How to Find Employee Pairs in the Same Department?

SELECT e1.name AS Employee1, e2.name AS Employee2 FROM employees e1 JOIN employees e2 ON e1.department_id = e2.department_id WHERE e1.id < e2.id;

This SQL query retrieves pairs of employees who belong to the same department by joining the employees table with itself.

1. Select two instances of the employees table, aliased as e1 and e2.
2. Join the two instances on the department_id to find employees in the same department.
3. Use a WHERE clause to ensure that each pair is unique (e1.id < e2.id).
4. Return the names of both employees in the resulting pairs.

• Employees with the same name in the same department will be included in the results.
• Departments with only one employee will not produce any pairs.
• If there are no employees in the table, the query will return an empty result set.
• Employees in different departments will not be matched.