SQL self join: employees who earn more than their manager

Why the usual answer is wrong

SELECT e.name
FROM employees e
JOIN employees m ON e.emp_id = m.manager_id
WHERE e.salary > m.salary;

The join is the wrong way round: it pairs each person with the people who report to them, so it lists managers who earn more than someone in their team (Asha, Ravi, Neha).

The answer

SELECT e.name
FROM employees e
JOIN employees m ON e.manager_id = m.emp_id
WHERE e.salary > m.salary;

Give the table two names: e for the employee, m for the manager. Each employee row points to its manager through manager_id, so the join is e.manager_id = m.emp_id.

Say it out loud before you write it: "for each employee, find their manager". The ON clause then writes itself. Asha has no manager, so the join drops her, which is what we want here.