อาจารย์ที่เล่นทั้งพายเรือแคนูและพายเรือคายัคชื่ออะไร ไม่จำเป็นต้องใช้ทุกโต๊ะ
What are the first names of the faculty members playing both Canoeing and Kayaking?It is not neccessary to use all the tables.
 faculty:  facid [ number]  lname [ text]  fname [ text]  rank [ text]  sex [ text]  phone [ number]  room [ text]  building [ text] 
SELECT T1.lname FROM faculty AS T1 JOIN faculty_participates_in AS T2 ON T1.facid = T2.facid JOIN activity AS T3 ON T2.actid = T2.actid WHERE T3.activity_name = 'Canoeing' INTERSECT SELECT T1.lname FROM faculty AS T1 JOIN faculty_participates_in AS T2 ON T1.facid = T2.facid JOIN activity AS T3 ON T2.actid = T2.actid WHERE T3.activity_name = 'Kayaking'