查找当前薪水详情以及部门编号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,salary,salaries.from_date,salaries.to_date,dept_no from salaries,dept_manager where salaries.emp_no=dept_manager.emp_no and salaries.to_date='9999-01-01' and dept_manager.to_date='9999-01-01'