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题解

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题解 | #批量插入数据，不使用replace操作# 来自专栏

insert ignore into actor VALUES( '3', 'WD','GUINESS','206-02-15 12:34:33' ) 《SQL必知必会》里面没有，边练边学吧

Mysql

2021-09-27

0 304

题解 | #批量插入数据# 来自专栏

插入一条数据,可以写列名也可以不写列名 insert into actor(actor_id,first_name,last_name,last_update) VALUES (2,'NICK','WAHLBERG','2006-02-15 12:34:33'); insert into acto...

Mysql

2021-09-26

0 373

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# 来自专栏

select title, description from film where film_id in (select film_id from film_category where category_id in (select category_id from category where n...

Mysql

2021-09-26

0 479

题解 | #查找描述信息中包含robot的电影对应的分类名称以及电影数目，而且还需要该分类对应电影数量>=5部# 来自专栏

select name, r_count from (select category_id,count(f.film_id) as r_count from film as f inner join film_category as fc on f.film_id = fc.film_id wh...

Mysql

2021-09-26

0 515

题解 | #汇总各个部门当前员工的title类型的分配数目# 来自专栏

select d.dept_no, dept_name, title, count from departments as d right outer join (select dept_no, title, count(title) as count from titles as t left o...

Mysql

2021-09-26

1 386

题解 | #获取员工其当前的薪水比其manager当前薪水还高的相关信息# 来自专栏

评价“华科平凡不？”同学的解题思路 # 来自“华科平凡不？” select d.emp_no, de.emp_no as manager_no, s.salary as emp_salary, se.salary as manager_salary from dept_emp as d, de...

Mysql

2021-09-25

0 352

题解 | #获取员工其当前的薪水比其manager当前薪水还高的相关信息# 来自专栏

select e_emp_no, m_emp_no, e_salary, m_salary from (select e_emp_no, salary as e_salary, dept_no from salaries as s, (select e.emp_no as e_emp_no,...

Mysql

2021-09-25

0 423

题解 | #获取所有非manager员工当前的薪水情况# 来自专栏

select dept_emp.dept_no, employees.emp_no, salary from employees inner join salaries on employees.emp_no = salaries.emp_no inner join dept_emp on emp...

Mysql

2021-09-25

1 466

题解 | #对所有员工的薪水按照salary降序进行1-N的排名# 来自专栏

select emp_no, salary, DENSE_RANK() over(order by salary desc) as t_rank from salaries ORDER BY t_rank, emp_no; 这道题最难的地方在于，之前没有学过排名函数。下面介绍几种排名方法。 --...

Mysql

2021-09-25

0 353

题解 | #统计各个部门的工资记录数# 来自专栏

select dept_no, count(salary) as sum from salaries left outer join dept_emp on salaries.emp_no = dept_emp.emp_no group by dept_no; select ds.dept_no,...

Mysql

2021-09-25

0 497