Question

我尝试在SUM（）函数中使用嵌套的CASE WHEN语法，但是自3天以来什么都没作用

当我检索所有求和和嵌套条件时，代码会很好工作

我解释：

对照表：每个客户都有一份合同，其中有两个值：Prix_TTC（商品价格），Qac_cont（客户每月必须消耗的商品数量）
表格命令：每个带有数量（Quantite_cmd）的客户订单商品

所以我想做的是让每个客户在实际月份中损失所有财务损失，并将所有这些金额相加

SELECT 
    SUM(pertes) AS pertes_reelles
FROM
    (SELECT 
        c.ID_clt,
            SUM(CASE
                WHEN
                    ((co.Qac_cont - SUM(CASE
                        WHEN Quantite_cmd IS NULL THEN 0
                        ELSE Quantite_cmd
                    END)) * - 1) < 0
                THEN
                    ((co.Qac_cont - SUM(CASE
                        WHEN Quantite_cmd IS NULL THEN 0
                        ELSE Quantite_cmd
                    END)) * - 1)
                ELSE 0
            END) * co.Prix_TTC AS pertes
    FROM
        clients c
    LEFT JOIN contrat co ON co.clt_ID = c.ID_clt
    LEFT JOIN commande cmd ON cmd.clt_ID = c.ID_clt
        AND MONTH(DATE(cmd.date_livr_cmd)) = MONTH(DATE('2019-08-30 09:23:23'))
    WHERE
        c.Etat_clt <> 'D'
    GROUP BY c.ID_clt) AS liste

Answer 1

就像@BobJarvis说的那样，问题出在嵌套的SUM上，所以我分解了嵌套的处理过程，谢谢！新的请求：

SELECT SUM(CASE
                WHEN
                    perte < 0
                THEN
                    perte * - 1
                ELSE 0
            END) AS pertes_reelles
FROM
    (SELECT 
        c.ID_clt, co.Prix_TTC, ((co.Qac_cont - SUM(CASE
                        WHEN Quantite_cmd IS NULL THEN 0
                        ELSE Quantite_cmd
                    END)) * - 1) as ecart, co.Prix_TTC * ((co.Qac_cont - SUM(CASE
                        WHEN Quantite_cmd IS NULL THEN 0
                        ELSE Quantite_cmd
                    END)) * - 1) as perte
    FROM
        clients c
    LEFT JOIN contrat co ON co.clt_ID = c.ID_clt
    LEFT JOIN commande cmd ON cmd.clt_ID = c.ID_clt
        AND MONTH(DATE(cmd.date_livr_cmd)) = MONTH(DATE('".$today."'))
    WHERE
        c.Etat_clt <> 'D'
    GROUP BY c.ID_clt) AS liste

请如何解决“组功能的无效使用”

1 个答案: