CREATE TABLE activity (actid NUMBER, activity_name CLOB)
CREATE TABLE student (stuid NUMBER, lname CLOB, fname CLOB, age NUMBER, sex CLOB, major NUMBER, advisor NUMBER, city_code CLOB)
CREATE TABLE participates_in (stuid NUMBER, actid NUMBER)
CREATE TABLE faculty_participates_in (facid NUMBER, actid NUMBER)
CREATE TABLE faculty (facid NUMBER, lname CLOB, fname CLOB, rank CLOB, sex CLOB, phone NUMBER, room CLOB, building CLOB)

Find the ids of the students who participate in Canoeing and Kayaking.
SELECT T1.stuid FROM participates_in AS T1 JOIN activity AS T2 ON T2.actid = T2.actid WHERE T2.activity_name = 'Canoeing' INTERSECT SELECT T1.stuid FROM participates_in AS T1 JOIN activity AS T2 ON T2.actid = T2.actid WHERE T2.activity_name = 'Kayaking'
SELECT "T1"."stuid" FROM "participates_in" "T1" JOIN "activity" "T2" ON "T2"."actid" = "T2"."actid" AND "T2"."activity_name" = 'Canoeing' INTERSECT SELECT "T1"."stuid" FROM "participates_in" "T1" JOIN "activity" "T2" ON "T2"."actid" = "T2"."actid" AND "T2"."activity_name" = 'Kayaking'