关于DbConnection类保存二进制数据bug

public function bind($para, $value)
    {
        if (is_string($para)) {
            $this->parameters[sizeof($this->parameters)] = ":" . $para . "\x7F" . $value;
        } else {
            $this->parameters[sizeof($this->parameters)] = $para . "\x7F" . $value;
        }
    }