Die Beziehung in der Datentabelle ist leer

Question

Ich erhalte diesen Fehler in DataTables: DataTables-Warnung: Tabellen-ID=DataTables_Table_0 – Ausnahmemeldung:

Es wird versucht, die Nulleigenschaft „name“ zu lesen.

Obwohl jede position_id eine ID aus der Positionstabelle hat, sollte sie daher nicht leer sein. Wenn jemand helfen möchte, wäre ich dankbar. Mein Modell:

public function position()
    {
        return $this->belongsTo(Position::class);
    }

Mein Controller:

class EmployeeController extends Controller
{
    public function index(Request $request)
    {
        if ($request->ajax()) {
            $data = Employee::with('position')->select('id','name','email')->get();
            return Datatables::of($data)->addIndexColumn()
            ->addColumn('position', function (Employee $employee) {
                return $employee->position->name;
            })->addColumn('action', function($data){
                    $button = '<button type="button" name="edit" id="'.$data->id.'" class="edit btn btn-primary btn-sm"> <i class="bi bi-pencil-square"></i>Edit</button>';
                    $button .= '   <button type="button" name="edit" id="'.$data->id.'" class="delete btn btn-danger btn-sm"> <i class="bi bi-backspace-reverse-fill"></i> Delete</button>';
                    return $button;
                })
                ->make(true);
        }

        return view('admin.employees.index');

    }
}

Skript:

$(document).ready(function() {
        var table = $('.user_datatable').DataTable({
            processing: true,
            serverSide: true,
            ajax: "{{ route('admin.employees.index') }}",
            columns: [
                {data: 'id', name: 'id'},
                {data: 'name', name: 'name'},
                {data: 'email', name: 'email'},
                {data: 'position', name: 'position.name'},
                {data: 'action', name: 'action', orderable: false, searchable: false},
            ]
        });

Migrieren:

public function up()
    {
        Schema::create('employees', function (Blueprint $table) {
            $table->id();
            $table->string('name');
            $table->foreignId('position_id')->nullable();
            $table->string('phone_number');
            $table->date('recruitment_date');
            $table->string('email')->unique();
            $table->string('image_path')->nullable();
            $table->string('payment');
            $table->timestamps();
            $table->string('admin_created_id')->nullable();
            $table->string('admin_updated_id')->nullable();
        });
    }

Answer 1

此错误意味着当 Datatable 尝试从 $data 获取数据时，没有集合或数组将其定位在 get() 方法内

{ collection[0]{
0 => 'Models/Employees'[0],
1 => 'Models/Employees'[1]
}

所以，当您查看 $raw 时，上面的返回没有位置或属性

从那时起，我们将把控制器更改为这样

public function index(Request $request)
    {
        if ($request->ajax()) {
            $data = Employee::query()->with('position')->select('id','name','email')->get();
            return Datatables::of($data)->addIndexColumn()
            ->addColumn('position', function (Employee $employee) {
                return $employee->position->name;
            })->addColumn('action', function($data){
                    $button = ' Edit';
                    $button .= '     Delete';
                    return $button;
                })
                ->make(true);
        }

        return view('admin.employees.index');

    }

如果不起作用，您可以尝试更改数据库查询 但为此我需要转储 $data 您可以在浏览器中的 Inspect 元素的 Network 部分中看到结果 dd($data);

Answer 2

问题是因为选择。似乎如果你要使用关系，你必须在选择中添加外键（在我的例子中是“position_id”），或者完全删除它并只使用 get 。感谢所有在评论中提供帮助的人。