我可以在左外连接与普通表中使用SQL视图吗？

Question

这是我的看法

CREATE OR REPLACE VIEW w AS SELECT
orp1.order_product_id,
orp1.order_id,
pov1.weight,
sum(orp1.quantity) AS 'quantity'
FROM
`order_product` orp1,
`order_option` oro1,
`product_option_value` pov1
WHERE
pov1.option_id = 6 AND oro1.product_option_value_id = pov1.product_option_value_id AND orp1.order_product_id = oro1.order_product_id
GROUP BY
orp1.order_product_id,
orp1.order_id,
pov1.weight;

这是查询部分

FROM 
    `order_product` orp6,
    `product` p,
    `product_description` pd,
    `product_to_category` p2c
LEFT OUTER JOIN w ON orp6.order_id = w.order_id AND orp6.order_product_id = w.order_product_id

但是显示的错误是：

orp6.order_id 是未知列

Answer 1

请勿在FROM子句中使用逗号。 始终使用正确，明确， 标准的 JOIN语法。 在这

CREATE OR REPLACE VIEW w AS
    SELECT orp1.order_product_id, orp1.order_id, pov1.weight,
            sum(orp1.quantity) AS 'quantity'
    FROM `order_product` orp1 JOIN
         `order_option` oro1
         ON orp1.order_product_id = oro1.order_product_id JOIN
         `product_option_value` pov1
         ON oro1.product_option_value_id = pov1.product_option_value_id
    WHERE pov1.option_id = 6 
    GROUP BY orp1.order_product_id, orp1.order_id, pov1.weight;

然后，可以在FROM子句中添加其他JOIN ，例如要添加的JOIN 。