把所有不唯一的组合查出来
select col1,col2 from test group by col1,col2 having count(*) >1
把所有不唯一的组合删除
delete from test where exists select 1 from test group by col1,col2 having count(*) >1
把所有不唯一的组合查出来
select col1,col2 from test group by col1,col2 having count(*) >1
把所有不唯一的组合删除
delete from test where exists select 1 from test group by col1,col2 having count(*) >1