sql语句删除重复

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)