MySQL查询增加列值之一
让我们首先创建一个表-
mysql> create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Name varchar(100), -> Score int -> );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable(Name,Score) values('John',68);
mysql> insert into DemoTable(Name,Score) values('Carol',98);
mysql> insert into DemoTable(Name,Score) values('David',89);
mysql> insert into DemoTable(Name,Score) values('Robert',67);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-
+----+--------+-------+ | Id | Name | Score | +----+--------+-------+ | 1 | John | 68 | | 2 | Carol | 98 | | 3 | David | 89 | | 4 | Robert | 67 | +----+--------+-------+ 4 rows in set (0.00 sec)
以下是将列值之一增加1的查询-
mysql> update DemoTable set Score=Score+1 where Id=3; Rows matched: 1 Changed: 1 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-
+----+--------+-------+ | Id | Name | Score | +----+--------+-------+ | 1 | John | 68 | | 2 | Carol | 98 | | 3 | David | 90 | | 4 | Robert | 67 | +----+--------+-------+ 4 rows in set (0.00 sec)