猜201812181944403

分类

题解(3)

/ 注册

全部文章（共8篇）

题解 | 查询连续登陆的用户

select t3.user_id from register_tb t3 join (select user_id, 连续登录分组, count(*) 连续登录天数 from ( select user_id, date_sub(date(log_time),interval ...

2025-06-29

0 23

题解 | 浙大不同难度题目的正确率

with zd as ( select distinct(device_id) device_id from user_profile where university = '浙江大学' ), qu_detail as ( select question_practi...

2025-06-28

0 25

题解 | 统计复旦用户8月练题情况

with user as ( select distinct(device_id) d_id, university from user_profile where university='复旦大学' ), que_list as ( select device_id, co...

2025-06-28

0 19

题解 | 统计每个用户的平均刷题数

select up.university, qd.difficult_level, round(count(upd.id)/count(distinct(up.id)),4) avg_answer_cnt from user_profile up join question_practic...

2025-06-24

0 27

题解 | 统计每个学校各难度的用户平均刷题数

select a.university, c.difficult_level, round(count(b.id)/count(distinct(a.device_id)),4) avg_answer_cnt from user_profile a join questio...

2025-06-24

0 35

题解 | #统计每个用户的平均刷题数#

select a.university, c.difficult_level, count(b.question_id) / count(distinct(a.device_id)) avg_answer_cnt from question_practice_detail b join user_p...

Mysql

2021-11-13

0 356

题解 | #获取员工其当前的薪水比其manager当前薪水还高的相关信息#

SELECT f.emp_no, e.manager_no, f.salary, e.salary from (select -- 拉一张全员的薪资清单 b.emp_no, b.dept_n...

Mysql

2021-09-17

0 379

题解 | #获取当前薪水第二多的员工的emp_no以及其对应的薪水salary#

SELECT e.dept_no,d.emp_no,salary from salaries d inner join (#拉一张非管理员的员工清单 SELECT a.emp_no,b.dept_no from employees a LEFT join dept...

Mysql

2021-09-17

0 358