一个查询中的购物清单价格总和

Question

我有以下数据库结构：

[Table `lists`] 
one has many [Table `lists_positions`] 
  one has one [Table `products`] 
    many has many through [Table `products_prices_tables`] [Table `prices_tables`] 
      has many [Table `prices`]

是否有可能获得所有产品的总和＆＃39;数据库中所有现有清单中的价格？

我尝试过：

SELECT x.list_id AS id, x.modified_on AS modified_on, ROUND(SUM(x.sum_price), 2) AS cart_price
FROM (
    SELECT list_id, modified_on, AVG(y.price_weight) AS sum_price
    FROM (
        SELECT l.id AS list_id, l.modified_on AS modified_on, pr.price_weight AS price_weight
        FROM `lists_positions` lp
        INNER JOIN `lists` l ON l.id = lp.list_id
        INNER JOIN `products` p ON p.id = lp.product_id
        LEFT JOIN `products_prices_tables` ppt ON ppt.product_id = p.id 
        LEFT JOIN `prices_tables` pt ON pt.id = ppt.price_table_id 
        LEFT JOIN `prices` pr ON pr.price_table_id = pt.id
        GROUP BY l.id
    ) y
    GROUP BY y.list_id
) x
GROUP BY x.list_id

但它似乎不起作用。

提前致谢。

编辑：这似乎对我有用：

SELECT modified_on, ROUND(SUM(y.price_weight), 2) AS sum_price
FROM (
    SELECT DATE(l.modified_on) AS modified_on, 
    (AVG(pr.price_weight) * lp.amount) AS price_weight
    FROM `lists_positions` lp
    INNER JOIN `lists` l ON l.id = lp.list_id
    INNER JOIN `products` p ON p.id = lp.product_id
    INNER JOIN `users` u ON u.id = l.user_id
    INNER JOIN `products_prices_tables` ppt ON ppt.product_id = p.id 
    INNER JOIN `prices_tables` pt ON pt.id = ppt.price_table_id 
    INNER JOIN `prices` pr ON pr.price_table_id = pt.id
    WHERE (
    (:sexCriteria) AND (:rangeCriteria)
    ) GROUP BY lp.id
) y
GROUP BY y.modified_on