1、sql 查詢重復記錄方法大全(2010-12-03 16:14:01)標簽： 分類： SQL Server雜談查找所有重復標題的記錄：SELECT *FROM t_info aWHERE (SELECT COUNT(*)FROM t_infoWHERE Title = a.Title) > 1)ORDER BY Title DESC一。查找重復記錄1。查找全部重復記錄Select * From 表 Where 重復字段 In (Select 重復字段 From 表 Group By 重復字段 Having Count(*)>1) 2。過濾重復記錄 （只顯示一條 ）Select *

2、From HZT Where ID In (Select Max(ID) From HZT Group By Title) 注：此處顯示 ID 最大一條記錄二。刪除重復記錄1。刪除全部重復記錄（慎用）Delete 表 Where 重復字段 In (Select 重復字段 From 表 Group By 重復字段 Having Count(*)>1)2。保留一條（這個應該是大多數人所需要的A A)Delete HZT Where ID Not In (Select Max(ID) From HZT Group By Title)注：此處保留 ID 最大一條記錄1、查找表中多余的重復記錄，重

3、復記錄是根據單個字段（peop leld)來判斷select * from peoplewhere peopleId in (select peopleId from people group bypeopleId having count(peopleId) > 1)2、刪除表中多余的重復記錄，重復記錄是根據單個字段（peopleld）來判斷，只留有 rowid最小的記錄delete from peoplewhere peopleId in (select peopleId from people group by peopleId having count(peopleId) >

4、; 1)and rowid not in (select min(rowid) from people group by peopleId having count(peopleId )>1)3、查找表中多余的重復記錄多個字段）select * from vitae awhere (a.peopleId,a.seq) in(select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)4、刪除表中多余的重復記錄多個字段），只留有rowid 最小的記錄delete from vitae awhere

5、(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、查找表中多余的重復記錄（多個字段），不包含rowid 最小的記錄select * from vitae a where (a.peopleId,a.seq) in (select peopleId,seq from vi

6、tae group by peopleId,seq having count(*) > 1) and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>1)補充：有兩個以上的重復記錄，一是完全重復的記錄，也即所有字段均重復的記錄，二是部分關鍵字段重復的記 錄，比如 Name 字段重復，而其他字段不一定重復或都重復可以忽略。1、對于第一種重復，比較容易解決，使用 select distinct * from tableName就可以得到無重復記錄的結果集。如果該表需要刪除重

7、復的記錄（重復記錄保留1 條），可以按以下方法刪除 select distinct * into #Tmp from tableName drop table tableName select * into tableName from #Tmpdrop table #Tmp發生這種重復的原因是表設計不周產生的，增加唯一索引列即可解決。2、這類重復問題通常要求保留重復記錄中的第一條記錄，操作方法如下假設有重復的字段為 Name,Address，要求得到這兩個字段唯一的結果集 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