/** * Get recommended items by user's id * * @param int $userId * @param int $limit * @return array */ public function getRecommendedItemsByUser($userId, $limit = 20) { $sql = 'select s.item_id2 from oso_slope_one s,oso_user_ratings u where u.user_id = ' . $userId . ' and s.item_id1 = u.item_id and s.item_id2 != u.item_id group by s.item_id2 order by sum(u.rating * s.times - s.rating)/sum(s.times) desc limit ' . $limit; $Database = new DateBase($this->_config['host'], $this->_config['username'], $this->_config['password'], $this->_config['dbname']); $Database->Connect(); $Database->Query = $sql; $Database->Query(); while ($row = mysql_fetch_array($Database->queryResult)) { $user[] = $row[0]; } $Database->Close(); return $user; }