1、根据rowid来查询重复数据

select * from table1 a where rowid !=(select max(rowid) 
from table1 b where a.name1=b.name1 )

2、根据rowid来删除重复数据

delete  from table1 a where rowid !=(select max(rowid) 
from table1 b where a.name1=b.name1 )

3、根据group by来查询重复数据

select * from people
where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)

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

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