尚硅谷]_宋红康_常用sql操作总结

例如：按照departmentid查询employees员工表和departments部门表的信息方式一通用型:SELECTFROMWHERESELECTelastnameedepartmentidddepartmentnameFROMemployeesedepartmentsdwhereedepartmentidddepartmentid方式二：SELECTFROMNATURALJOIN有局限性：会自动连接两个表中相同的列可能有多个:department