仅更新MySQL表中的单个列，并根据条件进行递增
让我们首先创建一个表-
mysql> create table DemoTable ( Name varchar(50), Score int );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable values('Sam',45);
mysql> insert into DemoTable values('Mike',28);
mysql> insert into DemoTable values('Carol',27);
mysql> insert into DemoTable values('David',67);使用select语句显示表中的所有记录-
mysql> select *from DemoTable;
这将产生以下输出-
+-------+-------+ | Name | Score | +-------+-------+ | Sam | 45 | | Mike | 28 | | Carol | 27 | | David | 67 | +-------+-------+ 4 rows in set (0.00 sec)
以下是仅更新单个列并根据条件递增的查询-
mysql> update DemoTable set Score=Score+10 where Score < 30; Rows matched: 2 Changed: 2 Warnings: 0
让我们再次检查表记录-
mysql> select *from DemoTable;
这将产生以下输出-
+-------+-------+ | Name | Score | +-------+-------+ | Sam | 45 | | Mike | 38 | | Carol | 37 | | David | 67 | +-------+-------+ 4 rows in set (0.00 sec)