SQL Server数据库删除数据集中重复数据实例讲解

declare @InvoiceListMaster table ( ID int identity primary key ,  
 
companyName Nchar(20),  
 
invoiceNumber int,  
 
CustomerNumber int,  
 
rmaNumber int )  
 
insert  @InvoiceListMaster  
 
select N'华为', 1001,100,200  
 
union all  
 
select N'华为', 1001,100,300  
 
union all  
 
select N'华为', 1001,100,301  
 
union all  
 
select N'中兴', 1002, 200,1     
 
union all  
 
select N'中兴', 1002, 200,2  
 
select * from @InvoiceListMaster  
 
DELETE A  
 
from (  
 
select rown = ROW_NUMBER( )over( partition by companyname,  
 
invoicenumber,  
 
customerNumber   
 
order by companyname,  
 
invoicenumber,  
 
customerNumber ),  
 
companyname,  
 
invoicenumber,  
 
customerNumber  
 
from @InvoiceListMaster )a  
 
where exists ( select 1   
 
from ( select rown = ROW_NUMBER( )over( partition by companyname,  
 
invoicenumber,  
 
customerNumber   
 
order by companyname,  
 
invoicenumber,  
 
customerNumber ),  
 
companyname,  
 
invoicenumber,  
 
customerNumber  
 
from @InvoiceListMaster ) b  
 
where b.companyName = a.companyName  
 
and b.invoiceNumber = a.invoiceNumber  
 
and b.CustomerNumber = a.CustomerNumber  
 
and a.rown > b.rown  
 
)  
 
select * from @InvoiceListMaster