timediff
description
Syntax
TIME TIMEDIFF(DATETIME expr1, DATETIME expr2)
TIMEDIFF返回两个DATETIME之间的差值
TIMEDIFF函数返回表示为时间值的expr1 - expr2的结果，返回值为TIME类型
example
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 |
+---------------------------------------+keywords
TIMEDIFF