题目描述
查找当前薪水(to_date='9999-01-01')排名第二多的员工编号emp_no、薪水salary、last_name以及first_name,不准使用order by
CREATE TABLE `employees` (
`emp_no` int(11) NOT NULL,
`birth_date` date NOT NULL,
`first_name` varchar(14) NOT NULL,
`last_name` varchar(16) NOT NULL,
`gender` char(1) NOT NULL,
`hire_date` date NOT NULL,
PRIMARY KEY (`emp_no`));
CREATE TABLE `salaries` (
`emp_no` int(11) NOT NULL,
`salary` int(11) NOT NULL,
`from_date` date NOT NULL,
`to_date` date NOT NULL,
PRIMARY KEY (`emp_no`,`from_date`));
输出描述
emp_no | salary | last_name | first_name |
---|---|---|---|
10009 | 94409 | Peac | Sumant |
试题详解
将employees表与salaries表内连接,在WEHRE语句中取出薪水最多的记录,再取最大即可在未使用order by的条件下获取到薪水第二多的员工的信息。代码如下:
SELECT e.emp_no,MAX(s.salary) AS salary,e.last_name,e.first_name
FROM employees AS e INNER JOIN salaries AS s
ON e.emp_no = s.emp_no
WHERE s.salary < (select max(salary) from salaries)
AND s.to_date = '9999-01-01';