mysql - SQL 查询显示昨天创建的所有用户，有多少发送的邀请？

Question

我有以下查询:

SELECT floor(datediff(u.created_at, curdate()) / 1) AS days_ago,
       count(DISTINCT u.id) AS "New Users in Cohort", 
       count(DISTINCT i.user_id) AS "Uniq Users who invited Cohort",
count(DISTINCT u.id) / count(DISTINCT i.user_id) AS "% who invite"
FROM users u 
LEFT JOIN invitations i
     ON u.id = i.user_id
WHERE u.onboarding_started_at IS NOT NULL
GROUP BY days_ago;

我正在尝试让查询返回以下内容:

+----------+-----------+--------------------------+--------------+
| days_ago | New Users | Unique Users who Invited | % who invite |
+----------+-----------+--------------------------+--------------+
|        1 |        20 |                       10 | 50%          |
+----------+-----------+--------------------------+--------------+

新用户将是其中 u.created_at 是查询使用的日期

我做错了什么？谢谢!

Answer 1

你说的还不够让我判断是否DISTINCT是需要的。

LEFT似乎没有必要。

“昨天”是 `... >= CURDATE() - 间隔 1 天并且 ... < CURDATE()

SELECT count(DISTINCT u.id) AS "New Users in Cohort", 
       count(DISTINCT i.user_id) AS "Uniq Users who invited Cohort",
       count(DISTINCT u.id) / count(DISTINCT i.user_id) AS "% who invite"
FROM users u 
JOIN invitations i
     ON u.id = i.user_id
WHERE u.onboarding_started_at IS NOT NULL
  AND u.created_at >= CURDATE() - INTERVAL 1 DAY
  AND u.created_at  < CURDATE()

如果您想要多天的计数，那么我会使用 DATE(u.created_at)作为DATE显示和 GROUPing BY 的值。 (除非你真的想要“days_ago”。)