ADDDATE(date,INTERVAL expr unit), ADDDATE(expr,days)

當第二個參數INTERVAL形式調用，ADDDATE() 是DATE_ADD()的同義詞。 相關函數SUBDATE()是DATE_SUB()同義詞。 有關INTERVAL 參數信息，請參閱DATE_ADD()的討論。

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)

當第二個參數days 的形式調用時，MySQL將其視為整數天數添加到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)