SQL 删除数据库中重复数据 保留一条

//查看重复记录语句

//说明：WP_Search_History → 数据库表名；SH_ID → 为标识列名（唯一）；SH_PageURL → 为有重复数据的列名

 

select SH_ID from WP_Search_History  s1 where SH_ID  not in (
select max(SH_ID) from WP_Search_History s2 where s1.SH_PageURL =s2.SH_PageURL )

 

//删除重复记录

//说明：WP_Search_History → 数据库表名；SH_ID → 为标识列名（唯一）；SH_PageURL → 为有重复数据的列名

 

delete from WP_Search_History  where SH_ID in(

select SH_ID from WP_Search_History  s1 where SH_ID  not in (
select max(SH_ID) from WP_Search_History s2 where s1.SH_PageURL =s2.SH_PageURL ))