题解 | #计算用户的平均次日留存率#
计算用户的平均次日留存率
https://www.nowcoder.com/practice/126083961ae0415fbde061d7ebbde453
SELECT count(d2.device_id)/count(d1.device_id) as avg_ret
FROM(
SELECT DISTINCT device_id,date
FROM question_practice_detail )AS d1
left join
(SELECT DISTINCT device_id,date
FROM question_practice_detail )AS d2
ON d1.device_id=d2.device_id AND d2.date=DATE_ADD(d1.date,interval 1 day)
- 查询结果d1 和d 2 两个表格
- left join
- date_add
- interval
