大力的先入先出的库存物品，按批次出货的问题的一个解法。-数据库专栏,SQL Server

create table g (goods varchar(2),lot varchar(3),bal int)
create table o (oid varchar,goods varchar(2),qty int)
insert g select aa,p01,5
   union select aa,p02,10
   union select bb,p01,20

insert o select 1,aa,11
   union select 1,bb,10
   union select 2,aa,2
   union select 3,aa,1

select oid,b.goods,lot,deli=(case when sq>sb then sb else sq end)-(case when sq-qty<sb-bal then sb-bal else sq-qty end)
from ( select *,sq=( select sum(qty) 
                             from o
                             where oid <=a.oid and goods=a.goods
                           )
       from o a
     ) b
     join
     ( select *,sb=( select sum(bal)
                              from g
                              where goods=a.goods and lot<=a.lot
                            )
       from g a
     ) c
     on b.goods=c.goods and sq-qty<sb and sq>sb-bal
order by oid,b.goods,lot

drop table g,o