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题解 | #牛客直播各科目出勤率#

#主要的坑点在于：有人提前进入了直播间，而提前的时间并计算到在线时长中 SELECT course_id ,course_name ,ROUND(100*SUM(is_online)/COUNT(course_id),2) AS attend_rate FROM ( SELE...

2024-01-16

1 207

题解 | #牛客直播各科目同时在线人数#

SELECT t3.course_id ,course_name ,max_num FROM (SELECT course_id ,MAX(cnt) AS max_num FROM ( SELECT course_id ,SUM(live)OVER...

2024-01-16

0 181

题解 | #考试分数(四)#

SELECT DISTINCT job,IF(up_rk<=down_rk,up_rk,down_rk) AS START ,IF(up_rk<=down_rk,down_rk,up_rk) AS END FROM ( SELECT * ,DENSE_RAN...

2024-01-16

0 199

题解 | #牛客每个人最近的登录日期(五)#

SELECT t0.date ,ROUND(IFNULL(COUNT(t2.user_id)/COUNT(t1.user_id),0),3) AS p FROM (SELECT DATE FROM login GROUP BY DATE) AS t0 LEFT JOIN (SELECT ...

2024-01-16

0 172

题解 | #牛客每个人最近的登录日期(六)#

SELECT NAME,b.date,SUM(NUMBER) OVER(PARTITION BY NAME ORDER BY c.date) AS ps_num FROM user AS a LEFT JOIN login AS b ON a.id = b.user_id LEFT JOIN pa...

2024-01-16

1 158

题解 | #牛客每个人最近的登录日期(四)#

SELECT DATE ,SUM(CASE WHEN DATE=first_login THEN 1 ELSE 0 END) AS NEW FROM ( SELECT * ,MIN(DATE) OVER(PARTITION BY user_id...

2024-01-16

0 163

题解 | #牛客每个人最近的登录日期(三)#

SELECT ROUND(COUNT(id)/COUNT(a.user_id),3) AS p FROM (SELECT user_id,MIN(DATE) AS DATE FROM login GROUP BY user_id ) AS a LEFT JOIN login AS b ON a.us...

2024-01-16

1 175

题解 | #异常的邮件概率#

SELECT DATE ,ROUND(SUM(IF(TYPE = 'no_completed',1,0))/COUNT(id),3) AS p FROM email WHERE send_id IN (SELECT id FROM user WHERE is_blacklist =...

2024-01-16

1 181

题解 | #网易云音乐推荐(网易校招笔试真题)#

select music_name from (SELECT distinct music_name,music_id FROM (SELECT * FROM ( SELECT follower_id FROM follow WHERE user_id = 1 ) AS t1 LEFT JOIN m...

2024-01-16

1 180

题解 | #网易云音乐推荐(网易校招笔试真题)#

select music_name from (SELECT distinct music_name,music_id FROM (SELECT * FROM ( SELECT follower_id FROM follow WHERE user_id = 1 ) AS t1 LEFT JOIN m...

2024-01-16

1 165