Question

我需要什么：我想按菜类显示销售额

我有三个表来解决这个问题：

1.order(dish_id,dish_price,dish_quantity)
2.dish(dish_id,dish_name,dish_cat_id)
3.dish_category(dish_cat_id,dis_cat_name

我想要的结果是： 我想要显示报告，已售出的数量，菜品类别以及总价格，total_quantity

预期的结果： dish_cat_id，dish_cat_name，total_price，total_quantity_sold

我的尝试：

    SELECT  d.dish_name, 
            d.dish_id,
            SUM(o.price) as total_price,
            SUM(o.dish_quantity) as total_qauntity 
    FROM order as o , dish as d
    WHERE o.dish_id = d.dish_id
    GROUP BY o.dish_id

现在我可以通过菜肴明智地获得所有菜肴及其总价格，如何获得它们 dish_category 明智

正确的是，我不知道预计会针对此查询的选定结果触发另一个查询，以便明智地将它们变为dish_category

Answer 1

SELECT  c.dis_cat_name , c.dish_cat_id ,
        SUM(o.price) as total_price ,
        SUM(o.dish_quantity) as total_qauntity 

FROM order as o JOIN  dish as d

       ON (o.dish_id = d.dish_id)
       join dish_category c on (d.dish_cat_id=c.dish_cat_id)

GROUP BY d.dish_cat_id

Answer 2

SELECT dc.dis_cat_name, 
       SUM(o.price) as total_price, 
       SUM(o.dish_quantity) as total_quantity 
FROM order o 
    INNER JOIN dish d ON o.dish_id = d.dish_id   
    INNER JOIN  dish_category dc ON dc.dish_cat_id = d.dish_cat_id
 GROUP BY dc.dish_cat_id;

Answer 3

你必须加入所有3个表：

select d2.dish_cat_id, d2.dish_cat_name, 
       sum(o1.dish_price) total_price ,sum(o1.dish_quantity) total_quantity_sold
from dish d1 join dish_category d2 on (d1.dish_cat_id= d2.dish_cat_id)
             join order o1 on (d1.dish_id = o1.dish_id)
group by d2.dish_cat_id, d2.dish_cat_name

希望通过逐个功能从单个查询中获取三个表中的所有数据

3 个答案: