mysql sql99语法 内连接非等值连接

#案例：查询员工的工资级别

SELECT    salary,grade_levelFROM    employees eJOIN    job_grades gON    e.`salary` BETWEEN g.`lowest_sal` AND g.`lowest_sal`;

#案例：查询每个工资级别的个数，并且按级别降序

SELECT    COUNT(*),grade_levelFROM    job_grades jJOIN    employees eON    e.`salary` BETWEEN j.`lowest_sal`AND j.`highest_sal`GROUP BY    grade_level DESC;