sql - SQL `order` .id 未知列中的变量范围

Question

在以下查询中，错误 Unknown column 'order.id' in 'on clause' 是由我在 INNER JOIN 中的 order.id 引用引发的。 id 列确实存在。

知道为什么它不能通过子查询访问吗？

SELECT
    SUM(price+shipping_price) AS total_sales,
    COUNT(id) AS total_orders,
    AVG(price+shipping_price) AS order_total_average,
    (SELECT
            SUM(quantity)
        FROM `order_product`
        WHERE `order`.id = order_product.order_id
    ) as total_units,
    SUM(price+shipping_price)/7 as daily_average,
    (SELECT
            SUM(order_product.price * order_return_product.quantity)
        FROM order_return_product
        INNER JOIN order_product ON (
            order_product.order_id = `order`.id AND
            order_product.product_id = order_return_product.product_id AND
            order_product.vehicle_id = order_return_product.vehicle_id
        )
        WHERE return_id IN (
            SELECT
                id
            FROM order_return
            WHERE status_id != 3 AND
            order_return.order_id = `order`.id
        )
    ) as total_returns
FROM `order`
WHERE created >= 1278388801 AND
created <= 1279079999 AND
fraud = 0 AND
type_id = 4

当我注释掉 INNER JOIN 中的 order.id 时，我没有收到任何错误

Answer 1

order.id 超出此查询的范围 - 您只处理子查询中的 order_return_product 和 order_product 表.