MS Access-查询表达式中的语法错误（缺少运算符）

Question

SELECT * FROM exclusivity
left join patent on (exclusivity.[Appl_Type]=patent.[Appl_Type] AND exclusivity.[Appl_No]=patent.[Appl_No] AND exclusivity.[Product_No]=patent.[Product_No])
left join products on (exclusivity.[Appl_Type]=products.[Appl_Type] AND exclusivity.[Appl_No]=products.[Appl_No] AND exclusivity.[Product_No]=products.[Product_No]);

以上查询给出语法错误

（表达式中的（运算符）缺少。排他性。[Appl_Type] =专利。[Appl_Type]和排他性。[Appl_No] =专利。[Appl_No]和排他性。[Product_No] =专利。[Product_No]）左联接产品（排他性。[Appl_Type] = products。[Appl_Type] AND排他性。[Appl_No] = products。[Appl_No] AND排他性。[Product_No] = products。[Product_No]）；'

可能是什么原因？

Answer 1

MS Access对联接周围的括号有奇怪的要求：

SELECT *
FROM (exclusivity left join
      patent
      on exclusivity.[Appl_Type] = patent.[Appl_Type] AND
         exclusivity.[Appl_No] = patent.[Appl_No] AND
         exclusivity.[Product_No] = patent.[Product_No]
    ) left join
    products
    on exclusivity.[Appl_Type] = products.[Appl_Type] AND
       exclusivity.[Appl_No] = products.[Appl_No] AND
       exclusivity.[Product_No] = products.[Product_No];