Need help with SQL statment

[danbopes]

SELECT u.username, u.user_id, u.user_posts, u.user_from, u.user_website, u.user_email, u.user_icq, u.user_aim, u.user_yim, u.user_regdate, u.user_msnm, u.user_viewemail, u.user_rank, u.user_sig, u.user_sig_bbcode_uid, u.user_avatar, u.user_avatar_type, u.user_allowavatar, u.user_allowsmile, p.*,  pt.post_text, pt.post_subject, pt.bbcode_uid
	FROM " . POSTS_TABLE . " p, " . USERS_TABLE . " u, " . POSTS_TEXT_TABLE . " pt
	WHERE p.topic_id = $topic_id
		$limit_posts_time
		AND pt.post_id = p.post_id
		AND u.user_id = p.poster_id
	ORDER BY p.post_time $post_time_order

This is the current sql that I have, but I need to have it select:

SELECT e.member_race_id, e.member_class_id
FROM eqdkp members
WHERE e.member_id = u.user_eqdkpmem

but the only problem is, I want it to return null for e.member_race_id and e.member_class_id, if there is no match