MySQL查询通过串联来更新字符串字段吗？
要连接字符串字段，请使用CONCAT()function。让我们首先创建一个表-
mysql> create table DemoTable -> ( -> SequenceId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> StudentId varchar(100) -> );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable(StudentId) values('STU');
mysql> insert into DemoTable(StudentId) values('STU1');使用select语句显示表中的所有记录-
mysql> select *from DemoTable;
输出结果
+------------+-----------+ | SequenceId | StudentId | +------------+-----------+ | 1 | STU | | 2 | STU1 | +------------+-----------+ 2 rows in set (0.00 sec)
这是通过串联来更新字符串字段的查询-
mysql> update DemoTable -> set StudentId=concat(StudentId,'-','101'); Rows matched: 2 Changed: 2 Warnings: 0
让我们再次从表中检查所有记录-
mysql> select *from DemoTable;
输出结果
+------------+-----------+ | SequenceId | StudentId | +------------+-----------+ | 1 | STU-101 | | 2 | STU1-101 | +------------+-----------+ 2 rows in set (0.00 sec)