trying to convert a fuction that uses mysqli to use the wpdb class

Hi guys i got a bit of a problem, I’m trying to make a set of function to pull items from an added table and build an interface to sort products with. the problem is that i can’t figure out how to get the wpdb class to work like mysqli. i wrote it with mysqli and it worked till i updated to 2.8.2 and i figure useing mysql over wordpress is a bit of a hack. anyway here are my two functions that talk (or at least use to) to the database.

function get_product_manufacturers($var=NULL)
{
	global $wpdb;
	$query = 'SELECT * FROM akt_products ORDER BY id asc';
	$results = $wpdb->query($query, 'OBJECT');
	if($results->num_rows) {
		while($row = $results->fetch_object())
		{
			$manufacturers_all[$row->id] = stripcslashes(htmlspecialchars_decode($row->manufacturer));
		}
		$manufacturers = array_unique($manufacturers_all);
		if($var=='all')
		{
			return $manufacturers_all;
		}else{
			return $manufacturers;
		}
	}
}

function get_product_categories($var=NULL)
{
	//get the catergories
	global $wpdb;
	$query = 'SELECT * FROM akt_products ORDER BY id asc';
	$results = $wpdb->query($query);
	if($results->num_rows) {
		while($row = $results->fetch_object())
		{
			$categories_all[$row->id] = stripcslashes(htmlspecialchars_decode($row->category));
		}
	}

	//build the array - NOT UNIQUE!
	$manufacturers_all = get_product_manufacturers('all');
	if($var==NULL):
		break;
	elseif($var=='all'):
		$categories = array_unique($categories_all);
	else:
		$i=0;
		foreach($manufacturers_all as  $key => $manufacturer)
		{
			if($manufacturer != $var)
			{}
			elseif($manufacturer == $var)
			{
				$categories_current[$i] = $categories_all[$key];
			}
			$i++;
		}
		$categories = array_unique($categories_current);
	endif;
	return $categories;
}