在MySQL中仅更新单个列值？
让我们首先创建一个表-
mysql> create table DemoTable770 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Value int );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable770(Value) values(10); mysql> insert into DemoTable770(Value) values(90); mysql> insert into DemoTable770(Value) values(160); mysql> insert into DemoTable770(Value) values(450); mysql> insert into DemoTable770(Value) values(560);
使用select语句显示表中的所有记录-
mysql> select *from DemoTable770;
这将产生以下输出-
+----+-------+ | Id | Value | +----+-------+ | 1 | 10 | | 2 | 90 | | 3 | 160 | | 4 | 450 | | 5 | 560 | +----+-------+ 5 rows in set (0.00 sec)
以下是仅更新单个列值的查询-
mysql> update DemoTable770 set Value=Value+150 where Id=4; Rows matched: 1 Changed: 1 Warnings: 0
让我们检查视图的描述-
mysql> select *from DemoTable770;
这将产生以下输出-
+----+-------+ | Id | Value | +----+-------+ | 1 | 10 | | 2 | 90 | | 3 | 160 | | 4 | 600 | | 5 | 560 | +----+-------+ 5 rows in set (0.00 sec)