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题解 | 游戏平台新玩家消费与进阶行为分析

SELECT p.player_id, p.username, p.level AS current_level, CASE WHEN p.level >= 30 THEN '高阶玩家' ELSE '新秀玩家' END A...

2026-02-01

0 13

题解 | SaaS平台企业客户新功能采纳度分析

WITH first_usage AS ( SELECT team_id, DATE_FORMAT(MIN(usage_timestamp), '%Y-%m-%d') AS first_ever_usage_date FROM feature_usa...

2026-02-01

0 16

题解 | 智能家居设备高能耗异常监控分析

WITH device_usage AS ( -- ① 每台设备 2025年1月总用电量 SELECT t2.device_id, t2.device_name, t2.category, t2.location, ...

2026-02-01

0 14

题解 | 国庆期间每类视频点赞量和转发量

WITH result AS ( SELECT info.tag, DATE(log.start_time) AS dt, SUM(log.if_like) AS like_cnt, SUM(log.if_retweet)...

2026-01-29

0 12

题解 | 获取employees中的first_name

select first_name from employees order by right(first_name,2)

2026-01-27

0 12

题解 | 获取所有非manager员工当前的薪水情况

select de.dept_no, de.emp_no, s.salary FROM employees e LEFT JOIN dept_emp de ON e.emp_no = de.emp_no LEFT JOIN salaries s ON e.emp_no = s.emp_no LEFT...

2026-01-27

0 12

题解 | 试卷发布当天作答人数和平均分

SELECT ei.exam_id, count(distinct er.uid) AS uv, round(AVG(er.score),1) AS avg_score FROM exam_record er LEFT JOIN user_info ui ON er....

2026-01-24

0 15

题解 | 月总刷题数和日均刷题数

-- 2021 每月 + 全年（全年分母固定 31） SELECT stat_month, COUNT(*) AS month_q_cnt, ROUND( COUNT(*) / DAY( LAST_DAY( ...

2026-01-24

0 16

题解 | 查找山东大学或者性别为男生的信息

SELECT device_id, gender, age, gpa FROM user_profile WHERE university = '山东大学' UNION ALL SELECT device_id, gender, age, gpa FROM user_profile WHERE ...

2026-01-24

0 17

题解 | 分析客户逾期情况

select c.pay_ability, concat(round(count(l.overdue_days)/count(*)*100,1),'%') overdue_ratio from loan_tb l left join customer_tb c using(customer_id) ...

2026-01-23

0 15