Question

我有3张表，deep_merge，Product(ID, Name, Price)和Category(ID, Name)。

我通过Product_Category在Product和Category之间建立了很多关系。但是，我想显示每个类别的最低/最高价格，这是我得到了多远：

Product_Category(ProductID, CategoryID)

我希望每个类别的最便宜和最昂贵的产品的价格按类别分组，如下所示：

SELECT 
(SELECT MIN(Product.Price) FROM Product) AS 'Lowest price', 
(SELECT MAX(Product.Price) FROM Product) AS 'Highest price', 
Category.Name AS CategoryName

FROM Product_Category 
JOIN Product ON Product_Category.ProductID = Product.ID 
JOIN Category ON Product_Category.CategoryID = Category.ID
GROUP BY Category.Name

Answer 1

不需要子查询：

SELECT 
    MIN(Product.Price) AS 'Lowest price', 
    MAX(Product.Price) AS 'Highest price', 
    Category.Name AS CategoryName
FROM Product_Category 
    JOIN Product ON Product_Category.ProductID = Product.ID 
    JOIN Category ON Product_Category.CategoryID = Category.ID
GROUP BY Category.Name

获得多对多的最高/最低价值

1 个答案: