mysql |具体要求

Question

我有mysql列：

[{"name":"Color","value":"Red (+5$)","price":"+5"}] // options column 

，并要求：

SELECT C.options, C.qty, P.PRICE 
FROM `cart` C 
LEFT JOIN `products` P ON C.productid = P.id 
WHERE C.userid = '3c9494e7ff22e2a7ac01a3e95fbbc0e4' 

但我需要这样的：

SELECT C.options, C.qty, (P.PRICE + (substract price +5 from options column))*C.qty 
FROM `cart` C 
LEFT JOIN `products` P ON C.productid = P.id 
WHERE C.userid = '3c9494e7ff22e2a7ac01a3e95fbbc0e4' 

是否有可能获得上述要求？ 谢谢。

Answer 1

我认为要汇总值

试试这个

SELECT C.options, C.qty, SUM(P.PRICE + c.options) * C.qty 
FROM `cart` C 
LEFT JOIN `products` P ON C.productid = P.id 
WHERE C.userid = '3c9494e7ff22e2a7ac01a3e95fbbc0e4' 
GROUP BY c.options,c.qty 

如果您需要将选项列转换，做这样的

SELECT C.options, C.qty, SUM(P.PRICE + CAST(c.options AS DECIMAL)) * C.qty 
FROM `cart` C 
LEFT JOIN `products` P ON C.productid = P.id 
WHERE C.userid = '3c9494e7ff22e2a7ac01a3e95fbbc0e4' 
GROUP BY c.options,c.qty