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MySQL Self Join
A self join in MySQL is a join operation where a table is joined with itself. It is useful when you need to compare rows within the same table.
Example:
SELECT e1.employee_id, e1.employee_name, e2.manager_name
FROM employees e1
JOIN employees e2 ON e1.manager_id = e2.employee_id;This query retrieves the employee ID, employee name, and manager name by joining the employees table with itself based on the manager ID.
Self joins are commonly used to create hierarchical relationships or to compare records within the same table.