[打卡]王俊影 多表查询2

use company;

select * from employees;

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


SELECT employee_id,department_name
FROM departments,employees
WHERE employees.department_id=departments.department_id(+);


SELECT employee_id,department_name
from employees e
join departments d
on e.department_id = d.department_id;

SELECT employee_id,department_name
from employees e inner
join departments d
on e.department_id = d.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;