What is all the information regarding employees who are managers?
SELECT DISTINCT * FROM employees AS T1 JOIN departments AS T2 ON T1.department_id  =  T2.department_id WHERE T1.employee_id  =  T2.manager_id
employees who are managers refers to matching employee_id with manager_id; all the information = SELECT *; DISTINCT is used to remove duplicates; JOIN is used to combine rows from two or more tables based on a related column between them.