SQL-请统计每个访问渠道7天前（D-7）的新用户的3日留存和7日留存率。

您好，

SELECT plat, COUNT(DISTINCT user_id) FROM person_visit
WHERE MIN(DATE_FORMAT(visit_date, '%Y%m%d')) = (CURDATE()-INTERVAL 7 DAY)
GROUP BY plat;

SELECT plat, COUNT(DISTINCT user_id) FROM person_visit
WHERE DATE_FORMAT(visit_date,  '%Y%m%d') = (CURDATE()-INTERVAL 4 DAY) AND
user_id IN (SELECT user_id FROM person_visit
WHERE MIN(DATE_FORMAT(visit_date,  '%Y%m%d')) = (CURDATE()-INTERVAL 7 DAY))
GROUP BY plat;

SELECT plat, COUNT(DISTINCT user_id) FROM person_visit
WHERE DATE_FORMAT(visit_date, '%Y%m%d') = CURDATE() AND
user_id IN (SELECT user_id FROM person_visit
WHERE MIN(DATE_FORMAT(visit_date,  '%Y%m%d')) = (CURDATE()-INTERVAL 7 DAY))
GROUP BY plat;