每周一练（19）

查找所有员工入职时候的薪水情况，给出emp_no以及salary， 并按照emp_no进行逆序

 

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`));

 

select e.emp_no, s.salary
from employees e, salaries s
where e.emp_no = s.emp_no
and e.hire_date = s.from_date
order by e.emp_no desc;

 

 

查找薪水涨幅超过15次的员工号emp_no以及其对应的涨幅次数t

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`));

 

select emp_no, count(*) as t
from salaries
group by emp_no
having t > 15;