timediff

返回两个 DATETIME 表达式之间的差值。

返回值必须为 TIME 类型。

语法

TIME TIMEDIFF(DATETIME expr1, DATETIME expr2)`

示例

MySQL > SELECT TIMEDIFF(now(),utc_timestamp());
+----------------------------------+
| timediff(now(), utc_timestamp()) |
+----------------------------------+
| 08:00:00                         |
+----------------------------------+

MySQL > SELECT TIMEDIFF('2019-07-11 16:59:30','2019-07-11 16:59:21');
+--------------------------------------------------------+
| timediff('2019-07-11 16:59:30', '2019-07-11 16:59:21') |
+--------------------------------------------------------+
| 00:00:09                                               |
+--------------------------------------------------------+

MySQL > SELECT TIMEDIFF('2019-01-01 00:00:00', NULL);
+---------------------------------------+
| timediff('2019-01-01 00:00:00', NULL) |
+---------------------------------------+
| NULL                                  |
+---------------------------------------+

关键词

TIMEDIFF