', 5, '0001-01-01 00:00:00') |
+---------------------------------------------------------------+
| 0001-01-01 00:00:15                                           |
+---------------------------------------------------------------+

select date_floor("0001-01-01 00:00:18",interval 5 second);

+---------------------------------------------------------------+
| second_floor('0001-01-01 00:00:18', 5, '0001-01-01 00:00:00') |
+---------------------------------------------------------------+
| 0001-01-01 00:00:15                                           |
+---------------------------------------------------------------+

select date_floor("2023-07-13 22:28:18",interval 5 minute);

+---------------------------------------------------------------+
| minute_floor('2023-07-13 22:28:18', 5, '0001-01-01 00:00:00') |
+---------------------------------------------------------------+
| 2023-07-13 22:25:00                                           |
+---------------------------------------------------------------+

select date_floor("2023-07-13 22:28:18",interval 5 hour);

+-------------------------------------------------------------+
| hour_floor('2023-07-13 22:28:18', 5, '0001-01-01 00:00:00') |
+-------------------------------------------------------------+
| 2023-07-13 18:00:00                                         |
+-------------------------------------------------------------+

select date_floor("2023-07-13 22:28:18",interval 5 day);

+------------------------------------------------------------+
| day_floor('2023-07-13 22:28:18', 5, '0001-01-01 00:00:00') |
+------------------------------------------------------------+
| 2023-07-10 00:00:00                                        |
+------------------------------------------------------------+

select date_floor("2023-07-13 22:28:18",interval 5 month);

+--------------------------------------------------------------+
| month_floor('2023-07-13 22:28:18', 5, '0001-01-01 00:00:00') |
+--------------------------------------------------------------+
| 2023-07-01 00:00:00                                          |
+--------------------------------------------------------------+

select date_floor("2023-07-13 22:28:18",interval 5 year);

+-------------------------------------------------------------+
| year_floor('2023-07-13 22:28:18', 5, '0001-01-01 00:00:00') |
+-------------------------------------------------------------+
| 2021-01-01 00:00:00                                         |
+-------------------------------------------------------------+