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题解 | #找到每个人的任务#

select p.id,p.name,t.content from person as p left join task as t on p.id = t.person_id order by p.id asc select p.id,p.name,t.content from person p l...

Mysql

2021-12-16

0 235

题解 | #出现三次以上相同积分的情况#

select number from grade group by number having count(number) >=3 SELECT number FROM grade GROUP BY number HAVING COUNT(number) >=3;

Mysql

2021-12-15

0 253

题解 | #将所有to_date为9999-01-01的全部更新为NULL#

update titles_test set to_date = null ,from_date = '2001-01-01' where to_date = '9999-01-01' update titles_test set to_date = null , from_date = '2001...

Mysql

2021-12-15

0 211

题解 | #删除emp_no重复的记录，只保留最小的id对应的记录。#

delete from titles_test where id not in (select * from (select min(id) from titles_test group by emp_no) as a) delete from titles_test where id not in...

Mysql

2021-12-15

0 303

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 emp_no,salary from salaries where salary = (select distinct(salary) from salaries order by salary desc limit 1,1) order by emp_no SELECT emp_no...

Mysql

2021-12-15

0 206

题解 | #查找薪水记录超过15次的员工号emp_no以及其对应的记录次数t#

select emp_no,count(salary) t from salaries group by emp_no having t>15; select emp_no,count(salary) t from salaries group by emp_no having t>15...

Mysql

2021-12-15

1 237

题解 | #Where in 和Not in#

import java.util.*; public class Balls { public int calcDistance(int A, int B, int C, int D) { return ((A+B+C+D)<<2) -(A+B+C+D); } }

Mysql

2021-12-14

0 379

题解 | #Where in 和Not in#

import java.io.BufferedReader; import java.io.InputStreamReader; import java.io.IOException; public class Main{ public static void main(String[] args)...

Mysql

2021-12-14

1 447

题解 | #Where in 和Not in#

SELECT tag,difficulty,ROUND((SUM(score)-max(score)-MIN(score))/(COUNT(score)-2),1) AS clip_avg_socre FROM exam_record as er join examination_info AS e...

Mysql

2021-12-14

0 292

题解 | #Where in 和Not in#

alter table examination_info drop index uniq_idx_exam_id; alter table examination_info drop index full_idx_tag; alter table examination_info drop inde...

Mysql

2021-12-14

0 360