MySQL DATE_ADD根据另一列中的值增加日期？

让我们首先创建一个表，其中一个列为DueDate，另一个为“RepeatTime”(重复次数)，该表显示了用户提交付款的次数-

mysql> create table DemoTable -> ( -> DueDate date, -> RepeatTime int -> ); Query OK, 0 rows affected (0.57 sec)

使用插入命令在表中插入一些记录-

mysql> insert into DemoTable values(2019-01-23,3); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(2019-06-22,6); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values(2019-03-28,2); Query OK, 1 row affected (0.25 sec) mysql> insert into DemoTable values(2017-07-25,6); Query OK, 1 row affected (0.15 sec)

使用select语句显示表中的所有记录-

mysql> select *from DemoTable;

输出结果

这将产生以下输出-

+------------+------------+ | DueDate | RepeatTime | +------------+------------+ | 2019-01-23 | 3 | | 2019-06-22 | 6 | | 2019-03-28 | 2 | | 2017-07-25 | 6 | +------------+------------+ 4 rows in set (0.00 sec)

这是根据另一列中的值递增日期的查询-

mysql> update DemoTable set DueDate=date_add(DueDate,interval RepeatTime MONTH) where RepeatTime!=6; Query OK, 2 rows affected (0.25 sec) Rows matched: 2 Changed: 2 Warnings: 0

让我们再次检查表记录-

mysql> select *from DemoTable;

输出结果

这将产生以下输出-

+------------+------------+ | DueDate | RepeatTime | +------------+------------+ | 2019-04-23 | 3 | | 2019-06-22 | 6 | | 2019-05-28 | 2 | | 2017-07-25 | 6 | +------------+------------+ 4 rows in set (0.00 sec)