在MySQL中用新值替换特定的重复记录
让我们首先创建一个表-
mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Name varchar(50) );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable(Name) values('Chris');
mysql> insert into DemoTable(Name) values('Robert');
mysql> insert into DemoTable(Name) values('Chris');
mysql> insert into DemoTable(Name) values('David');
mysql> insert into DemoTable(Name) values('Mike');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-
+----+--------+ | Id | Name | +----+--------+ | 1 | Chris | | 2 | Robert | | 3 | Chris | | 4 | David | | 5 | Mike | +----+--------+ 5 rows in set (0.00 sec)
这是用新名称替换特定重复记录（即名称“Chris”）的查询-
mysql> update DemoTable set Name=replace(Name,'Chris','Adam Smith'); Rows matched: 5 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-
+----+------------+ | Id | Name | +----+------------+ | 1 | Adam Smith | | 2 | Robert | | 3 | Adam Smith | | 4 | David | | 5 | Mike | +----+------------+ 5 rows in set (0.00 sec)