MySQL的SUM（）子查詢（

Question

首先在這裏我想要做到：

獲取的etp_product.price和option_price的總和。

SELECT 
    etp_product.product_id, 
    etp_product.price, 
    (SELECT MIN(price) AS FIELD_2 FROM etp_product_option_value pov WHERE pov.product_id = etp_product.product_id) AS option_price 
FROM 
    etp_product 
GROUP BY 
    etp_product.product_id, 
    etp_product.price 

我已經試過這樣：

SELECT 
    etp_product.product_id, 
    etp_product.price, 
    (SELECT MIN(price) AS FIELD_2 FROM etp_product_option_value pov WHERE pov.product_id = etp_product.product_id) AS option_price, 
SUM(etp_product.price + option_price) AS Total 
FROM 
    etp_product 
GROUP BY 
    etp_product.product_id, 
    etp_product.price 

但得到這個錯誤：

Unknown column 'option_price' in 'field list'

任何想法如何它可以做？

Answer 1

SELECT 
etp_product.product_id, 
    etp_product.price, 
    (SELECT MIN(price) AS FIELD_2 FROM etp_product_option_value pov WHERE pov.product_id = etp_product.product_id) AS option_price, 
etp_product.price + (SELECT MIN(price) AS FIELD_3 FROM etp_product_option_value pov WHERE pov.product_id = etp_product.product_id) AS Total 
FROM 
    etp_product 
GROUP BY 
    etp_product.product_id, 
    etp_product.price 

Answer 2

SELECT 
    p.product_id, 
    p.price, 
    IFNULL(MIN(pv.price), 0) as option_price, 
    (p.price + IFNULL(MIN(pv.price), 0)) as total 
FROM etp_product p 
JOIN etp_product_option_value pv ON WHERE pv.product_id = p.product_id 
GROUP BY 
    p.product_id, 
    p.price