Interview › Self-join

SQL interview: employee / manager self-join

The manager is a row in the same table. Alias it twice.

Prompt. List each staff member and their manager’s name. Top person has no manager.

Hint: LEFT JOIN Staff m ON m.staff_id = s.manager_id

Your T-SQL

SELECT s.staff_id, s.full_name,
       m.full_name AS manager_name
FROM Staff s
LEFT JOIN Staff m ON m.staff_id = s.manager_id;

A tree walk (all bosses above) is a recursive CTE, not one self-join.

Then write it on a ticket

Monday is free. A colleague asks, you type, we mark it.