mysql 分组并加入

Question

我想按“食物”和“饮料”等菜单类型从 bar_purchase_request table 组中获取总计。我试过以下查询：

SELECT  DISTINCT(b.name),
        0 as food_total,
        0 as drink_total,
        sum(ph.total) as total,
        sum(ph.gratuity) as gratuity
    from  branches b
    LEFT JOIN  drink_requests dr  ON b.id = dr.branch_id
    JOIN  drink_food df  ON df.id = dr.drink_id
    JOIN  bar_purchase_history ph  ON ph.request_id = dr.id
    GROUP BY  dr.branch_id;

你可以检查我的 table 结构如下：

请求table结构：

菜单项table结构：

我想要这样的结果：

任何人都可以提供帮助。

Answer 1

我创建了查询并为我工作：

SELECT b.name as branch_name,SUM(CASE WHEN df.type = 'drink' THEN bph.price ELSE 0 END) as  totalDrink,SUM(CASE WHEN df.type = 'food' THEN bph.total ELSE 0 END) as totalFood,SUM(bph.gratuity) as gratuity, sum(bph.total) as total FROM bar_purchase_history bph JOIN drink_food df ON bph.item_id = df.id JOIN drink_requests dr ON bph.request_id = dr.id JOIN branches b ON dr.branch_id = b.id where dr.branch_id = 1 GROUP BY dr.branch_id;

mysql 分组并加入

mysql groupby and join

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