'servers' => array(
        'db_tradeapi' => array( //服务器标记
            'pdo'      => 'pgsql',//数据库类型
            'host'     => 'XX', //数据库域名
            'name'     => 'XX', //数据库名字
            'user'     => 'XX', //数据库用户名
            'password' => 'XX', //数据库密码
            'port'     => '5432', //数据库端口
            'charset'  => 'UTF8', //数据库字符集
        ),
    ),

 protected function createPDOBy($dbCfg)
    {
        $dsn = sprintf('%s:dbname=%s;host=%s;port=%d',
            isset($dbCfg['pdo']) ? $dbCfg['pdo'] : 'mysql',//添加数据库类型标识判断，默认是MySQL
            $dbCfg['name'],
            isset($dbCfg['host']) ? $dbCfg['host'] : 'localhost',
            isset($dbCfg['port']) ? $dbCfg['port'] : 3306
        );
        $charset = isset($dbCfg['charset']) ? $dbCfg['charset'] : 'UTF8';

        $pdo = new PDO(
            $dsn,
            $dbCfg['user'],
            $dbCfg['password']
        );
        $pdo->exec("SET NAMES '{$charset}'");

        return $pdo;
    }