[打卡]多表查询。

SELECT employee_id,last_name,department_name,city
from employees,departments,locations
WHERE employees.department_id = departments.department_id
AND departments.location_id = locations.location_id;


SELECT * from job_grades;

SELECT e.last_name,e.salary,j.grade_level
from employees e,job_grades j
WHERE e.salary BETWEEN j.lowest_sal AND j.highest_sal;

SELECT e.last_name,e.salary,j.grade_level
from employees e,job_grades j
WHERE e.salary >=j.lowest_sal AND e.salary <= j.highest_sal;

SELECT * from employees;

SELECT emp.employee_id,emp.last_name,mgr.employee_id, mgr.last_name
FROM employees emp,employees mgr
WHERE emp.manager_id = mgr.employee_id;