SQLSERVER2000中表变量的应用
原语句如下
1 declare @d datetime 2 set @d=getdate() 3 SELECT [P_ID] FROM [ProductInfo] 4 WHERE [P_ID] IN 5 (28674,28667,28241,355,7210,14646,2164,11891,4519,14671,21788,21816,21817,21108,21196) 6 select [语句执行花费时间(毫秒)]=datediff(ms,@d,getdate())
现要求按括号中的ID顺序输出结果
此时, 可以用到SQLSERVER2000 以上版本中特有的表变量(table)(亦可用临时表,但性能还是有不小的差距)
结果语句如下:
1 declare @d2 datetime 2 set @d2=getdate() 3 declare @list Nvarchar(4000) 4 declare @str Nvarchar(10) 5 declare @orderid int 6 declare @tmp int 7 8 Declare @TableVar Table (OrderID int Primary Key ,TestID int) 9 10 set @list='28674,28667,28241,355,7210,14646,2164,11891,4519,14671,21788,21816,21817,21108,21196' 11 set @orderid=0 12 while (charindex(',',@list)>0) 13 begin 14 15 set @str=substring(@list,1,charindex(',',@list)) 16 print @str 17 set @tmp= cast(Replace(@str,',','') as int) 18 print @tmp 19 set @list=substring(@list,len(@str)+1,len(@list)-len(@str)+1) 20 ----set @str=Replace(@str,',','') 21 set @orderid=@orderid+1 22 print @orderid 23 Insert Into @TableVar Values (@orderid, @tmp) 24 end 25 26 -- Select TestID From @TableVar order by OrderID 27 28 29 select [P_ID] from productinfo p 30 inner join @TableVar a 31 on p.p_ID=a.TestID 32 order by a.OrderID 33 34 select [语句执行花费时间(毫秒)]=datediff(ms,@d2,getdate())