Как сделать выборку последних новостей из подкатегорий?

$sql = $db->query( "SELECT id, title, category, date, alt_name, full_story FROM " . PREFIX . "_post WHERE {$category_id} ORDER BY id DESC LIMIT 10" );
while ($row=$db->get_row($sql)) {

	echo $row['title'];

}

$sql = $db->super_query( "SELECT id, title, category, date, alt_name, full_story FROM " . PREFIX . "_post WHERE {$category_id} ORDER BY id DESC LIMIT 10", true );

if( count( $sql ) ) {
	foreach ($sql as $row) {
		echo $row['title'];
	}
}