Question

我需要渲染下表，以便现在客户支付了多少汉堡

客户|汉堡1数量|汉堡2数量|

我有两张桌子：

客户表：使用CustomerID，名称
交易订单：使用TransactionOrderID CustomerID和BurgerCode

我有6个汉堡代码，每个我需要添加一个列，最好的方法是什么？

Answer 1

如果你不想使用支点，你可以尝试这样的事情。

   WITH cte AS
   ( 
   SELECT 
       CustomerID,
       SUM(CASE WHEN BurgerCode LIKE 'BurgerCode1' THEN 1 ELSE 0 END) AS Burger1Qty,
       SUM(CASE WHEN BurgerCode LIKE 'BurgerCode2' THEN 1 ELSE 0 END) AS Burger2Qty,
       SUM(CASE WHEN BurgerCode LIKE 'BurgerCode3' THEN 1 ELSE 0 END) AS Burger3Qty,
       SUM(CASE WHEN BurgerCode LIKE 'BurgerCode4' THEN 1 ELSE 0 END) AS Burger4Qty,
       SUM(CASE WHEN BurgerCode LIKE 'BurgerCode5' THEN 1 ELSE 0 END) AS Burger5Qty,
       SUM(CASE WHEN BurgerCode LIKE 'BurgerCode6' THEN 1 ELSE 0 END) AS Burger6Qty
    FROM TransactionOrders
    GROUP BY CustomerID
    )
    SELECT c.*, ct.Name CustomerName FROM cte c JOIN CustomerTable ct ON ct.CustomerID = c.CustomerID

SQL计算客户的特定项目

1 个答案: