错题丨计算平均活跃天数和月活跃天数

平均活跃天数和月活人数

https://www.nowcoder.com/practice/9e2fb674b58b4f60ac765b7a37dde1b9?tpId=240&tqId=2183005&ru=/exam/oj&qru=/ta/sql-advanced/question-ranking&sourceUrl=%2Fexam%2Foj%3Ftab%3DSQL%25E7%25AF%2587%26topicId%3D240

除数和被除数直接用count计数,不要期待select出完整的结果来算,这样就复杂化了
看看

除法也可以尽量用round包起来做

SELECT DATE_FORMAT(submit_time,'%Y%m')MONTH,
ROUND(COUNT(DISTINCT uid,DATE_FORMAT(submit_time,'%Y%m%d'))/COUNT(DISTINCT uid),2)avg_active_days,
COUNT(DISTINCT uid)mau
from exam_record
WHERE year(submit_time)=2021
GROUP BY MONTH
全部评论

相关推荐

点赞 收藏 评论
分享
牛客网
牛客企业服务