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题解 | #查找当前薪水详情以及部门编号dept_no#

select salaries.emp_no,salary,from_date,salaries.to_date,dept_no from dept_manager left join salaries using(emp_no) order by salaries.emp_no

Mysql

2022-05-19

1 281

题解 | #筛选限定昵称成就值活跃日期的用户#

#先筛选出uid，其应满足最近一次试卷或练习在2021年9月，在从第一个表找其他满足条件的字段 select uid,nick_name,achievement from user_info where uid in ( select uid from exam_record ...

Mysql

2022-05-14

0 313

题解 | #对过长的昵称截取处理#

select uid, if(char_length(nick_name)>13, concat(substring(nick_name,1,10),'...'), nick_name ) as nick_name from user_info where char_length...

Mysql

2022-05-10

0 376

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,t from ( select exam_id,duration,release_time,tim...

Mysql

2022-05-08

3 319

题解 | #满足条件的用户的试卷完成数和题目练习数#

select er.uid,count(distinct er.exam_id) as exam_cnt, count(distinct pr.submit_time) as question_cnt #计数提交时间，就避免了表连接时的重复性 from exam_record as er left ...

Mysql

2022-05-06

0 222