[打卡]谷加伟 多表查询二

SELECT e.last_name,d.department_id
FROM employees e,departments d
WHERE d.department_id=e.department_id;

SELECT employee_id,department_name
FROM employees e INNER JOIN departments d
ON e.department_id = d.department_id;

SELECT e.employee_id,d.department_name,l.city
FROM employees e INNER JOIN departments d
ON e.department_id = d.department_id
INNER 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;