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

Which faculty members advise two ore more students? Give me their faculty ids.
SELECT T1.facid FROM faculty AS T1 JOIN student AS T2 ON T1.facid = T2.advisor GROUP BY T1.facid HAVING COUNT(*) >= 2
SELECT "T1"."facid" FROM "faculty" AS "T1" JOIN "student" AS "T2" ON "T1"."facid" = "T2"."advisor" GROUP BY "T1"."facid" HAVING COUNT(*) >= 2