手机推荐排行榜,耳根

主頁 > 知識庫 > sql分組后二次匯總(處理表重復(fù)記錄查詢和刪除)的實(shí)現(xiàn)方法

sql分組后二次匯總(處理表重復(fù)記錄查詢和刪除)的實(shí)現(xiàn)方法

--處理表重復(fù)記錄(查詢和刪除)
/******************************************************************************************************************************************************
1、Num、Name相同的重復(fù)值記錄,沒有大小關(guān)系只保留一條
2、Name相同,ID有大小關(guān)系時(shí),保留大或小其中一個(gè)記錄
整理人：中國風(fēng)(Roy)

日期:2008.06.06
******************************************************************************************************************************************************/

--1、用于查詢重復(fù)處理記錄(如果列沒有大小關(guān)系時(shí)2000用生成自增列和臨時(shí)表處理,SQL2005用row_number函數(shù)處理)

--> --> (Roy)生成測試數(shù)據(jù)

if not object_id('Tempdb..#T') is null
 drop table #T
Go
Create table #T([ID] int,[Name] nvarchar(1),[Memo] nvarchar(2))
Insert #T
select 1,N'A',N'A1' union all
select 2,N'A',N'A2' union all
select 3,N'A',N'A3' union all
select 4,N'B',N'B1' union all
select 5,N'B',N'B2'
Go

--I、Name相同ID最小的記錄(推薦用1,2,3),方法3在SQl05時(shí)，效率高于1、2
方法1:
Select * from #T a where not exists(select 1 from #T where Name=a.Name and IDa.ID)

方法2:
select a.* from #T a join (select min(ID)ID,Name from #T group by Name) b on a.Name=b.Name and a.ID=b.ID

方法3:
select * from #T a where ID=(select min(ID) from #T where Name=a.Name)

方法4:
select a.* from #T a join #T b on a.Name=b.Name and a.ID>=b.ID group by a.ID,a.Name,a.Memo having count(1)=1

方法5:
select * from #T a group by ID,Name,Memo having ID=(select min(ID)from #T where Name=a.Name)

方法6:
select * from #T a where (select count(1) from #T where Name=a.Name and IDa.ID)=0

方法7:
select * from #T a where ID=(select top 1 ID from #T where Name=a.name order by ID)

方法8:
select * from #T a where ID!>all(select ID from #T where Name=a.Name)

方法9(注:ID為唯一時(shí)可用):
select * from #T a where ID in(select min(ID) from #T group by Name)

--SQL2005:

方法10:
select ID,Name,Memo from (select *,min(ID)over(partition by Name) as MinID from #T a)T where ID=MinID

方法11:

select ID,Name,Memo from (select *,row_number()over(partition by Name order by ID) as MinID from #T a)T where MinID=1

生成結(jié)果:
/*
ID          Name Memo
----------- ---- ----
1           A    A1
4           B    B1

(2 行受影響)
*/

--II、Name相同ID最大的記錄,與min相反:
方法1:
Select * from #T a where not exists(select 1 from #T where Name=a.Name and ID>a.ID)

方法2:
select a.* from #T a join (select max(ID)ID,Name from #T group by Name) b on a.Name=b.Name and a.ID=b.ID order by ID

方法3:
select * from #T a where ID=(select max(ID) from #T where Name=a.Name) order by ID

方法4:
select a.* from #T a join #T b on a.Name=b.Name and a.ID=b.ID group by a.ID,a.Name,a.Memo having count(1)=1

方法5:
select * from #T a group by ID,Name,Memo having ID=(select max(ID)from #T where Name=a.Name)

方法6:
select * from #T a where (select count(1) from #T where Name=a.Name and ID>a.ID)=0

方法7:
select * from #T a where ID=(select top 1 ID from #T where Name=a.name order by ID desc)

方法8:
select * from #T a where ID!all(select ID from #T where Name=a.Name)

方法9(注:ID為唯一時(shí)可用):
select * from #T a where ID in(select max(ID) from #T group by Name)

--SQL2005:

方法10:
select ID,Name,Memo from (select *,max(ID)over(partition by Name) as MinID from #T a)T where ID=MinID

方法11:
select ID,Name,Memo from (select *,row_number()over(partition by Name order by ID desc) as MinID from #T a)T where MinID=1

生成結(jié)果2:
/*
ID          Name Memo
----------- ---- ----
3           A    A3
5           B    B2

(2 行受影響)
*/

--2、刪除重復(fù)記錄有大小關(guān)系時(shí),保留大或小其中一個(gè)記錄

--> --> (Roy)生成測試數(shù)據(jù)

if not object_id('Tempdb..#T') is null
drop table #T
Go
Create table #T([ID] int,[Name] nvarchar(1),[Memo] nvarchar(2))
Insert #T
select 1,N'A',N'A1' union all
select 2,N'A',N'A2' union all
select 3,N'A',N'A3' union all
select 4,N'B',N'B1' union all
select 5,N'B',N'B2'
Go

--I、Name相同ID最小的記錄(推薦用1,2,3),保留最小一條
方法1:
delete a from #T a where exists(select 1 from #T where Name=a.Name and IDa.ID)

方法2:
delete a from #T a left join (select min(ID)ID,Name from #T group by Name) b on a.Name=b.Name and a.ID=b.ID where b.Id is null

方法3:
delete a from #T a where ID not in (select min(ID) from #T where Name=a.Name)

方法4(注:ID為唯一時(shí)可用):
delete a from #T a where ID not in(select min(ID)from #T group by Name)

方法5:
delete a from #T a where (select count(1) from #T where Name=a.Name and IDa.ID)>0

方法6:
delete a from #T a where ID>(select top 1 ID from #T where Name=a.name order by ID)

方法7:
delete a from #T a where ID>any(select ID from #T where Name=a.Name)

select * from #T

生成結(jié)果:
/*
ID          Name Memo
----------- ---- ----
1           A    A1
4           B    B1

(2 行受影響)
*/

--II、Name相同ID保留最大的一條記錄:

方法1:
delete a from #T a where exists(select 1 from #T where Name=a.Name and ID>a.ID)

方法2:
delete a from #T a left join (select max(ID)ID,Name from #T group by Name) b on a.Name=b.Name and a.ID=b.ID where b.Id is null

方法3:
delete a from #T a where ID not in (select max(ID) from #T where Name=a.Name)

方法4(注:ID為唯一時(shí)可用):
delete a from #T a where ID not in(select max(ID)from #T group by Name)

方法5:
delete a from #T a where (select count(1) from #T where Name=a.Name and ID>a.ID)>0

方法6:
delete a from #T a where ID>(select top 1 ID from #T where Name=a.name order by ID desc)

方法7:
delete a from #T a where IDany(select ID from #T where Name=a.Name)

select * from #T
/*
ID          Name Memo
----------- ---- ----
3           A    A3
5           B    B2

(2 行受影響)
*/

--3、刪除重復(fù)記錄沒有大小關(guān)系時(shí)，處理重復(fù)值

--> --> (Roy)生成測試數(shù)據(jù)

if not object_id('Tempdb..#T') is null
drop table #T
Go
Create table #T([Num] int,[Name] nvarchar(1))
Insert #T
select 1,N'A' union all
select 1,N'A' union all
select 1,N'A' union all
select 2,N'B' union all
select 2,N'B'
Go

方法1:
if object_id('Tempdb..#') is not null
drop table #
Select distinct * into # from #T--排除重復(fù)記錄結(jié)果集生成臨時(shí)表#

truncate table #T--清空表

insert #T select * from # --把臨時(shí)表#插入到表#T中

--查看結(jié)果
select * from #T

/*
Num         Name
----------- ----
1           A
2           B

(2 行受影響)
*/

--重新執(zhí)行測試數(shù)據(jù)后用方法2
方法2:

alter table #T add ID int identity--新增標(biāo)識列
go
delete a from #T a where exists(select 1 from #T where Num=a.Num and Name=a.Name and ID>a.ID)--只保留一條記錄
go
alter table #T drop column ID--刪除標(biāo)識列

--查看結(jié)果
select * from #T

/*
Num         Name
----------- ----
1           A
2           B

(2 行受影響)

--重新執(zhí)行測試數(shù)據(jù)后用方法3
方法3:
declare Roy_Cursor cursor local for
select count(1)-1,Num,Name from #T group by Num,Name having count(1)>1
declare @con int,@Num int,@Name nvarchar(1)
open Roy_Cursor
fetch next from Roy_Cursor into @con,@Num,@Name
while @@Fetch_status=0
begin
    set rowcount @con;
    delete #T where Num=@Num and Name=@Name
    set rowcount 0;
    fetch next from Roy_Cursor into @con,@Num,@Name
end
close Roy_Cursor
deallocate Roy_Cursor

--查看結(jié)果
select * from #T
/*
Num         Name
----------- ----
1           A
2           B

(2 行受影響)

您可能感興趣的文章:

SQL SERVER 分組求和sql語句
顯示同一分組中的其他元素的sql語句
sql獲取分組排序后數(shù)據(jù)的腳本
SQL進(jìn)行排序、分組、統(tǒng)計(jì)的10個(gè)新技巧分享
SQL分組排序去重復(fù)的小實(shí)例
以數(shù)據(jù)庫字段分組顯示數(shù)據(jù)的sql語句(詳細(xì)介紹)
SQL中Group分組獲取Top N方法實(shí)現(xiàn)可首選row_number
Sql Server：多行合并成一行，并做分組統(tǒng)計(jì)的兩個(gè)方法
Sql Server 分組統(tǒng)計(jì)并合計(jì)總數(shù)及WITH ROLLUP應(yīng)用
SQL語句分組獲取記錄的第一條數(shù)據(jù)的方法
sqlserver巧用row_number和partition by分組取top數(shù)據(jù)
一句Sql把縱向表轉(zhuǎn)為橫向表，并分別分組求平均和總平均值
sql 分組查詢問題
SQLserver 實(shí)現(xiàn)分組統(tǒng)計(jì)查詢（按月、小時(shí)分組）
分組后分組合計(jì)以及總計(jì)SQL語句（稍微整理了一下）

標(biāo)簽：東營新鄉(xiāng) 來賓黃山池州文山濱州大同

巨人網(wǎng)絡(luò)通訊聲明：本文標(biāo)題《sql分組后二次匯總(處理表重復(fù)記錄查詢和刪除)的實(shí)現(xiàn)方法》，本文關(guān)鍵詞 sql,分組,后,二次,匯總,處理,；如發(fā)現(xiàn)本文內(nèi)容存在版權(quán)問題，煩請?zhí)峁┫嚓P(guān)信息告之我們，我們將及時(shí)溝通與處理。本站內(nèi)容系統(tǒng)采集于網(wǎng)絡(luò)，涉及言論、版權(quán)與本站無關(guān)。