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)
补充：
有两个以上的重复记录，一是完全重复的记录，也即所有字段均重复的记录，二是部分关键字段重复的记录，比如Name字段重复，而其他字段不一定重复或都重复可以忽略。
1、对于第一种重复，比较容易解决，使用
select
distinct * from
tableName
就可以得到无重复记录的结果集。
如果该表需要删除重复的记录（重复记录保留1条），可以按以下方法删除
select
distinct * into #Tmp from tableName
drop table tableName
select * into
tableName from #Tmp
drop table
#Tmp
发生这种重复的原因是表设计不周产生的，增加唯一索引列即可解决。
2、这类重复问题通常要求保留重复记录中的第一条记录，操作方法如下
假设有重复的字段为Name,Address，要求得到这两个字段唯一的结果集
select
identity(int,1,1) as autoID, * into #Tmp from tableName
select min(autoID) as
autoID into #Tmp2 from #Tmp group by Name,autoID
select * from #Tmp where
autoID in(select autoID from
#tmp2)
最后一个select即得到了Name，Address不重复的结果集（但多了一个autoID字段，实际写时可以写在select子句中省去此列）