Question

Category Table have:

- category code
- category name

Items table have:

- category code
- Item Code
- Item Name

Old Table have :

- Category Code
- Old code
- Old Detail

现在我要以格式

显示表格

所有三个表都有相同的类别代码

我使用了这个查询： -

 SELECT dbo.N_items.CategoryCode, dbo.N_items.ItemCode AS [New Code], dbo.N_items.ItemDetail AS [New Detail], dbo.OldMasterTable.OldItemCode AS [Old Code],   dbo.OldMasterTable.OldItemDetails AS [Old Detail]
FROM   dbo.OldMasterTable INNER JOIN  dbo.N_items 
ON dbo.N_items.CategoryCode = dbo.OldMasterTable.CategoryCode

但项目细节表正在重复

Answer 1

尝试使用GROUP BY，也使用别名来轻松：

SELECT C.CategoryCode, 
       I.ItemCode AS [New Code], 
       I.ItemDetail AS [New Detail], 
       O.OldItemCode AS [Old Code], 
       O.OldItemDetails AS [Old Detail]
FROM Category C JOIN
     Items I ON C.CategoryCode=I.CategoryCode JOIN
     OldMasterTable O ON C.CategoryCode=O.CategoryCode
GROUP BY C.CategoryCode, I.ItemCode AS [New Code], 
         I.ItemDetail AS [New Detail], O.OldItemCode AS [Old Code], 
         O.OldItemDetails AS [Old Detail]

Answer 2

尝试以下解决方案 - 它不会重复项目表详细信息。在加入之前先保留项目表。希望它能解决你的问题。

SELECT c.CategoryCode, c.CategoryName, i.ItemCode, i.ItemName, o.OldItemCode, o.OldItemDetails
FROM  Items i 
LEFT JOIN CategoryTable c on i.CategoryCode = c.CategoryCode
LEFT JOIN OldMasterTable o ON i.CategoryCode = o.CategoryCode

使用连接的SQL查询

2 个答案: