刪除sqlserver中的重複記錄並按照條件儲存其中一條

實施代碼如下：

代碼如下

複製代碼

SELECT * FROM [extract].[dbo].[tbTradeFullinfoGet] WHERE tid IN (SELECT tid FROM [extract].[dbo].[tbTradeFullinfoGet] GROUP BY tid HAVING COUNT(tid) > 1 ) order by tid desc select distinct tid,*  into #aaa from [extract].[dbo].[tbTradeFullinfoGet] truncate table [extract].[dbo].[tbTradeFullinfoGet] insert [extract].[dbo].[tbTradeFullinfoGet] select * from #aaa delete from [extract].[dbo].[tbTradeFullinfoGet] where tid in (select tid from [extract].[dbo].[tbTradeFullinfoGet] group by tid having count(tid) > 1) and intime not in (select max(intime) from [extract].[dbo].[tbTradeFullinfoGet] group by tid having count(tid )>1) select a.*, ROW_NUMBER() over (partition by a.tid order by a.intime desc) as rows_id into   ##test_a from   [extract].[dbo].[tbTradeFullinfoGet] a delete from ##test_a where  rows_id<>'1' alter table ##test_a drop column rows_id drop table [extract].[dbo].[tbTradeFullinfoGet] select * into   [extract].[dbo].[tbTradeFullinfoGet] from   ##test_a

代碼的功能是刪除tbTradeFullinfoGet裡重複的記錄，且只儲存表中intime最大的一條記錄！

其它一些重複資料刪除記錄sql語句

1、SQL Server尋找表中多餘的重複記錄，重複記錄是根據單個欄位（peopleId）來判斷

代碼如下	複製代碼
select * from people  where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)

2、刪除表中多餘的重複記錄，重複記錄是根據單個欄位（peopleId）來判斷，只留有rowid最小的記錄

代碼如下	複製代碼
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、尋找表中多餘的重複記錄（多個欄位）

代碼如下	複製代碼
select * from vitae a  where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)

4、刪除表中多餘的重複記錄（多個欄位），只留有rowid最小的記錄

代碼如下	複製代碼
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、SQL Server尋找表中多餘的重複記錄（多個欄位），不包含rowid最小的記錄

代碼如下	複製代碼
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)

補充一些知識

有兩個意義上的重複記錄，一是完全重複的記錄，也即所有欄位均重複的記錄，二是部分關鍵字段重複的記錄，比如Name欄位重複，而其他欄位不一定重複或都重複可以忽略。
1、對於第一種重複，比較容易解決，使用

代碼如下	複製代碼
select distinct * from tableName

就可以得到無重複記錄的結果集。
如果該表需要重複資料刪除的記錄（重複記錄保留1條），可以按以下方法刪除

代碼如下	複製代碼
select distinct * into #Tmp from tableName drop table tableName select * into tableName from #Tmp drop table #Tmp

發生這種重複的原因是表設計不周產生的，增加唯一索引列即可解決。
2、這類重複問題通常要求保留重複記錄中的第一條記錄，操作方法如下
假設有重複的欄位為Name,Address，要求得到這兩個欄位唯一的結果集

代碼如下	複製代碼
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)

最後一個select即得到了Name，Address不重複的結果集（但多了一個autoID欄位，實際寫時可以寫在select子句中省去此列）
3、部分關鍵字段重複，且記錄中有ID.
第一種方法可一次刪除所有重複的..(只保留重複中ID最小的記錄)。

代碼如下	複製代碼
delete from table where id not in ( select min(id) from table group by name)

第二種方法每次只重複資料刪除中ID最大的一條記錄。

代碼如下	複製代碼
delete from table where id in ( select max(id) from table group by name having count(*)>1)