查询给出错误：试图获取非对象的属性

Question

我收到此错误：

Trying to get property of non-object

当我尝试使用 CodeIgniter 搜索学生证时。

这是我的控制器代码：

public function get_stud_info($id = "")
{
    $stud_info = $this->m_stud_info->get_by_ID($id);

    $data['IDno'] = $stud_info->IDno;
    $data['LName'] = $stud_info->LName;
    $data['FName'] = $stud_info->FName;
    $data['Course'] = $stud_info->Course;
    $data['Year'] = $stud_info->Year;
    $data['Club_num'] = $stud_info->Club_num;

    $this->load->view('view_stud_info', $data);
}

这是我的型号代码：

public function get_by_ID($ID)
{
    $query = $this->db->where('IDno', $ID)->limit(1)->get('stud_info');

    if($query->num_rows() > 0)
    {
        return $query->row();
    }
    else
    {
        return array();
    }
}

这是我的视图代码：

<?php
    echo "IDNo: $IDno <br/>" ;
    echo "LName: $LName <br/>" ;
    echo "FName: $FName <br/>" ;
    echo "Course: $Course <br/>" ;
    echo "Year: $Year <br/>" ;
    echo "Club_num: $Club_num <br/>" ;
?>

Answer 1

当模型为你返回空数组时会出现错误，所以在你访问它之前检查模型是否返回任何值。

$stud_info = $this->m_stud_info->get_by_ID($id);
if($stud_info) {
    $data['IDno'] = $stud_info->IDno;
    $data['LName'] = $stud_info->LName;
    $data['FName'] = $stud_info->FName;
    $data['Course'] = $stud_info->Course;
    $data['Year'] = $stud_info->Year;
    $data['Club_num'] = $stud_info->Club_num;
} else {
    // assign all values to null here
    $data['IDno'] = "";
    ...
}

Answer 2

这个怎么样，我想对你来说会更简单更容易。

$stud_info = $this->m_stud_info->get_by_ID($id);
if($stud_info) {
$data['IDno'] = isset($stud_info->IDno) ? $stud_info->IDno : '';
...
}