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全部文章（共10篇）

题解 | 短视频直播间晚上11-12点之间各直播间的在线人数

select room_id ,room_name ,count(distinct user_id) as user_count from user_view_tb left join room_info_tb using(room_id) where in_time between '23:0...

2025-12-04

0 32

题解 | 查询成绩

select count(*) from Student where sId in ( select sId from SC left join Course using(cId ) where cname in( '语文','数学','英语'...

2025-12-03

0 23

题解 | 请写出计算粉丝ctr的sql语句

select sum(read_num)/sum(show_num) as fans_ctr from c left join b on c.content_id = b.content_id left join a using(author_id) where c.fans_id = a.f...

2025-12-03

0 29

题解 | 网易云音乐推荐(网易校招笔试真题)

select music_name from music m join (select distinct music_id from music_likes where user_id in ( select follower_id from follow where user_id = 1 ...

2025-12-02

0 37

题解 | 查询单日多次下订单的用户信息？

select date(order_time) as order_date ,user_id ,count(order_id) as order_nums ,vip from uservip_tb join order_tb using(user_id) group by 1,2 having ...

2025-12-02

0 18

题解 | 更新用户积分信息？

select user_id ,(sum(order_price) + point) as point from uservip_tb join ( select user_id ,order_price from order_tb where order_p...

2025-12-02

0 15

题解 | 返回顾客名称和相关订单号以及每个订单的总价

select cust_name ,order_num ,( select sum(quantity*item_price) from OrderItems o where o.order_num = ord.order_num group by ord...

2025-12-01

0 19

题解 | 返回购买 prod_id 为 BR01 的产品的所有顾客的电子邮件（一）

select cust_email from Customers where cust_id in( select cust_id from Orders where order_num in( select order_num ...

2025-11-29

0 17

题解 | 浙大不同难度题目的正确率

select difficult_level ,count(case when result='right' then 1 end)/count(device_id) as correct_rate from question_practice_detail left join user_prof...

2025-11-25

0 26

题解 | 统计复旦用户8月练题情况

select device_id ,university ,count(question_id) as question_cnt ,count(case when result='right' then 1 end) as right_question_cnt from question_pract...

2025-11-25

0 24