1、查找全部重复记录

Select * From 表 Where 重复字段 In (Select 重复字段 From 表 Group By 重复字段 Having Count(*)>1)  

2、过滤重复记录(只显示一条)

Select * From 表 Where ID In (Select Max(ID) From 表 Group By Title)     #显示ID最大一条记录

3、删除全部重复记录

Delete 表 Where 重复字段 In (Select 重复字段 From 表 Group By 重复字段 Having Count(*)>1)  

4、删除全部重复记录保留最大ID最大一条记录

Delete 表 Where ID Not In (Select Max(ID) From 表 Group By Title)    #保留ID最大一条记录

5、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)  

6、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)  

7、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)  

说明:
单表的唯一查询用:distinct
多表的唯一查询用:group by
distinct 查询多表时,left join 还有效,全连接无效

带符号 * 的表示必填项