[打卡]闫冬浩-多表查询

select employee_id,department_name
from employees,departments
where employees.department_id = departments.department_id;

select * from employees;

select employee_id,department_name
from employees inner join departments
on departments.department_id =employees.department_id;

select employee_id,department_name,city
from employees e join departments d on e.department_id = d.department_id
join locations l on d.location_id = l.location_id;

select employee_id,department_name
from employees e left OUTER join departments d
on e.department_id = d.department_id;

select employee_id,department_name
from employees e right OUTER join departments d
on e.department_id = d.department_id;