Database: dog_kennels
Question: Which professionals have done at least two treatments? List the professional's id, role, and first name.
SQL:
SELECT T1.professional_id ,  T1.role_code ,  T1.first_name FROM Professionals AS T1 JOIN Treatments AS T2 ON T1.professional_id  =  T2.professional_id GROUP BY T1.professional_id HAVING count(*)  >=  2