#案例:查询员工的名字和对应上级的名字
SELECT
e.last_name,m.last_name
FROM
employees e
JOIN
employees m
ON
e.`manager_id`=m.`employee_id`
#案例:查询员工的名字和对应上级的名字
SELECT
e.last_name,m.last_name
FROM
employees e
JOIN
employees m
ON
e.`manager_id`=m.`employee_id`