sql FIFO inventory

Create  Table T ( 
ID int  Identity ( . 1 , . 1 ), name VARCHAR ( 50 ), - trade name 
J int ,         - the number of storage 
C int ,         - the number of library 
jdate datetime  - timespan 
) 
 INSERT  INTO T (name, J, C, jdate) SELECT   ' A ' , 100 , 0 , ' 2007-12-01 '  
INSERT  INTO t(name,j,c,jdate) select  'A',200,0,'2008-01-07' 
insert into t(name,j,c,jdate) select  'B',320,0,'2007-12-21' 
insert into t(name,j,c,jdate) select  'A',100,0,'2008-01-15' 
insert into t(name,j,c,jdate) select  'B',90,0,'2008-02-03' 
insert into t(name,j,c,jdate) select  'A',460,0,'2008-02-01' 
insert into t(name,j,c,jdate) select  'A',510,0,'2008-03-01' 
go

create proc wsp 
@name varchar(50),--商品名称 
@cost int         --Sales 
AS  
- to obtain the stock of goods is enough 
DECLARE  @spare  a float  - the remaining inventory 
SELECT  @spare = SUM (J) - SUM (C) from T WHERE name = the @name  
IF ( @spare > = @cost )                         
    the begin  
    - of inventory items are processed according to the warehouse using the FIFO principle date   
     Update T SET C =                                                                                                                       
     Case  When ( SELECT  @cost - ISNULL ( SUM (J), 0)+isnull(sum(c),0) from t where name=@name and jdate<=a.jdate and j!=c)>=0 
     then a.j 
     else                        
        case when (select @cost-isnull(sum(j),0)+isnull(sum(c),0) from t where name=@name and jdate<a.jdate and j!=c)<0 
        then 0 
        else (select @cost-isnull(sum(j),0)+isnull(sum(c),0)+a.c from t where name=@name and jdate<a.jdate and j!=c) 
        end 
     end 
     from t a where name= The @name  and J ! = C 
    End  
the else  
    RAISERROR ( ' insufficient stock ' , 16 , . 1 )    
     return  
Go 


- Test: 

Exec WSP the @name = ' A ' , @cost = 110  
SELECT  *  from T 


- drop Table T 
- - drop wsp proc 

/ * 

(4 rows affected)  
the above mentioned id name JC jdate
----------- --------------------------- ----------------------- ----------- ----------- ----- ------------------
2007-12-01 00 100 100 A. 1: 00: 00.000 
2 2008-01-07 00 A 200 is 200 is: 00: 00.000 
. 3 B 320. 0 2007-12-21 00: 00: 00.000 
. 4 A 100 30 2008-01- 00 15: 00: 00.000 
5           B                                                  90          0           2008-02-03 00:00:00.000 
. 6 A 460 0 2008-02-01 00: 00: 00.000 
. 7 A 510 0 2008-03-01 00: 00: 00.000 

(affected rows. 7) 
* / 















the CREATE  TABLE #tmp 
  (ID int  the IDENTITY ( . 1 , . 1 ),   
  a monovalent decimal ( 18 is , 2 ) the NOT  NULL ,   
  into the library, the number of decimal ( 18 is , 0 ) the NOT  NULL ,   
  has a number of decimal ( 18 is , 0 ) the NOT  NULL  
  ) 
  INSERT  INTO #tmp (Price , into the number of libraries, we have a number of) values ( 1.1 , 50 , 0 ) 
   INSERT  iNTO#tmp (number of monovalent, into the library, has a number of) values ( 1.3 , 30 , 0 ) 
   INSERT  INTO #tmp (number of monovalent, into the library, has a number of) values ( 1.4 , 60 , 0 ) 
   INSERT  INTO #tmp (Price , into the number of libraries, has a number of) values ( for 1.5 , 20 is , 0 ) 
  
      
  SELECT  *  from #tmp   
   
   
  DECLARE  @t  decimal ( 18 is , 0 ) - once the number of libraries 
, @temp  decimal ( 18 is, 0 ) - number of a temporary library monovalent 
  SELECT  @t = 20 is  
  Update #tmp SET  @temp =  
  Case  When  @t > feed quantity Library - has a number 
   then enter the number of the library - has a number of - when the library when a number of balances greater than the number of the unit price, the number of the unit price of this library is the number of balance, this means that the number of stock priced all consumed. 
  the else  @t  - has a number ofWhen the number is less than or equal to the carrying out of the library a number of unit price, then the number of the library is the actual number of outbound 
  End , 
    @t = @t - @temp , - minus time out for a temporary unit price number library 
   have a number = @temp +- the number of new library of a number of previous libraries + 
   where is the number <> feed quantity Library - a monovalent not participate in the library over a library calculated, i.e. the number zero on balance excluded 
   SELECT  *  from #tmp 
    
    
SET  @t = 40  
   Update #tmp SET  @temp =  
   Case  When  @t > feed quantity library - has a number 
    then enter the number of the library - is the number ofHas a number of 
    the else  @t  
   End , 
    @t = @t - @temp , 
   have a number = @temp + has a number 
    WHERE<> Into the library number 
   
   SELECT  *  from #tmp 
   
   Go  
   drop  Table #tmp