php简单的ActiveRecorde

<?php
abstract class DataRecord {
        private static $db; // MySQLi-Connection, same for all subclasses
        private static $table = array(); // Array of tables for subclasses
        
        public static function init($classname, $table, $db = false) {
                if (!($db === false)) self::$db = $db;
                self::$table[$classname] = $table;
        }
        
        public static function getDB() { return self::$db; }
        public static function getTable($classname) { return self::$table[$classname]; }
}

class dbMysqli extends DataRecord {
        public static function fetchFromDB() {

                $temp = parent::getDB()->query('select * from '.parent::getTable('dbMysqli').';');
    while ($row = $temp->fetch_object()){
      $result[] = $row;
    }

                return $result; // An array of UserDataRecord objects
        }
}

class dbPdo extends DataRecord {
        public static function fetchFromDB() {

                $temp = parent::getDB()->query('select * from '.parent::getTable('dbPdo').';');
    foreach($temp as $value){
      $result[]=$value;
    }
                return $result; // An array of UserDataRecord objects
        }
}
/*
$db = new mysqli('localhost', 'root', '', 'mysql');

dbMysqli::init('dbMysqli', 'user', $db);
$users = dbMysqli::fetchFromDB();
*/


$dsn = 'mysql:dbname=mysql;host=127.0.0.1';
$user = 'root';
$password = '';

try {
        $db = new PDO($dsn, $user, $password);
} catch (PDOException $e) {
        echo 'Connection failed: ' . $e->getMessage();
}

dbPdo::init('dbPdo', 'user', $db);
$users = dbPdo::fetchFromDB();

var_dump($users);

?>