使用SQL语句，可以轻松修改SQL主键，下面就将为您介绍这种修改SQL主键的方法，供您参考，希望对您学习修改SQL主键方面有所启迪。

declare @defname varchar(100)  
declare @cmd varchar(500)  
declare @tablename varchar(100)  
declare @keyname varchar(100)  
 
Set @tablename='Temp1' 
Set @keyname='id' --需要設置的key,分隔  
 
select @defname= name  
   FROM sysobjects so   
   JOIN sysconstraints sc  
   ON so.id = sc.constid  
   WHERE object_name(so.parent_obj) = @tablename  
   and xtype='PK' 
 
if @defname is not null  
begin  
select @cmd='alter table '+ @tablename+ ' drop constraint '+ @defname  
--print @cmd  
   exec (@cmd)  
 end  
else  
 set @defname='PK_'+@keyname  
 
 
select @cmd='alter table '+ @tablename+ ' ADD constraint '+ @defname +' PRIMARY KEY CLUSTERED('+@keyname+')'  
   exec (@cmd)