【数据库】sql语句删除重复数据

用SQL语句,删除掉重复项只保留一条 在几千条记录里,存在着些相同的记录,如何能用SQL语句,删除掉重复的呢

1、查找表中多余的重复记录，重复记录是根据单个字段（trans_id）来判断

select *
  from intf_task_instance t
 where t.trans_id in (select trans_id
                        from intf_task_instance
                       group by (trans_id, intf_task_instance_id)
                      having count(trans_id) > 1);

2、删除表中多余的重复记录，重复记录是根据单个字段（intf_task_instance_id）来判断，只留有rowid最小的记录

delete from intf_task_instance t
 where t.intf_task_instance_id in
       (select intf_task_instance_id
          from intf_task_instance
         group by intf_task_instance_id
        having count(intf_task_instance_id) > 1)
   and rowid not in (select min(Rowid)
                       from intf_task_instance
                      group by intf_task_instance_id
                     having count(intf_task_instance_id) > 1);

3、查找表中多余的重复记录（多个字段）

select *
  from vitae a
 where (a.peopleId, a.seq) in (select peopleId, seq
                                 from vitae
                                group by peopleId, seq
                               having count(*) > 1)

4、删除表中多余的重复记录（多个字段），只留有rowid最小的记录

delete from vitae a
 where (a.peopleId, a.seq) in (select peopleId, seq
                                 from vitae
                                group by peopleId, seq
                               having count(*) > 1)
   and rowid not in (select min(rowid)
                       from vitae
                      group by peopleId, seq
                     having count(*) > 1)

5、查找表中多余的重复记录（多个字段），不包含rowid最小的记录

select *
  from vitae a
 where (a.peopleId, a.seq) in (select peopleId, seq
                                 from vitae
                                group by peopleId, seq
                               having count(*) > 1)
   and rowid not in (select min(rowid)
                       from vitae
                      group by peopleId, seq
                     having count(*) > 1)