牛客52838656号

分类

/ 注册

全部文章（共26篇）

题解 | #求解立方根#

import java.util.Scanner; // 注意类名必须为 Main, 不要有任何 package xxx 信息 public class Main { public static void main(String[] args) { Scanner in =...

2023-08-25

0 310

题解 | #求最小公倍数#

import java.util.Scanner; // 注意类名必须为 Main, 不要有任何 package xxx 信息 public class Main { public static void main(String[] args) { Scanner in =...

2023-08-25

0 364

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),2) avg_active_days...

2023-08-16

0 305

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 left join examination_info using (exam_id) where tag='SQL' and score >...

2023-08-15

0 329

题解 | #统计作答次数#

select count(start_time) total_pv, count(score) complete_pv, count(distinct exam_id and score is not null) complete_exam_cnt from exam_record

2023-08-15

0 259

题解 | #创建索引#

create index idx_duration on examination_info(duration); create unique index uniq_idx_exam_id on examination_info(exam_id); create fulltext index full...

2023-08-15

0 408

题解 | #删除记录（二）#

delete from exam_record where submit_time is null or timestampdiff(minute,start_time,submit_time)<5 order by start_time limit 3

2023-08-15

0 328

题解 | #更新记录（二）#

update exam_record set submit_time='2099-01-01 00:00:00',score=0 where date(start_time)<'2021-09-01' and submit_time is null

2023-08-15

0 322

题解 | #插入记录（一）#

insert into exam_record values (null,1001,9001,'2021-09-01 22:11:12','2021-09-01 23:01:12',90), (null,1002,9002,'2021-09-04 07:01:02',null,null)

2023-08-15

1 441

题解 | #将两个 SELECT 语句结合起来（一）#

select prod_id,quantity from OrderItems where prod_id like 'BNBG%' union select prod_id,quantity from OrderItems where quantity=100 order by prod_id a...

2023-08-15

0 379