PHP MYSQL 救命呀！该如何处理

PHP MYSQL 救命呀！！！！
ThinkPHP框架
  public function select() {
  $db_dsn = "mysql://root:guozhixin@localhost:3306/my_table";
  $db = new Db($db_dsn);
  echo $db->execute("select * from think_person");
  }

http://127.0.0.1/iBaby/iBaby/index.php/Index/select

数据库设置全对，怎么就是访问以后是一片空白呢？有人能帮帮我吗？

------解决方案--------------------
echo $db->execute("select * from think_person");

你改成： dump($db->execute("select * from think_person")); 试试。

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如下为数据库配置：
//'配置项'=>'配置值'
'DB_TYPE'=>'mysql',
'DB_HOST'=>'localhost',
'DB_NAME'=>'test',
'DB_USER'=>'root',
'DB_PWD'=>'123456',
'DB_PORT'=>'3306',
'DB_PREFIX'=>'think_',
写一个Action:
function get_data()
{
$db=M('User');
dump($db->where('id=1')->select());
}