Question

以下查询仅对内部查询（post_engagement，网站购买）产生正确的结果，而所有其他数字均错误地成倍增加。有任何想法吗？谢谢。

两个表的架构：

收藏夹广告（id，campaign_id，campaign_name，目标，展示次数，支出）

操作（id，ads_id，action_type，值）

SELECT
  f.campaign_id,
  f.campaign_name,
  f.objective,
  SUM(f.impressions) AS Impressions,
  SUM(f.spend) AS Spend,
  SUM(a.post_engagement) AS "Post Engagement",
  SUM(a.website_purchases) AS "Website Purchases"
FROM
favorite_ads f
LEFT JOIN (
     SELECT
          ads_id,
          CASE WHEN action_type = 'post_engagement' THEN SUM(value) END AS 
post_engagement,
      CASE WHEN action_type = 'offsite_conversion.fb_pixel_purchase' THEN SUM(value) END AS website_purchases
 FROM Actions a
 GROUP BY ads_id, action_type
) a ON f.id = a.ads_id
WHERE date_trunc('month',f.date_start) = '2018-04-01 00:00:00' AND 
date_trunc('month',f.date_stop) = '2018-04-01 00:00:00' --only get campaigns 
that ran in April, 2018
GROUP BY f.campaign_id, campaign_name, objective
Order by campaign_id

Answer 1

在不知道实际的表结构，约束，依赖性和数据的情况下，很难说出问题出在哪里。

您的评论中已经有一些线索，您应该首先考虑。

例如，您编写的该子查询返回了正确的结果：

SELECT ads_id,
       CASE
         WHEN action_type = 'post_engagement'
         THEN SUM(value)
       END AS post_engagement,
       CASE
         WHEN action_type = 'offsite_conversion.fb_pixel_purchase'
         THEN SUM(value)
       END AS website_purchases
  FROM Actions a
 GROUP BY ads_id, action_type

这也能给出正确的结果吗？

SELECT ads_id,
       SUM(
         CASE
           WHEN action_type = 'post_engagement'
           THEN value
         END
       ) AS post_engagement,
       SUM(
         CASE
           WHEN action_type = 'offsite_conversion.fb_pixel_purchase'
           THEN value
         END
       ) AS website_purchases
  FROM Actions
 GROUP BY ads_id

如果是这样，请尝试用该子查询替换子查询。

如果您仍然遇到问题，那么我将调查您的加入条件是否正确（看起来似乎），对于一个广告系列（campaign_id），您可能会有多个具有相同{{1 }}，它将乘以子查询结果-具体取决于id中的主键（或唯一约束）。

连接两个表后立即查询结果一半

1 个答案: