Question

我试图让购物车形成1张桌子，只有1个条件，这是下一个“购物车必须比任何具有相同id_user的订单更新”

SELECT pso.*
FROM lafrips_cart pso
WHERE pso.id_customer > 0 
AND pso.date_add > (SELECT MAX(pso2.date_add)
FROM lafrips_orders pso2
WHERE pso2.id_customer < pso.id_customer)

我只是比较两个字段（pso.date_add和ps2.date_add）都是具有相同结构的datetime

Answer 1

SELECT pso.*
FROM lafrips_cart pso
WHERE 
    pso.id_customer > 0 
    AND pso.date_add > (
        SELECT MAX(pso2.date_add)
        FROM lafrips_orders pso2
        WHERE pso2.id_customer = pso.id_customer
        )

Answer 2

你们都说@Siyual和@Sergio“＆gt;”是错误，实际上我觉得我像砖一样厚，我可能要睡几个小时

SELECT pso.*
FROM lafrips_cart pso
WHERE
pso.id_customer > 0 
AND pso.date_add > (
    SELECT MAX(pso2.date_add)
    FROM lafrips_orders pso2
    WHERE pso2.id_customer **=** pso.id_customer
    )

标有** =符号替换

这个SQL查询有什么问题？

2 个答案: