Help needed on first try at Database Query!

[EvilCrow]

I wasn't sure if this is the right section to post but I'll try here...

I'm trying to make a Database query, This will be my first one, So please be nice..

ok heres what I'm trying to do.. I have a site I'm doing for a support group. I have a userfield that members can choose a number, What I need is a database query that will add-up all the numbers and give a total...

Heres my failed stab at it..

	$result_allweight = $DB_site->query("
		SELECT * FROM " . TABLE_PREFIX . "userfield $searchclause ORDER BY field7
	");

	$weightcount = $DB_site->num_rows($result_allweight);

I need the query to go inside the "Userfield" and count the numbers inside "field7" and give me a total for all..
btw, This code works but its only giving me the total of members not whats inside the "Field7" Table!