Question

description

Syntax

DATETIME TIME_ROUND(DATETIME expr)

DATETIME TIME_ROUND(DATETIME expr, INT period)

DATETIME TIME_ROUND(DATETIME expr, DATETIME origin)

DATETIME TIME_ROUND(DATETIME expr, INT period, DATETIME origin)

函数名 TIME_ROUND 由两部分组成，每部分由以下可选值组成

• TIME: SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, YEAR
• ROUND: FLOOR, CEIL

返回 expr 的上/下界。

• period 指定每个周期有多少个 TIME 单位组成，默认为 1。
• origin 指定周期的开始时间，默认为 1970-01-01T00:00:00，WEEK 的默认开始时间为 1970-01-04T00:00:00，即周日。可以比 expr 大。
• 请尽量选择常见 period，如 3 MONTH，90 MINUTE 等，如设置了非常用 period，请同时指定 origin。

example

MySQL> SELECT YEAR_FLOOR('20200202000000');
+------------------------------+
| year_floor('20200202000000') |
+------------------------------+
| 2020-01-01 00:00:00          |
+------------------------------+


MySQL> SELECT MONTH_CEIL(CAST('2020-02-02 13:09:20' AS DATETIME), 3); --quarter
+--------------------------------------------------------+
| month_ceil(CAST('2020-02-02 13:09:20' AS DATETIME), 3) |
+--------------------------------------------------------+
| 2020-04-01 00:00:00                                    |
+--------------------------------------------------------+


MySQL> SELECT WEEK_CEIL('2020-02-02 13:09:20', '2020-01-06'); --monday
+---------------------------------------------------------+
| week_ceil('2020-02-02 13:09:20', '2020-01-06 00:00:00') |
+---------------------------------------------------------+
| 2020-02-03 00:00:00                                     |
+---------------------------------------------------------+


MySQL> SELECT MONTH_CEIL(CAST('2020-02-02 13:09:20' AS DATETIME), 3, CAST('1970-01-09 00:00:00' AS DATETIME)); --next rent day
+-------------------------------------------------------------------------------------------------+
| month_ceil(CAST('2020-02-02 13:09:20' AS DATETIME), 3, CAST('1970-01-09 00:00:00' AS DATETIME)) |
+-------------------------------------------------------------------------------------------------+
| 2020-04-09 00:00:00                                                                             |
+-------------------------------------------------------------------------------------------------+

keyword

TIME_ROUND