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

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));

select salaries.emp_no,salaries.salary,salaries.from_date,salaries.to_date,dept_manager.dept_no
from salaries inner join dept_manager
on dept_manager.emp_no = salaries.emp_no
and dept_manager.to_date = '9999-01-01'
and salaries.to_date = '9999-01-01';

SELECT s.*, d.dept_no FROM salaries s ,  dept_manager d

WHERE s.to_date='9999-01-01'

AND d.to_date='9999-01-01'

AND s.emp_no = d.emp_no;