参考文章：
http://database.51cto.com/art/201011/235159.htm
1，查找表中多余的重复记录，重复记录是根据单个字段来判断
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，查找表中对于的重复记录（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），只保留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)
