use Think\Model; $ret = $Model->query("select * from think_user where score >= " . $score);

use Think\Model; 

        //http://localhost/thinkphp323/index.php/home/User/query_score/score/20
    public function query_score($score=60){    
        $Model = new \Think\Model(); // 实例化一个model对象 没有对应任何数据表
        $ret = $Model->query("select * from think_user where score >= " . $score);
        var_dump($ret);
    }

array (size=3)
  0 => 
    array (size=4)
      'id' => string '1' (length=1)
      'username' => string 'jim' (length=3)
      'score' => string '100' (length=3)
      'create_time' => string '0' (length=1)
  1 => 
    array (size=4)
      'id' => string '2' (length=1)
      'username' => string 'tom' (length=3)
      'score' => string '100' (length=3)
      'create_time' => string '0' (length=1)
  2 => 
    array (size=4)
      'id' => string '3' (length=1)
      'username' => string 'lucy' (length=4)
      'score' => string '23' (length=2)
      'create_time' => string '0' (length=1)