title: How to find mulitiple column by using join instead of group by?
body: <p><strong>This is used for subquery . But i need this by using join</strong></p>
  
  <pre><code>select first_name,department_id,salary from employees
  where (department_id , salary) in (select department_id ,max (salary) as max_sal from employees
  group by department_id);  
  </code></pre>