数据表：

mysql 如何去重

sql代码：


delete  FROM  test where id NOT in(  select id FROM tmp  )


create table tmp (select id FROM test GROUP BY `name` )

tmp是创建的临时表，不需要提前创建，直接写接好，

为什么要创建临时表，看下面：

mysql 如何去重

直接写会报错：

delete FROM test where id NOT in( select id FROM test GROUP BY `name` )

[SQL]

delete FROM test where id NOT in( select id FROM test GROUP BY `name` )

[Err] 1093 - You can't specify target table 'test' for update in FROM clause

要先运行create table tmp (select id FROM test GROUP BY `name` )