清单 SQL 查询出现歧义错误，其中两个字段应该相等才能进行计算。访问权限

Question

有了 this simple group of tables，我想制作一份清单来区分来自不同供应商的相同产品，但我收到了一个 "ambiguity error" 运行查询，虽然它会工作。我不知道如何解决这个问题。

这是我试过的查询：

SELECT tblProducts.product_Name, 
       tblProviders.provider, 
       Nz(Sum(tblIntakes.intake_QTY),0)-
       Nz(Sum(tblExits.exit_QTY)) AS Stock

FROM tblProviders, 
     (tblProducts LEFT JOIN 
     tblExits 
     ON tblProducts.product_ID = tblExits.product_ID
     ) LEFT JOIN 
     tblIntakes 
     ON tblProducts.product_ID = tblIntakes.product_ID

GROUP BY tblProducts.product_Name, tblProviders.provider;

Answer 1

您可以在这种情况下使用子查询：

SELECT
  tblProducts.product_Name,
  tblProviders.provider,
  Nz((
    SELECT SUM(intake_QTY)
    FROM tblIntakes
    WHERE
      tblIntakes.product_ID = tblProducts.product_ID AND
      tblIntakes.provider_ID = tblProviders.provider_ID
  ), 0) -
  Nz((
    SELECT SUM(exit_QTY)
    FROM tblExits
    WHERE
      tblExits.product_ID = tblProducts.product_ID AND
      tblExits.provider_ID = tblProviders.provider_ID
  ), 0) AS Stock
FROM tblProviders, tblProducts;

清单 SQL 查询出现歧义错误，其中两个字段应该相等才能进行计算。访问权限

Getting ambiguity error for a inventory SQL query where two fields should be equal to make the calculation. MS-ACCESS

sql

database

ms-access

join

inventory