查找各个部门当前(to_date='9999-01-01')领导当前薪水详情以及其对应部门编号dept_no之SQL实现

题目描述

查找各个部门当前(to_date='9999-01-01')领导当前薪水详情以及其对应部门编号dept_no
CREATE TABLE `dept_manager` (
`dept_no` char(4) NOT NULL,
`emp_no` int(11) NOT NULL,
`from_date` date NOT NULL,
`to_date` date NOT NULL,
PRIMARY KEY (`emp_no`,`dept_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`));

 

SQL实现

select s.emp_no , s.salary, s.from_date, s.to_date, d.dept_no
from salaries as s
left join dept_manager as d
on s.emp_no=d.emp_no
where s.to_date = '9999-01-01'
and d.to_date='9999-01-01';

关键：以salaries为主表；