SQL 将单独的查询作为原始查询中的一列加入

Posted 2023-05-08

【中文标题】SQL 将单独的查询作为原始查询中的一列加入

【英文标题】：SQL joining a separate query as a column in original query

【发布时间】：2021-02-12 05:05:48

【问题描述】：

我正在努力加入以下两个查询。

我的主要查询是下面的第一个查询，我想要实现的是查询 2 的 opt in rate 列的输出作为我原始查询中的新列。

SELECT CAST("public"."event_event"."date_created" AS date) AS "date_created", "marketing_message__via__messag"."name" AS "name", count(*) AS "count"

FROM "public"."event_event"

LEFT JOIN "public"."marketing_message" "marketing_message__via__messag" ON "public"."event_event"."message_id" = "marketing_message__via__messag"."id" LEFT JOIN "public"."marketing_campaign" "marketing_campaign__via__campa" ON "public"."event_event"."campaign_id" = "marketing_campaign__via__campa"."id"

WHERE (date_trunc('month', CAST("public"."event_event"."date_created" AS timestamp)) = date_trunc('month', CAST(now() AS timestamp))
   AND "marketing_message__via__messag"."name" IS NOT NULL AND ("marketing_message__via__messag"."name" <> ''
    OR "marketing_message__via__messag"."name" IS NULL) AND "public"."event_event"."stage" = 'Lead' AND ("marketing_campaign__via__campa"."name" = 'a' 
OR "marketing_campaign__via__campa"."name" = 'b'
OR "marketing_campaign__via__campa"."name" = 'c' 
OR "marketing_campaign__via__campa"."name" = 'c1' OR "marketing_campaign__via__campa"."name" = 'd' 
OR "marketing_campaign__via__campa"."name" = 'e'))

GROUP BY CAST("public"."event_event"."date_created" AS date), "marketing_message__via__messag"."name"

ORDER BY CAST("public"."event_event"."date_created" AS date) ASC, "marketing_message__via__messag"."name" ASC

我想将“选择加入率”的以下查询输出作为新列添加到上面的查询中。

查询 2

SELECT marketing_message.message_text,
   
    cast(sum((event_event.status='Opt-in')::int) as decimal) / nullif(sum((event_event.status='Sent')::int), 0)* 100 as "Opt-in Rate (Sent)"
    
FROM event_event
JOIN marketing_campaign ON event_event.campaign_id = marketing_campaign.id
JOIN marketing_message ON event_event.message_id = marketing_message.id
WHERE True [[AND campaign_name]] [[AND date_created]]
GROUP BY marketing_message.message_text

【参考方案1】：

简短的回答是你不能。

您的第一个查询以日期和名称为关键字（GROUP BY 子句），您的第二个查询以 message_text 为关键字。由于两个数据集之间没有关系，因此无法在单个查询中加入/组合它们。

您需要在两个数据集之间找到一个公共字段（或多个字段）并加入它们 - 但这不会给出与您目前相同的结果，因为您的查询需要完全重组。