说明: 例如:按照 department id 查询 employees 员工表 和 departments 部门表 的信息 方式一 通用型 :SELECT FROM WHERE SELECT e last name e department id d department name FROM employees e departments d where e department id d department id 方式二:SELECT FROM NATURAL JOIN 有局限性:会自动连接两个 <w1025508785> 上传 | 大小:358kb