Question

我正在尝试在管理员面板中创建页面，管理员可以从中更改网站设置，例如：site title，default country等。

我在没有ID的数据库settings中创建了表，因为我真的不需要它。它将只会更新一行。没有插入新行。

我在route.php中添加了这一行

Route::get('settings', 'SettingsController@index')->name('admin.settings');
Route::post('settings/update', 'SettingsController@update')->name('admin.settings.update');

这是我在SettingsController.php中的更新功能

public function index()
{
    $settings = Settings::all();
    return view('backend.settings',compact('settings'));
}
public function update( Request $request)
{

    $settings->settings_site_title = $request['site_title'];
    $settings->settings_item_per_page = $request['item_per_page'];
    $settings->settings_default_country = $request['default_country'];
    $settings->settings_max_image_post = $request['max_image_post'];
    $settings->save();

    return redirect()->route('admin.settings')->with('alert-success', ' Success');
}

和表格

 @foreach ($settings as $preferences)
     {!! Form::open(['route' => 'admin.settings.update','files' => true , 'class' =>'form-horizontal']) !!}

              <div class="form-group">
                 {!! Form::label('site_title', 'Site Name', array('class'=> 'col-sm-2 control-label')) !!}
                  <div class="col-sm-10">
                   {!! Form::text('site_title', $preferences->settings_site_title, ['class'=>'form-control', 'placeholder'=>'Enter site name', 'id'=>'site_title']) !!}
                  </div>
                </div>

      ... some more inputs like ^

     {!! Form::close() !!}
 @endforeach

当我提交表单时，我遇到了这个错误：

从空值创建默认对象

更新：型号

class Settings extends Model
{
    protected $table = 'settings';
    public $timestamps = false;

    protected $fillable = [
        'settings_site_title',
        'settings_item_per_page',
        'settings_default_country',
        'settings_max_image_post',
    ];

}

控制器

public function update( Request $request)
{
    $settings = Settings::first(); //missed line
    $settings->settings_site_title = $request['site_title'];
    $settings->settings_item_per_page = $request['item_per_page'];
    $settings->settings_default_country = $request['default_country'];
    $settings->settings_max_image_post = $request['max_image_post'];
    $settings->save();

    return redirect()->route('admin.settings')->with('alert-success', ' Success');
}

Answer 1

您忘记在$settings方法

中设置update变量

public function update( Request $request)
{
    $settings = Settings::first(); //missed line
    $settings->settings_site_title = $request['site_title'];
    $settings->settings_item_per_page = $request['item_per_page'];
    $settings->settings_default_country = $request['default_country'];
    $settings->settings_max_image_post = $request['max_image_post'];
    $settings->save();

    return redirect()->route('admin.settings')->with('alert-success', ' Success');
}

甚至更好更短

public function update( Request $request)
{
    $settings = Settings::first()->update($request->all());

    return redirect()->route('admin.settings')->with('alert-success', ' Success');
}

当然，只有当您使用需要批量分配的列填充fillable模型的Settings属性时，此功能才有效。

class Settings extends Model
{
    // ...
    protected $fillable = [
        'site_title',
        'item_per_page',
        'default_country',
        'max_image_post',
    ];
    // ...
}

修改

试试这个

public function update( Request $request)
{
    $settings = Settings::first(); //missed line
    $settings->settings_site_title = $request->input('site_title');
    $settings->settings_item_per_page = $request->input('item_per_page');
    $settings->settings_default_country = $request->input('default_country');
    $settings->settings_max_image_post = $request->input('max_image_post');
    $settings->save();

    return redirect()->route('admin.settings')->with('alert-success', ' Success');
}

修改

将此添加到您的Settings型号

protected $primaryKey = null;
public $incrementing = false;

Answer 2

if(count($settings)>0){

}

在foreach之前使用此if条件。我认为$ setting变量是空的。

在laravel中选择并更新没有ID的表列

2 个答案: