sql - 将多个简单查询转换为单个查询？

Question

我是 SQL 的新手，所以必须像我 5 岁一样解释事情。我试图弄清楚有多少人执行了“单击了解更多”事件，然后继续执行该事件“设置试用状态”。我使用的是 Postgres，所以还有一个额外的 AND payload->>'status' = true 我为了简化它而省略了它。本质上，我需要将以下伪查询转换为功能性单一查询。

SELECT DISTINCT booking_id
FROM venue_events
WHERE name = 'clicked learn more'`;

SELECT count(*)
FROM venue_events
WHERE booking = booking_id AND name = 'set trial status' AND payload->>'status' = true;

我怎样才能将它变成一个本质上的单个 SQL 查询，第二个使用第一个中的 booking_ids

下面是表格中的数据。

Answer 1

如果没有看到表结构和示例数据，很难完全确定，但如果您想获得您在对另一个答案的评论中提到的所有计数，我认为这个查询就是您所需要的。

SELECT v1.booking_id AS booking_id,
       COUNT(v1.booking_id) AS Clicked_learn_more, 
       COUNT(v2.booking_id) AS Set_trial_status_true,
       COUNT(v3.booking_id) AS Completed_booking
FROM (SELECT DISTINCT booking_id 
      FROM venue_events 
      WHERE name='clicked learn more' AND payload->>'status' = true) v1
LEFT JOIN (SELECT DISTINCT booking_id 
           FROM venue_events 
           WHERE name='set trial status' AND payload->>'status' = true) v2
    ON v2.booking_id = v1.booking_id
LEFT JOIN (SELECT DISTINCT booking_id 
           FROM venue_events 
           WHERE name='completed booking' AND payload->>'status' = true) v3
    ON v3.booking_id = v1.booking_id
GROUP BY v1.booking_id