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题解 | #实习广场投递简历分析(一)#

参考答案 select job, sum(num) as 'cnt' from resume_info where date between '2025-01-01' and '2026-01-01' group by job order by cnt desc # between 1 an...

Mysql

2021-11-06

0 348

题解 | #牛客的课程订单分析(七)#

参考答案 select if(oi.client_id=0,'GroupBuy',c.name) as 'source' , count(oi.client_id) as cnt from order_info oi left join client c on oi.client_id = c....

Mysql

2021-11-06

0 375

题解 | #牛客的课程订单分析(六)#

参考答案 select oi.id,oi.is_group_buy,if(oi.is_group_buy='No',c.name,null) from order_info oi left join client c on oi.client_id = c.id where date >...

Mysql

2021-11-06

0 353

题解 | #牛客的课程订单分析(四)#

参考答案 select user_id, min(date) as first_buy_date, count(user_id) as cnt from order_info where date > '2025-10-15' and product_name in ('java','pyt...

Mysql

2021-11-06

0 300

题解 | #牛客的课程订单分析(二)#

参考答案 select user_id from order_info where date > '2025-10-15' and status = 'completed' and product_name in ('c++','java','python') group by user_i...

Mysql

2021-11-05

0 303

题解 | #考试分数(二)#

参考答案 select * from grade g1 where g1.score > ( select AVG(g2.score) from grade g2 where g1.job = g2.job)

Mysql

2021-11-05

0 243

题解 | #刷题通过的题目排名#

本题解析考察窗口函数dense_rank() 使用方法:dense_rank() over(order by number desc) 参考答案 select id , number, (DENSE_RANK() over (order by number desc)) as t_ran...

Mysql

2021-11-05

0 320

题解 | #获取有奖金的员工相关信息。#

本题解析本题考查case....when...then...end语法的应用和多表联合查询参考答案 select e.emp_no, e.first_name, e.last_name, eb.btype, s.salary, (case when eb.btype=1 then ...

Mysql

2021-11-05

0 252

题解 | #使用含有关键字exists查找未分配具体部门的员工的所有信息。#

本题解析考察exists的用法参考答案 select * from employees e where not exists (select emp_no from dept_emp de where e.emp_no = de.emp_no) 知识拓展 in的用法 select *...

Mysql

2021-11-05

0 334

题解 | #分页查询employees表，每5行一页，返回第2页的数据#

参考答案 # 方法一: select * from employees limit 5,5; # 方法二: select * from employees limit 5 offset 5;

Mysql

2021-11-05

0 252