一些实用SQL语句

1. 取10--20条记录 

select news_id from Item_T_Info_News 
where news_id>=(select  max(t1.News_ID) from (select top 10 * from Item_T_Info_News order by News_ID) as t1) 
and news_id<=(select  max(t2.News_ID) from (select top 20 * from Item_T_Info_News order by News_ID) as t2)

2. 表变量和临时表的定义

表变量

DECLARE @indextable table
(
    uid int identity(1,1),    
    id int
)

临时表

CREATE Table #temptable
(
    id int,
    date datetime        
)

当数据量大时,建议使用临时表!

3. 错开排序 

declare @t table(empid int,empname varchar(10),deptid int)
insert into @t select 1,'员工A',5
insert into @t select 2,'员工B',5
insert into @t select 3,'员工C',7
insert into @t select 4,'员工D',7
insert into @t select 5,'员工E',9
insert into @t select 6,'员工F',5
insert into @t select 7,'员工G',7
insert into @t select 8,'员工H',9
insert into @t select 9,'员工I',3

select px=(select count(1) from @t where deptid=a.deptid and empid<=a.empid),* from @t a
order by px,deptid 

4. 统计某一产品出现的次数

declare @myTable table
(
　　pro_ID int,
　　pro_count int
)
insert into @myTable(pro_ID,pro_count) 
select OrderPro_ProID,count(OrderPro_ProID) from Item_T_Order_OrderPro
group by OrderPro_ProID
select * from @myTable

5. 按in的顺序排序

select * from Item_T_Pro_Product 
where Pro_ID in(90,153,158,80,76,98,96,85,101,104)
ORDER BY 
charindex(','+cast(Pro_ID as varchar(10))+',', ',90,153,158,80,76,98,96,85,101,104,')

6. split函数

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
go

ALTER FUNCTION [dbo].[split]
 (@str nvarchar(4000),@code varchar(10),@no int )  
RETURNS varchar(200)
AS  
BEGIN
declare @intLen int
declare @count int
declare @indexb  int
declare @indexe  int
set @intLen=len(@code)
set @count=0
set @indexb=1

if @no=0
  if charindex(@code,@str,@indexb)<>0
     return left(@str,charindex(@code,@str,@indexb)-1) 
  else
     return @str
while charindex(@code,@str,@indexb)<>0
  begin
       set @count=@count+1
       if @count=@no
         break
       set @indexb=@intLen+charindex(@code,@str,@indexb)
  end

if @count=@no
begin
      set @indexe=@intLen+charindex(@code,@str,@indexb)
          if charindex(@code,@str,@indexe)<>0
             return substring(@str,charindex(@code,@str,@indexb)+len(@code),charindex(@code,@str,@indexe)-charindex(@code,@str,@indexb)-len(@code))
          else 
             return right(@str,len(@str)-charindex(@code,@str,@indexb)-len(@code)+1)
  end
return ''
END

Code