EasyJOINs (INNER, LEFT, RIGHT, FULL)

Self JOIN: find employee and their manager name

The query

SQL

SELECT
  e.first_name || ' ' || e.last_name AS employee,
  m.first_name || ' ' || m.last_name AS manager,
  e.job_title
FROM employees e
LEFT JOIN employees m ON e.manager_id = m.emp_id
ORDER BY manager;

Tested against PostgreSQL 16

Note

“SELF JOIN joins a table to itself. Use different aliases (e, m) for clarity.

Tables referenced

employees10 cols