在 MySQL 表中为某个值添加 30 天?
mysqlmysqli database
要为表中某个值添加 30 天，可以使用 ADDDATE() 函数和 UPDATE 命令。语法如下:
UPDATE yourTableName SET yourDateColumnName=ADDDATE(yourDateColumnName,INTERVAL 30 DAY);
为了理解上述语法，让我们创建一个表。创建表的查询如下:
mysql> create table Add30DayDemo -> ( -> Id int NOT NULL AUTO_INCREMENT, -> ShippingDate date, -> PRIMARY KEY(ID) -> ); Query OK, 0 rows affected (0.76 sec)
使用插入命令在表中插入一些记录。查询如下:
mysql> insert into Add30DayDemo(ShippingDate) values('2019-02-04');
Query OK, 1 row affected (0.20 sec)
mysql> insert into Add30DayDemo(ShippingDate) values('2018-11-15');
Query OK, 1 row affected (0.18 sec)
mysql> insert into Add30DayDemo(ShippingDate) values('2013-05-18');
Query OK, 1 row affected (0.15 sec)
mysql> insert into Add30DayDemo(ShippingDate) values('2017-08-25');
Query OK, 1 row affected (0.20 sec)
mysql> insert into Add30DayDemo(ShippingDate) values('2016-03-01');
Query OK, 1 row affected (0.12 sec)
mysql> insert into Add30DayDemo(ShippingDate) values('2015-09-03');
Query OK, 1 row affected (0.13 sec)
使用 select 语句显示表中的所有记录。查询如下:
mysql> select *from Add30DayDemo;
输出结果如下:
+----+--------------+ | Id | ShippingDate | +----+--------------+ | 1 | 2019-02-04 | | 2 | 2018-11-15 | | 3 | 2013-05-18 | | 4 | 2017-08-25 | | 5 | 2016-03-01 | | 6 | 2015-09-03 | +----+--------------+ 6 rows in set (0.00 sec)
以下是使用 DATEADD() 在表中添加 30 天值的查询:
mysql> update Add30DayDemo -> SET ShippingDate=ADDDATE(ShippingDate,INTERVAL 30 DAY); Query OK, 6 rows affected (0.44 sec) Rows matched: 6 Changed: 6 Warnings: 0
现在再次检查表记录。查询如下:
mysql> select *from Add30DayDemo;
以下是更新日期后的输出:
+----+--------------+ | Id | ShippingDate | +----+--------------+ | 1 | 2019-03-06 | | 2 | 2018-12-15 | | 3 | 2013-06-17 | | 4 | 2017-09-24 | | 5 | 2016-03-31 | | 6 | 2015-10-03 | +----+--------------+ 6 rows in set (0.00 sec)
