Question

我有以下SQL查询：

SELECT date_format(sfo.shipping_arrival_date,"%m.%Y") AS Month,
       date_format(sfo.shipping_arrival_date,"%v") AS Week,
       date_format(sfo.shipping_arrival_date,"%d.%m.%Y") AS Shipping Day,
       CASE
           WHEN sfo.coupon_code IS NOT NULL THEN sfo.coupon_code
           ELSE 'no Code'
       END as Coupon,
       sfo.coupon_rule_name,
       sfo.grand_total AS Endsumme,
       sfo.base_subtotal + sfo.shipping_incl_tax AS Sum_Incl_Shipping,
       sfo.discount_amount,
       count(sfo.entity_id) AS uses
FROM sales_flat_order AS sfo
WHERE sfo.status <> 'canceled'
GROUP BY Coupon
ORDER BY sfo.shipping_arrival_date DESC

在sfo.coupon_code中是值＆＃34; NULL＆＃34;现有的，但查询不会将它们列为＆＃34;没有代码＆＃34;在结果中。我想要一份分组的优惠券代码和相关值的列表。

有谁知道为什么我找不到价值＆＃34;没有代码＆＃34;在我的结果？

感谢。

Answer 1

我的预感是NULL的{{1}}值只有coupon_code，sfo.status = NULL的记录会从结果集中省略。

尝试使用以下查询：

SELECT date_format(sfo.shipping_arrival_date,"%m.%Y") AS Month,
       date_format(sfo.shipping_arrival_date,"%v") AS Week,
       date_format(sfo.shipping_arrival_date,"%d.%m.%Y") AS Shipping Day,
       CASE
           WHEN sfo.coupon_code IS NOT NULL THEN sfo.coupon_code
           ELSE 'no Code'
       END as Coupon,
       sfo.coupon_rule_name,
       sfo.grand_total AS Endsumme,
       sfo.base_subtotal + sfo.shipping_incl_tax AS Sum_Incl_Shipping,
       sfo.discount_amount,
       count(sfo.entity_id) AS uses
FROM sales_flat_order AS sfo
WHERE sfo.status <> 'canceled' OR sfo.status IS NULL
GROUP BY Coupon
ORDER BY sfo.shipping_arrival_date DESC

Answer 2

我使用COALESCE代替CASE ......

customerContracts

...因为COALESCE表达式是CASE表达式的语法快捷方式，因此更清晰简洁

MySQL - 按空值分组

2 个答案: