days_sub

从日期或日期时间中减去指定的天数以获取新的日期时间。

语法

DATETIME days_sub(DATETIME|DATE d, INT n);

参数

d: 日期或日期时间表达式。

n: 从 d 中减去的天数。

返回值

返回日期时间类型的值，如果任何参数为 NULL 或无效，则返回 NULL。

如果结果超出范围 [0000-01-01 00:00:00, 9999-12-31 00:00:00]，则返回 NULL。

示例

SELECT DAYS_SUB('2022-12-20 12:00:00', 10);
+--------------------------------------------------+
| days_sub('2022-12-20 12:00:00', INTERVAL 10 DAY) |
+--------------------------------------------------+
| 2022-12-10 12:00:00                              |
+--------------------------------------------------+

SELECT DAYS_SUB('2022-12-20 12:00:00', -10);
+---------------------------------------------------+
| days_sub('2022-12-20 12:00:00', INTERVAL -10 DAY) |
+---------------------------------------------------+
| 2022-12-30 12:00:00                               |
+---------------------------------------------------+

SELECT DAYS_SUB('2022-12-20 12:00:00', 738874);
+------------------------------------------------------+
| days_sub('2022-12-20 12:00:00', INTERVAL 738874 DAY) |
+------------------------------------------------------+
| 0000-01-01 12:00:00                                  |
+------------------------------------------------------+

SELECT DAYS_SUB('2022-12-20 12:00:00', 738875);
+------------------------------------------------------+
| days_sub('2022-12-20 12:00:00', INTERVAL 738875 DAY) |
+------------------------------------------------------+
| NULL                                                 |
+------------------------------------------------------+

SELECT DAYS_SUB('2022-12-20 12:00:00', -2913550);
+--------------------------------------------------------+
| days_sub('2022-12-20 12:00:00', INTERVAL -2913550 DAY) |
+--------------------------------------------------------+
| 9999-12-31 12:00:00                                    |
+--------------------------------------------------------+

SELECT DAYS_SUB('2022-12-20 12:00:00', -2913551);
+--------------------------------------------------------+
| days_sub('2022-12-20 12:00:00', INTERVAL -2913551 DAY) |
+--------------------------------------------------------+
| NULL                                                   |
+--------------------------------------------------------+

关键字

DAY,day