php - 提供的参数无效 Codeigniter

Question

我的程序无法正常工作，我不知道该怎么办:S

我收到此错误消息:

看看这个:

这是我的代码:我的 Controller 文件(主页):

    <?php

    class Home extends CI_Controller{

         public function __construct(){
             parent::__construct();

             $this->load->model("Crudmodel");

        }


 public function index(){

    # get all data in Study table
    $selectStudys = $this->Crudmodel->selectStudys();


    foreach ($selectStudys as $key => $study) 
    {
        # get UserNames
        $user = $this->Crudmodel->getName($study['user_id']);

        #get Subject Names
        $subject = $this->Crudmodel->getSubName($study['subject_id']);


        #append both NEW VALUES to same array

        if(!empty($user[0]['username'])){
        $data[$key]['user_id'] = $user[0]['username'];
        // your main problem can be this. may be it is not getting value from query this is why we have put validation on model function and error handler condition here
        }else{
         $data[$key]['user_id'] = ''; // or anything as your else condition you can use as error handler 
        }
        if(!empty($subject[0]['name'])){
        $data[$key]['subject_id'] = $subject[0]['name'];
        // your main problem can be this. may be it is not getting value from query this is why we have put validation on model function and error handler condition here
        }else{
           $data[$key]["subject_id"] = "";
          // or anything you can use as error handler
        }

    }


    $data['records'] = $selectStudys;
    $this->load->view('home', $data);

}

}
?>

粗略模型:

       class Crudmodel extends CI_Model{

        public function __construct(){
         parent::__construct();

         $this->load->database();

        }


        function selectStudys()
{
    $query= $this->db->query("SELECT * FROM cursadas");
    if($query->num_rows()>0){
       $result = $query->result_array();
     }else{
      $result = "";
          // or anything you can use as error handler
      return $result;
    }
}

function getName($name)
{
    $query= $this->db->query("SELECT username FROM usuarios WHERE id = $name ");
    if($query->num_rows()>0){
    $result = $query->result_array();
    }else{
    $result = "";
          // or anything you can use as error handler
    return $result;
  }
}

现在不知道该怎么办:(

希望你能帮助我:S

Answer 1

问题出在模型上。您只返回 else 内的内容。修复很简单，移动return即可。

如果没有行，您可能应该返回一个空数组。那么 foreach 仍然会有一些东西可以使用 - 即使它是空的。如果给定一些不能在循环中使用的东西(例如字符串)，foreach 将会阻塞。

function selectStudys()
{
    $query= $this->db->query("SELECT * FROM cursadas");
    if($query->num_rows()>0){
       $result = $query->result_array();
     }else{
      $result = array();
    }
    return $result;
}