Table schema:
CREATE TABLE Engineer_Visits (contact_staff_id VARCHAR); CREATE TABLE Staff (staff_name VARCHAR, staff_id VARCHAR)

Question: How many engineers did each staff contact? List both the contact staff name and number of engineers contacted.
SQL: SELECT T1.staff_name, COUNT(*) FROM Staff AS T1 JOIN Engineer_Visits AS T2 ON T1.staff_id = T2.contact_staff_id GROUP BY T1.staff_name