将 MS 访问计数和数据透视查询转换为 SQL 服务器

Question

我有杂货店数据库。我想计算收据上每个类别的产品数量。

表格是：

Transactions（id_transaction，数量，id_receipt，id_product）
Receipts (id_receipt, 日期, id_store, id_customer)
Products (id_product, product_name, 价格, id_prod_cat)
Product_Categories (id_prod_cat, category_name)

带有示例数据的所需输出：

ID_RECEIPT |   desserts | meat |   juices | baker products| canned |
-------------------------------------------------------------------|
1          |   0        |   2  |    1     |     3         |   0    |
2          |   1        |   0  |    3     |     1         |   0    |
--------------------------------------------------------------------

我试过这个查询但没有成功。

TRANSFORM Nz(Count(dbo.Transactions.quantity), 0) AS Product Count 
SELECT dbo.Receipts.id_receipt 
FROM dbo.Product_Categories 
INNER JOIN (dbo.Receipts 
   INNER JOIN (dbo.PRODUCTS 
      INNER JOIN dbo.TRANSACTIONS ON dbo.PRODUCTS.id_product = dbo.TRANSACTIONS.id_product) 
      ON dbo.RECEIPTS.id_receipt = dbo.TRANSACTIONS.id_receipt)  
   ON dbo.Product_Categories.id_prod_cut = dbo.Products.id_product 
GROUP BY 
    dbo.Receipts.id_receipt 
PIVOT 
    dbo.Product_Categories.category_name

Answer 1

本质上，这是经典的转置查询。考虑以下 SQL，它应该符合大多数 RDMS。对于 MS Access，您将使用 IIF() 而不是 CASE WHEN（以及连接中的括号）。 Transform 的交叉表查询主要是 MS Access 类型，而 Pivot() 主要是 SQL 服务器功能。但是，下面应该跨数据库方言工作。

SELECT 
    dbo.Receipts.id_receipt,
    Count(CASE WHEN dbo.Product_Categories.category_name='desserts' 
               THEN dbo.Transactions.quantity END) As [desserts],
    Count(CASE WHEN dbo.Product_Categories.category_name='meat' 
               THEN dbo.Transactions.quantity END) As [meat],
    Count(CASE WHEN dbo.Product_Categories.category_name='juices' 
               THEN dbo.Transactions.quantity END) As [juices],
    Count(CASE WHEN dbo.Product_Categories.category_name='baker products' 
               THEN dbo.Transactions.quantity END) As [baker products],
    Count(CASE WHEN dbo.Product_Categories.category_name='canned' 
               THEN dbo.Transactions.quantity END) As [canned]

FROM dbo.Product_Categories
INNER JOIN dbo.Receipts 
INNER JOIN dbo.PRODUCTS 
INNER JOIN dbo.TRANSACTIONS ON dbo.PRODUCTS.id_product = dbo.TRANSACTIONS.id_product 
     ON dbo.RECEIPTS.id_receipt = dbo.TRANSACTIONS.id_receipt
     ON dbo.Product_Categories.id_prod_cut = dbo.Products.id_product 

GROUP BY dbo.Receipts.id_receipt ;

将 MS 访问计数和数据透视查询转换为 SQL 服务器

Convert MS Access count and pivot query into SQL Server

sql-server

ms-access

pivot-table

count