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MySQL²éѯ±íÄÚÖظ´¼Ç¼
 
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1¡¢²éÕÒ±íÖжàÓàµÄÖظ´¼Ç¼£¬Öظ´¼Ç¼ÊǸù¾Ýµ¥¸ö×ֶΣ¨peopleId£©À´ÅжÏ
select * from people
where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)
2¡¢É¾³ý±íÖжàÓàµÄÖظ´¼Ç¼£¬Öظ´¼Ç¼ÊǸù¾Ýµ¥¸ö×ֶΣ¨peopleId£©À´Åжϣ¬Ö»ÁôÓÐrowid×îСµÄ¼Ç¼
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¡¢²éÕÒ±íÖжàÓàµÄÖظ´¼Ç¼£¨¶à¸ö×ֶΣ©
select * from vitae a
where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)
4¡¢É¾³ý±íÖжàÓàµÄÖظ´¼Ç¼£¨¶à¸ö×ֶΣ©£¬Ö»ÁôÓÐrowid×îСµÄ¼Ç¼
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¡¢²éÕÒ±íÖжàÓàµÄÖظ´¼Ç¼£¨¶à¸ö×ֶΣ©£¬²»°üº¬rowid×îСµÄ¼Ç¼
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)
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±È·½Ëµ
ÔÚA±íÖдæÔÚÒ»¸ö×ֶΓname”£¬
¶øÇÒ²»Í¬¼Ç¼֮¼äµÄ“name”ÖµÓпÉÄÜ»áÏàͬ£¬
ÏÖÔÚ¾ÍÊÇÐèÒª²éѯ³öÔڸñíÖеĸ÷¼Ç¼֮¼ä£¬“name”Öµ´æÔÚÖظ´µÄÏ
Select Name,Count(*) from A Group By Name Having Count(*) > 1
Èç¹û»¹²éÐÔ±ðÒ²Ïàͬ´óÔòÈçÏÂ:
Select Name,sex,Count(*) from A Group By Name,sex Having Count(*) > 1
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declare @max integer,@id integer
declare cur_rows cursor local for select Ö÷×Ö¶Î,count(*) from ±íÃû group by Ö÷×ֶΠhaving count(*) >£» 1
open cur_rows
fetch cur_rows into @id,@max
while @@fetch_status=0
begin
select @max = @max -1
set rowcount @max
delete from ±íÃû where Ö÷×ֶΠ= @id
fetch cur_rows into @id,@max
end
close c