李彩莲 多表查询

SELECT e.employee_id,d.department_name FROM employees e,departments d WHERE e.department_id = d.department_id; 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 JOIN departments d ON e.department_id = d.department_id; SELECT e.employee_id,d.department_name FROM employees e,departments d WHERE 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 left join departments d on e.department_id = d.department_id; select employee_id,department_name from employees e right join departments d on e.department_id = d.department_id;