Full Outer Join easy
```\nselect\nisnull(e.employee_id, s.employee_id) as employee_id\nfrom\nemployees e full outer join salaries s on e.employee_id=s.employee_id\nwhere e.name IS N
```\nselect\nisnull(e.employee_id, s.employee_id) as employee_id\nfrom\nemployees e full outer join salaries s on e.employee_id=s.employee_id\nwhere e.name IS NULL or s.salary is null\norder by isnull(e.employee_id, s.employee_id) asc
['MS SQL Server']