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题解 | #查找排除当前最大、最小salary之后的员工的平均工资avg_salary#

select avg(salary) as avg_salaryfrom salarieswhere to_date = '9999-01-01'and salary not in (select min(salary) from salaries where t...

2021-08-25

1 481

题解 | #对first_name创建唯一索引uniq_idx_firstname#

drop table if exists actor;CREATE TABLE actor ( actor_id smallint(5) NOT NULL PRIMARY KEY, first_name varchar(45) NOT NULL, last_name varch...

2021-08-23

0 348

题解 | #创建一个actor_name表#

drop table if exists actor_name;create table actor_name( first_name varchar(45) not null comment'名字', last_name varchar(45) not null comment'姓氏'...

2021-08-23

0 314

题解 | #批量插入数据，不使用replace操作#

drop table if exists actor;CREATE TABLE actor ( actor_id smallint(5) NOT NULL PRIMARY KEY, first_name varchar(45) NOT NULL, last_name varcha...

2021-08-23

0 0

题解 | #创建一个actor表，包含如下列信息#

CREATE TABLE actor ( actor_id smallint(5) NOT NULL PRIMARY KEY, first_name varchar(45) NOT NULL, last_name varchar(45) NOT NULL, last_upda...

2021-08-22

0 483

题解 | #使用子查询的方式找出属于Action分类的所有电影对应的title,description#

select f.title,f.descriptionfrom film f join (select c.name,fc.film_id from category c left join film_category fc on...

2021-08-22

0 311

题解 | #统计各个部门的工资记录数#

select d.dept_no,d.dept_name,count(s.salary) as sumfrom dept_emp deleft join departments d on de.dept_no = d.dept_noleft join salaries s on de.emp_no=...

2021-08-21

0 271

题解 | #查找所有员工的last_name和first_name以及对应的dept_name#

select e.last_name,e.first_name,d.dept_namefrom employees eleft join dept_emp de on e.emp_no = de.emp_noleft join departments d on de.dept_no = d.dept...

2021-08-21

0 368

题解 | #获取所有员工当前的manager#

select de.emp_no,dm.emp_no as managerfrom dept_emp de inner join dept_manager dmon de.dept_no = dm.dept_nowhere de.emp_no != dm.emp_no;

2021-08-21

1 297

题解 | #牛客的课程订单分析(一)#

select *from order_infowhere status = 'completed'and product_name in ('C++','Java','Python')and date >= '2025-10-15'order by id;

2021-08-18

1 448