Question

我有一个以事务为事实表的星型模式。

对于每个产品列表，麦迪逊供应商向芝加哥消费者的销售数量与芝加哥供应商向麦迪逊消费者的销售数量（结果列：产品名称，麦迪逊芝加哥数量，芝加哥麦迪逊数量）

我已经尝试过相交和结合所有

SELECT 
    P.Name as Product
   , SUM(T.Quantity) as QMad
   , dbo.Tb_Consumer C
   , dbo.Tb_Supplier S
   , dbo.Tb_Transactions T
   where P.Prod_ID = T.Prod_ID
   and C.Con_ID = T.Con_ID
   and S.Supp_ID = T.Supp_ID
   and S.City = 'Madison'
   and C.City = 'Chicago'
  from dbo.Tb_Product P
  group by P.Name
  union all
  SELECT P.Name as Product
  , sum(T.Quantity) as QCHI
  from dbo.Tb_Product P
  , dbo.Tb_Consumer C
  ,dbo.Tb_Supplier S
  ,dbo.Tb_Transactions T
  where P.Prod_ID = T.Prod_ID
  and C.Con_ID = T.Con_ID
  and S.Supp_ID = T.Supp_ID
  and S.City = 'Chicago'
  and C.City = 'Madison'
  group by P.Name

期待以下内容

Product   chi_qy   Mad_qy
-------------------------
Auto       3        2

但我明白了

Product   chi_qy    
----------------- 
Auto       3        
Auto       2

Answer 1

只连接两个查询而不是联合像这样：

select X.Product,QMad,QCHI
from(
SELECT 
    P.Name as Product
   , SUM(T.Quantity) as QMad
   from dbo.Tb_Product P
   , dbo.Tb_Consumer C
   , dbo.Tb_Supplier S
   , dbo.Tb_Transactions T
   where P.Prod_ID = T.Prod_ID
   and C.Con_ID = T.Con_ID
   and S.Supp_ID = T.Supp_ID
   and S.City = 'Madison'
   and C.City = 'Chicago'
  from dbo.Tb_Product P
  group by P.Name) X
inner join
  (SELECT P.Name as Product
  , sum(T.Quantity) as QCHI
  from dbo.Tb_Product P
  , dbo.Tb_Consumer C
  ,dbo.Tb_Supplier S
  ,dbo.Tb_Transactions T
  where P.Prod_ID = T.Prod_ID
  and C.Con_ID = T.Con_ID
  and S.Supp_ID = T.Supp_ID
  and S.City = 'Chicago'
  and C.City = 'Madison'
  group by P.Name) Y on X.Product=Y.Product

如果每边都为空白，则可以使用left，right或完全外部联接

我需要针对星型模式编写SQL，在星型模式中，我的产品与供应商在一个城市，而消费者在另一个城市，反之亦然

1 个答案: