如何从包含重复记录的 MySQL 表中删除单个值?
mysqlmysqli database
使用 DELETE 删除记录，但如果有多个重复记录，则使用 MySQL LIMIT 限制删除，如以下语法所示 −
语法
delete from yourTableName where yourColumnName=yourValue limit 1;
首先我们创建一个表 −
mysql> create table DemoTable -> ( -> Amount int -> ); Query OK, 0 rows affected (1.38 sec)
使用 insert 命令在表中插入一些记录 −
mysql> insert into DemoTable values(50); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values(100); Query OK, 1 row affected (0.36 sec) mysql> insert into DemoTable values(50); Query OK, 1 row affected (0.59 sec) mysql> insert into DemoTable values(70); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(90); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(50); Query OK, 1 row affected (0.23 sec)
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 −
+--------+ | Amount | +--------+ | 50 | | 100 | | 50 | | 70 | | 90 | | 50 | +--------+ 6 rows in set (0.00 sec)
这是从表中删除单个值的查询 −
mysql> delete from DemoTable where Amount=50 limit 1; Query OK, 1 row affected (0.39 sec)
让我们再次检查表记录 −
mysql> select *from DemoTable;
这将产生以下输出 −
+--------+ | Amount | +--------+ | 100 | | 50 | | 70 | | 90 | | 50 | +--------+ 5 rows in set (0.00 sec)
