在 MySQL 中用新值替换特定重复记录
我们先创建一个表格 -
mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Name varchar(50) ); Query OK, 0 rows affected (0.62 sec)
使用 insert 命令在表格中插入一些记录 -
mysql> insert into DemoTable(Name) values('Chris'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(Name) values('Robert'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(Name) values('Chris'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable(Name) values('David'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable(Name) values('Mike'); Query OK, 1 row affected (0.13 sec)
使用 select 语句显示表格中的所有记录 -
mysql> select *from DemoTable;
这会产生以下输出 -
+----+--------+ | Id | Name | +----+--------+ | 1 | Chris | | 2 | Robert | | 3 | Chris | | 4 | David | | 5 | Mike | +----+--------+ 5 rows in set (0.00 sec)
以下是替换特定重复记录(此处为名称“Chris”)为新名称的查询 -
mysql> update DemoTable set Name=replace(Name,'Chris','Adam Smith'); Query OK, 2 rows affected (0.17 sec) Rows matched: 5 Changed: 2 Warnings: 0
让我们再次检查表格记录 -
mysql> select *from DemoTable;
这会产生以下输出 -
+----+------------+ | Id | Name | +----+------------+ | 1 | Adam Smith | | 2 | Robert | | 3 | Adam Smith | | 4 | David | | 5 | Mike | +----+------------+ 5 rows in set (0.00 sec)
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