关键是用好  group by  子句　　1、查找表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断　　select * from people　　where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)　　2、删除表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断，只留有rowid最小的记录　　delete from people　　where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)　　and rowid not in (select min(rowid) from people group by peopleId having count(peopleId )>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)