SELECT member_name FROM member WHERE party_id  =  3 INTERSECT SELECT member_name FROM member WHERE party_id  =  1
Show the member names which are in both the party with id 3 and the party with id 1.
SELECT member_name FROM member WHERE party_id = 3 INTERSECT SELECT member_name FROM member WHERE party_id = 1
select member_name from member where party_id = value intersect select member_name from member where party_id = value
Show the member names which are in both the party with id 3 and the party with id 1 .