Niu Ke.com database SQL combat 03-find all the information of the latest employees

Niu Ke.com database SQL combat 03-find all the information of the latest employees

Title description

Find the current (to_date = '9999-01-01') leadership salary details of each department and its corresponding department number 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`));

Enter description:

no

Output description:

emp_no	birth_date	birth_date	last_name	last_name	hire_date
10008	1958-02-19	Saniya	Kalloufi	M	1994-09-15

emp_no	salary	from_date	to_date	dept_no
10002	72527	2001-08-02	9999-01-01	d001
10004	74057	2001-11-27	9999-01-01	d004
10005	94692	2001-09-09	9999-01-01	d003
10006	43311	2001-08-02	9999-01-01	d002
10010	94409	2001-11-23	9999-01-01	d006

My answer

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

My method did not pass the test, personally feel that the problem is not given to the table data, and it is not clear

After the test, it was found that the s and d tables could be passed by changing the position. . .

I think the best answer

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;