[打卡]霍宝杰 多表查询

desc employees;
desc departments;
select e.employee_id,d.department_name
from employees,departments;


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

select * from employees;


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