题目描述
找出所有员工当前(to_date=‘9999-01-01’)具体的薪水salary情况,对于相同的薪水只显示一次,并按照逆序显示
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`));
分析
主要用group by分组,这题和上一题SQL8类似
实现:
select salary as s
from salaries
where to_date='9999-01-01'
group by s
order by s desc