MySQL查询将值减小10以获得特定值？
让我们首先创建一个表-
mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Score int );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable(Score) values(67); mysql> insert into DemoTable(Score) values(78); mysql> insert into DemoTable(Score) values(90); mysql> insert into DemoTable(Score) values(56);
使用select语句显示表中的所有记录-
mysql> select *from DemoTable;
输出结果
+----+-------+ | Id | Score | +----+-------+ | 1 | 67 | | 2 | 78 | | 3 | 90 | | 4 | 56 | +----+-------+ 4 rows in set (0.00 sec)
以下是针对特定值将值减少10的查询-
mysql> update DemoTable set Score=Score-10 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
+----+-------+ | Id | Score | +----+-------+ | 1 | 67 | | 2 | 78 | | 3 | 80 | | 4 | 56 | +----+-------+ 4 rows in set (0.00 sec)