简单PHP代码实现一个orm

abstract class Model
{
    protected $pk = 'id';
    protected $_ID = null;
    protected $_tableName;
    protected $_arRelationMap;
    protected $_modifyMap;
    protected $is_load = false;
    protected $_blForDeletion;
    protected $_DB;

    public function __construct($id = null)
    {
        $this->_DB = @mysql_connect('127.0.0.1', 'root','root');
        $this->_tableName = $this->getTableName();
        $this->_arRelationMap = $this->getRelationMap();
        if (isset($id)) $this->_ID = $id;
    }

    abstract protected function getTableName();

    abstract protected function getRelationMap();

    public function Load()
    {
        if (isset($this->_ID)) {
            $sql = "SELECT ";
            foreach ($this->_arRelationMap as $k => $v) {
                $sql .= '`' . $k . '`,';
            }
            $sql .= substr($sql, 0, strlen($sql) - 1);
            $sql .= " FROM " . $this->_tableName . " WHERE " . $this->pk . " =" . $this->_ID;

            $result = $this->_DB->mysql_query($sql);
            foreach ($result[0] as $k1 => $v1) {
                $member = $this->_arRelationMap[$k1];
                if (property_exists($this, $member)) {
                    if (is_numeric($member)) {
                        eval('$this->' . $member . ' = ' . $v1 . ';');
                    } else {
                        eval('$this->' . $member . ' = "' . $v1 . '";');
                    }
                }
            }
            $this->is_load = true;
        }
    }

    public function __call($method, $param)
    {
        $type = substr($method, 0, 3);
        $member = substr($method, 3);
        switch ($type) {
            case "get":
                return $this->getMemeber($member);
                break;
            case "set";
                return $this->setMember($member, $param[0]);
        }
        return false;
    }

    public function setMember($key, $val)
    {
        if (!property_exists($this, $key)) {
            if (is_numeric($val)) {
                $str = '$this->' . $key . ' = ' . $val . ';';
            } else {
                $str = '$this->' . $key . ' = "' . $val . '";';
            }
            eval($str);
            $this->_modifyMap[$key] = $val;
        } else {
            return false;
        }
    }

    public function getMemeber($key)
    {
        if (!$this->is_load) {
            $this->Load();
        }
        if (property_exists($this, $key)) {
            eval('$res = $this->' . $key . ';');
            return $this->$key;
        }
        return false;
    }

    public function save()
    {
        $field = '';
        $values = '';
        if (isset($this->_ID)) {
            $sql = "UPDATE " . $this->_tableName . ' SET ';
            foreach ($this->_arRelationMap as $k2 => $v2) {
                if (array_key_exists($k2, $this->_modifyMap)) {
                    eval('$val = $this->' . $v2 . ';');
                    $sql_update .= $v2 . " = " . $val;
                }
            }
            $sql .= substr($sql_update, 0, strlen($sql_update));
            $sql .= ' WHERE ' . $this->pk . ' = ' . $this->_ID;
        } else {
            $sql = "INSERT INTO " . $this->_tableName . " (";
            foreach ($this->_arRelationMap as $k3 => $v3) {
                if (array_key_exists($k3, $this->_modifyMap)) {
                    eval('$val = $this->' . $v3 . ';');
                    $field .= "`" . $k3 . "`,";
                    $values .= '"'.$val.'",';
                }
            }
            $fields = substr($field, 0, strlen($field) - 1);
            $vals = substr($values, 0, strlen($values) - 1);
            $sql .= $fields . " ) VALUES (" . $vals . ")";
        }
        echo $sql;
        return $this->_DB->query($sql);
    }

    public function __destory()
    {
        if (isset($this->ID)) {
            $sql = "DELETE FROM " . $this->_tableName . " WHERE " . $this->pk . " = " . $this->_ID;
            //$this->_DB_query($sql);
        }
    }
}

class User extends Model
{
    protected function getTableName()
    {
        return "ycq_bsfphb_new_service";
    }

    protected function getRelationMap()
    {
        return array(
            'id' => 'id',
            'server_id' => 'server_id',
            'server_name' => 'server_name'
        );
    }

    public function getDB()
    {
        return 'test';
        //return $this->_DB;
    }
}



#增
//$UserIns = new User();
// $UserIns->setserver_id(118);
// $UserIns->setserver_name('特别服务器');
// $UserIns->setopen_time(1613664000);
// $UserIns->save();

#改
// $UserIns = new User(1);
// $UserIns->setserver_id(118);
// $UserIns->save();

//获取id=1记录的 server_id的值
$UserIns = new User(1);
$re = $UserIns->getserver_id();