public function get_list_of_product_info($data = NULL) { $sqlbuilder = new SQLBuilder(); if (is_null($data)) { $sql = mysqli_query($this->db, $sqlbuilder->get_list_of_product_info()); } else { $sql = mysqli_query($this->db, $sqlbuilder->alter_product_query($data)); } $result = NULL; if ($sql && mysqli_num_rows($sql) != 0) { $result = array(); while ($rlt = mysqli_fetch_array($sql, MYSQL_ASSOC)) { $result[] = $rlt; } } return $result; }