GB279824

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题解 | 刷题通过的题目排名

# select id,number, # dense_rank() over(order by number DESC) dr # from passing_number # order by # dr ASC,id ASC; select id,number, de...

2025-05-26

0 40

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 order by number ASC;

2025-05-26

0 47

题解 | 给出employees表中排名为奇数行的first_name

select e.first_name from employees e where ( select count(*) from employees e1 where e.first_name >= e1.first_name ) % 2 = 1; 1）为什么是>...

2025-05-26

0 34

题解 | 获取有奖金的员工相关信息。

select e.emp_no,first_name,last_name,btype,salary, (case btype when 1 then salary*0.1 when 2 then salary*0.2 else salary * 0.3 end) as...

2025-05-26

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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。

select * from employees e where not exists( select emp_no from dept_emp d where e.emp_no = d.emp_no );

2025-05-25

0 35

题解 | 分页查询employees表，每5行一页，返回第2页的数据

# select * # from employees # limit (2-1)*5,5; select * from employees limit 5 offset 5;

2025-05-25

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题解 | 平均工资

select avg(salary) as avg_salary from salaries where to_date = '9999-01-01' and salary not in (select max(salary) from salaries where to_date = '9999-...

2025-05-25

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题解 | 按照dept_no进行汇总

select dept_no, group_concat(emp_no) as employees from dept_emp group by dept_no; GROUP_CONCAT([DISTINCT] column_name [ORDER BY column_name [A...

2025-05-25

0 35

题解 | 获取employees中的first_name

select first_name from employees order by substring(first_name,-2,2) ASC;

2025-05-25

0 35

题解 | 查找字符串中逗号出现的次数

select id,length(string)-length(replace(string,',','')) from strings; 用总的字符长度减去删除掉','符号的字符总长度得到的就是其中','符号的数量。

2025-05-25

0 34