adddate(date,INTERVAL expr unit), adddate(expr,days)
当第二个参数INTERVAL形式调用, ADDDATE() 是DATE_ADD() 的同义词。相关函数SUBDATE() 是 DATE_SUB()的同义词。有关INTERVAL单位参数信息,请参阅DATE_ADD()的相关讨论。
mysql> SELECT DATE_ADD('1998-01-02', INTERVAL 31 DAY); +---------------------------------------------------------+ | DATE_ADD('1998-01-02', INTERVAL 31 DAY) | +---------------------------------------------------------+ | 1998-02-02 | +---------------------------------------------------------+ 1 row in set (0.00 sec) mysql> SELECT ADDDATE('1998-01-02', INTERVAL 31 DAY); +---------------------------------------------------------+ | ADDDATE('1998-01-02', INTERVAL 31 DAY) | +---------------------------------------------------------+ | 1998-02-02 | +---------------------------------------------------------+ 1 row in set (0.00 sec)
当第二个参数的使用天的形式调用,MySQL将其视为被添加天的整数到expr。
mysql> SELECT ADDDATE('1998-01-02', 31); +---------------------------------------------------------+ | DATE_ADD('1998-01-02', INTERVAL 31 DAY) | +---------------------------------------------------------+ | 1998-02-02 | +---------------------------------------------------------+ 1 row in set (0.00 sec)