oracle_删除同一列的重复数据

      <!--删除同一列的重复数据  rowid 在orcle中 数据的物理地址--->
      
        

delete 
      
      
        from
      
      
         tbl_over_picture_alarm a

 where rowid 
      
      
        not
      
      
        in
      
      
         (select min(b.rowid)

                       
      
      
        from
      
      
         tbl_over_picture_alarm b

                      where a.picture_url 
      
      =
      
         b.picture_url )