求职小张957

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题解 | #未完成率较高的50%用户近三个月答卷情况#

SELECT uid, start_month ,COUNT(start_month) AS total_cnt ,COUNT(submit_time) AS complete_cnt FROM ( SELECT uid, exam_id, level, su...

2024-09-27

0 82

题解 | #连续两次作答试卷的最大时间窗#

SELECT uid, MAX(day_window) AS days_window, ROUND(MAX(times)/MAX(day_total)*MAX(day_window), 2) AS avg_exam_cnt FROM ( SELECT...

2024-09-26

0 50

题解 | #第二快/慢用时之差大于试卷时长一半的试卷#

SELECT exam_id ,duration ,release_time FROM ( SELECT exam_id, duration, release_time, SUM(CASE WHEN ranking1 =...

2024-09-23

0 89

题解 | #每个6/7级用户活跃情况#

SELECT uid, IFNULL(act_month_total, 0), IFNULL(act_days_2021, 0), IFNULL(act_days_2021_exam, 0), IFNULL(act_days_2021_...

2024-09-22

0 75

题解 | #月均完成试卷数不小于3的用户爱作答的类别#

SELECT tag, COUNT(tag) AS tag_cnt FROM exam_record JOIN examination_info USING(exam_id) WHERE uid IN ( SELECT uid FROM exam_record ...

2024-09-21

0 74

题解 | #平均活跃天数和月活人数#

SELECT DATE_FORMAT(submit_time, "%Y%m") AS month, ROUND(COUNT(DISTINCT uid, DATE_FORMAT(submit_time, '%y%m%d'))/COUNT(DISTINCT uid),...

2024-09-19

0 97

题解 | #得分不小于平均分的最低分#

SELECT MIN(score) AS min_score_over_avg FROM exam_record JOIN examination_info USING(exam_id) WHERE tag = "SQL" AND score >= ( SE...

2024-09-19

0 95

题解 | #统计作答次数#

SELECT COUNT(start_time) AS total_pv, COUNT(submit_time) AS complete_pv, ( SELECT COUNT( DISTINCT exam_id) FROM exam_reco...

2024-09-19

0 70

题解 | #修改表#

ALTER TABLE user_info ADD COLUMN school VARCHAR(15) AFTER level; ALTER TABLE user_info CHANGE COLUMN job profession VARCHAR(10); ALTER TABLE user_info...

2024-09-17

0 71

题解 | #浙大不同难度题目的正确率#

SELECT difficult_level, SUM(IF(qpd.result = "right", 1,0 ))/COUNT(qpd.question_id) AS correct_rate FROM user_profile JOIN question...

2024-09-15

0 87