從3個表

Question

獲取數據我有3個表

1的顧客 -c_id -c_name

2 Debit_Master -transaction_id -c_id -AMOUNT

3 Credit_Master -transaction_id - c_id -amount

現在我想要數據l ike this：客戶名稱和每個客戶的總金額（貸項金額 - 借項金額）。

我想查詢有兩列1-客戶名稱，2-的合計金額

Answer 1

試試這個SQL語句獲取在我的列表視圖數據：

SELECT 
    Customers.c_name as CustomerName, 
    SUM((CASE 
      WHEN Credit_Master.amount IS NULL THEN 0 
      ELSE Credit_Master.amount END - 
     CASE 
      WHEN Debit_Master.amount IS NULL THEN 0 
      ELSE Debit_Master.amount END)) as TotalAmount 
FROM Customers 
    LEFT JOIN Debit_Master on Customers.c_id = Debit_Master.c_id 
    LEFT JOIN Credit_Master on Customers.c_id = Credit_Master.c_id 
GROUP BY Customers.c_id 

Answer 2

嘗試是這樣的

SELECT Customers.c_name as name , (Credit_Master.amount - Debit_Master.amount) as total FROM Customers JOIN Debit_Master on Customers.c_id=Debit_Master.c_id JOIN Credit_Master on Customers.c_id=Credit_Master.c_id