MySQL多表操作是數據庫開發中常見的應用場景。掌握多表操作可以提高開發效率和數據管理能力。以下是一些MySQL多表操作的試題。

1. 查找所有訂單中商品數量大于等于2個的訂單信息，包括訂單編號、訂單日期、客戶名稱、商品名稱、商品數量。

SELECT Orders.OrderID,Orders.OrderDate,Customers.CustomerName,Products.ProductName,OrderDetails.Quantity
FROM Orders
JOIN Customers ON Orders.CustomerID = Customers.CustomerID
JOIN OrderDetails ON Orders.OrderID = OrderDetails.OrderID
JOIN Products ON OrderDetails.ProductID = Products.ProductID
WHERE OrderDetails.Quantity >= 2;

2. 查找所有訂單中的客戶名稱和訂單數量，按訂單數量從多到少排序。

SELECT Customers.CustomerName,COUNT(Orders.OrderID) AS OrderCount
FROM Customers
LEFT JOIN Orders ON Customers.CustomerID = Orders.CustomerID
GROUP BY Customers.CustomerName
ORDER BY OrderCount DESC;

3. 查找所有未被訂購過的商品名稱。

SELECT Products.ProductName
FROM Products
LEFT JOIN OrderDetails ON Products.ProductID = OrderDetails.ProductID
WHERE OrderDetails.OrderID IS NULL;

4. 查找所有有優惠券的訂單的訂單日期、客戶名稱、訂單總金額。

SELECT Orders.OrderDate,Customers.CustomerName,SUM(OrderDetails.UnitPrice * OrderDetails.Quantity * (1 - OrderDetails.Discount)) AS TotalAmount
FROM Orders
JOIN Customers ON Orders.CustomerID = Customers.CustomerID
JOIN OrderDetails ON Orders.OrderID = OrderDetails.OrderID
WHERE Orders.Coupon<>''
GROUP BY Orders.OrderID;

5. 查找所有有訂單的城市中，訂單總金額最高的城市名稱和訂單總金額。

SELECT Customers.City,SUM(OrderDetails.UnitPrice * OrderDetails.Quantity * (1 - OrderDetails.Discount)) AS TotalAmount
FROM Orders
JOIN Customers ON Orders.CustomerID = Customers.CustomerID
JOIN OrderDetails ON Orders.OrderID = OrderDetails.OrderID
GROUP BY Customers.City
ORDER BY TotalAmount DESC
LIMIT 1;

在實際開發中，多表操作是復雜數據管理的有效手段。以上試題只是冰山一角，希望能為你提供啟示。