MySQL根据某一个或者多个字段查找重复数据的sql语句

 select * from xi a where (a.username) in (select username from xi group by username having count(*) > 1)

 select count(username) as '重复次数',username from xi group by username having count(*)>1 order by username desc

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

 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)

 select * from vitae a
where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)

 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)

 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)

 Select Name,Count(*) From A Group By Name Having Count(*) > 1

 Select Name,sex,Count(*) From A Group By Name,sex Having Count(*) > 1

declare @max integer,@id integer
declare cur_rows cursor local for 
select 主字段,count(*) from 表名 group by 主字段 having count(*) >;
open cur_rows fetch cur_rows into @id,@maxwhile @@fetch_status=0
begin
 select @max = @max -1
 set rowcount @max
 delete from 表名 where 主字段 = @id
fetch cur_rows into @id,@maxend
close cur_rows
set rowcount 0

 select distinct * from tableName

 select distinct * into #Tmp from tableName
drop table tableName
select * into tableName from #Tmp
drop table #Tmp

 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)　

 select * from tablename where id in (select id from tablenamegroup by idhaving count(id) > 1)

SELECT * FROM tb_table WHERE sample_code IN( SELECT sample_code FROM tb_table GROUP BY sample_code HAVING COUNT(sample_code) > 1 );

SELECT * from (SELECT *, CONCAT(name,code) as nameAndCode from tb_table) t WHERE t.nameAndCode in 
(
 SELECT nameAndCode from (SELECT CONCAT(name,code) as nameAndCode from tb_table) tt GROUP BY nameAndCode HAVING count(nameAndCode) > 1
)