Sql server 删除重复的行并使用重复的行id更新该行

这是一个场景：我的表中有一个重复的行，具有相同的Id、名称等等

1） 我必须找到匹配所有条件的重复行（已完成）

2） 仅当条件匹配时才删除它们

3） 使用已删除记录的id并更新表中的现有行

为此，我创建了一个2临时表。Temp1是包含所有记录的表。Temp2由重复的行组成

IF OBJECT_ID('tempdb..#Temp1') IS NOT NULL
DROP TABLE #Temp1

IF OBJECT_ID('tempdb..#Temp2') IS NOT NULL
DROP TABLE #Temp2    

IF OBJECT_ID('tempdb..#Temp3') IS NOT NULL
DROP TABLE #Temp3    

CREATE Table #Temp1 ( 
Id int,
Name NVARCHAR(64),
StudentNo INT NULL,
ClassCode NVARCHAR(8) NULL, 
Section  NVARCHAR(8) NULL, 
)


INSERT INTO #Temp1 (Id, Name,StudentNo,ClassCode,Section) Values(1,'Joe',123,'A1', 'I')
INSERT INTO #Temp1 (Id, Name,StudentNo,ClassCode,Section) Values(1,'Joe',123,'A1', 'I')
INSERT INTO #Temp1 (Id, Name,StudentNo,ClassCode,Section) Values(2,'Harry',113,'X2', 'H')
INSERT INTO #Temp1 (Id, Name,StudentNo,ClassCode,Section) Values(2,'Harry',113,'X2', 'H')
INSERT INTO #Temp1 (Id, Name,StudentNo,ClassCode,Section) Values(3,'Elle',121,'J1', 'E1')
INSERT INTO #Temp1 (Id, Name,StudentNo,ClassCode,Section) Values(3,'Elle',121,'J1', 'E')
INSERT INTO #Temp1 (Id, Name,StudentNo,ClassCode,Section) Values(8,'Jane',191,'A1', 'E')
INSERT INTO #Temp1 (Id, Name,StudentNo,ClassCode,Section) Values(5,'Silva',811,'S1', 'SE')
INSERT INTO #Temp1 (Id, Name,StudentNo,ClassCode,Section) Values(6,'Juan',411,'S2', 'SE')
INSERT INTO #Temp1 (Id, Name,StudentNo,ClassCode,Section) Values(7,'Carla',431,'S2', 'SE')

;WITH CTE AS (
    select 
ROW_NUMBER() over (partition by Id                                          
                                , StudentNo                                                                                 
                                order by Id, StudentNo)as Duplicate_RowNumber
, * from #Temp1 )

select  t1.Id,t1.Name,t1.StudentNo,t1.Section,t1.ClassCode 
INTO #Temp2 
from CTE as c INNER JOIN #Temp1 as t1 ON t1.Id = c.Id                                           
                                and t1.StudentNo = t1.StudentNo
                                and c.Duplicate_RowNumber >1

-- this will have 6 rows all the duplicates are included 
--select * from #Temp2 


-- this is for output clause 
DECLARE @inserted Table (Id int,
                        Name NVARCHAR(64),
                        StudentNo INT NULL,
                        ClassCode NVARCHAR(8) NULL, 
                        Section  NVARCHAR(8) NULL)


DELETE FROM  #temp1 
OUTPUT deleted.Id , deleted.Name ,deleted.StudentNo ,deleted.ClassCode ,deleted.Section into @inserted
 WHERE EXISTS ( SELECT * FROM #Temp2 as t2 
                                where  #temp1.Id = t2.Id 
                                        and #temp1.Name = t2.Name
                                            and #temp1.StudentNo = t2.StudentNo                                                      
                                            and #temp1.ClassCode = t2.ClassCode
                                            and #temp1.Section = t2.Section)
-- this is to check what is delete so that i can join it and update the table temp1                                         
select * from @inserted

您可以在下面看到，查询不应删除最后两个突出显示的列，因为该部分不匹配。它应该只删除Temp1和Temp2中的匹配条件

场景2：删除Temp1中的重复记录，并使用键将Section和Classcode的数据更新为NULL。这就是我所期望的突出显示为空。

您可以自己运行此查询—只需复制并粘贴即可。

是的，对于场景1，它将删除行，因为问题在本节中

I added this table for references. 

添加了此#temp2表，以便于以后使用

 CREATE Table #Temp2 ( 
 Id int,
 Name Varchar(64),
 StudentNo INT NULL,
 ClassCode Varchar(8) NULL, 
 Section  Varchar(8) NULL, 
 )
IF OBJECT_ID('tempdb..#tmp4') IS NOT NULL
DROP TABLE #tmp4

select  t1.Id,t1.Name,t1.StudentNo,t1.Section,t1.ClassCode, 
Duplicate_RowNumber 
INTO #Duplicatedata 
from CTE as c INNER JOIN #Temp1 as t1 ON t1.Id = c.Id                                           
                            and t1.StudentNo = t1.StudentNo
                            and c.Duplicate_RowNumber >1

select * from #Duplicatedata 

这将同时满足这两个条件，因为#temp 1将同时包含Elle的两行，因为您的加入条件仅在ID和学生号上

为了清晰起见，我添加了行编号列

  Id    Name    StudentNo   Section ClassCode   Duplicate_RowNumber
   1    Joe          123    I         A1                 2
   1    Joe          123    I         A1                 2
   2    Harry        113    H         X2                 2
   2    Harry        113    H         X2                 2
   3    Elle         121    E1        J1                 2
   3    Elle         121    E         J1                 2

由于您的分区是基于学生编号和ID的，所以每个重复的行将有2个或更多的行号

您可以使用此方法删除

select 
ROW_NUMBER() over (partition by Id                                          
                            , StudentNo                                                                                 
                            order by Id, StudentNo, section)as Duplicate_RowNumber
, * into #tmp4 from #Temp1

--You can add section in your order as well for consistency purpose. 
delete   
from #tmp4  
output deleted.id, deleted.Name, deleted.StudentNo, deleted.ClassCode, 
deleted.Section into #Temp2 
where Duplicate_RowNumber > 1 

之后，您似乎希望在最终表中保留一行，并将另一行放入已删除的表中。对于Elle，它将从最终表中删除一行，并只保留一行，因为您的分区不基于节

I added this table for references. 

要确保从最终表格中删除1行，可以使用此选项

DELETE t 
OUTPUT deleted.Id , deleted.Name ,deleted.StudentNo ,deleted.ClassCode 
,deleted.Section into @inserted  FROM    
(select *, row_number() over (Partition by tm.name, tm.studentNo Order by ID, 
StudentNo, section ) rownum  from  #temp1 tm) t
join              #Temp2 t2 on  t.Id = t2.Id 
                                         and t.Name = t2.Name
                                        and t.StudentNo = t2.StudentNo                                                      
                                        and t.ClassCode   =  t2.ClassCode 
                                        and   t.Section =  t2.Section
where t.rownum > 1 

如果您注意到我添加了这个行号，这样它就不会从最后一个表中删除两行，因为Joe和Harry拥有所有匹配的属性，它会删除两行

select * from @inserted

Output you get: 

 Id Name    StudentNo   ClassCode   Section
 3  Elle    121          J1          E1
 2  Harry   113          X2          H
 1  Joe     123          A1          I

最后，您可以用这种方式更新最终表#情景2

 update TMP 
 SET ClassCode = NULL, SECTION = NULL 
 FROM 
#Temp1 TMP 
JOIN @INSERTED I ON TMP.Id = I.Id 
                AND TMP.StudentNo = I.StudentNo 

 SELECT * FROM #Temp1 

最终输出：

 Id Name    StudentNo   ClassCode   Section
 1  Joe     123             NULL    NULL
 2  Harry   113             NULL    NULL
 3  Elle    121             NULL    NULL
 8  Jane    191             A1       E
 5  Silva   811             S1       SE
 6  Juan    411             S2       SE
 7  Carla   431             S2       SE

---

请注意，我只为需要更改的部分添加了脚本和输出，其余部分与您提供的脚本相同

您已经将--“into#Temp2”插入了两次，对吗？请更新您的查询--delete from#tmp4 output deleted.id、deleted.Name、deleted.StudentNo、deleted.ClassCode、deleted.Section到@inserted where Duplicate\u RowNumber>1@user3920526谢谢你提供的信息，我在复制你的脚本时没有意识到这一点。请查看更新