#案例：查询员工的工资和工资级别 SELECT salary,grade_level FROM employees AS e,job_grades AS j WHERE salary BETWEEN j.`lowest_sal` AND j.`highest_sal` #e表的salary字段会和j表的每行字段挨个比较来源：51CTO作者：wx5d21d5e6e5ab1链接：https://blog.51cto.com/14437184/2437282 标签 mysql sal
