Laravel关系没有结果

Question

I have a "booking" that has relationships with the "markets" and "stalls"

I have the Selects working on the create form but the index blade is not displaying correctly.

It should take the "id" and convert it to the "name" field as in the below

 <td>{{$user->role ? $user->role->name : 'User has no role'}}</td>

And this displays correctly with the following Model code: public function role(){

    return $this->belongsTo('App\Role');
}

and this is my "Bookings" Model:

public function marketdate(){

    return $this->belongsTo('App\Markets');
}

public function stallstype() {

    return $this->belongsTo('App\Stalls');
}

With the following on the index.blade:

...
<td>{{$booking->marketdate ? $booking->marketdate->date : '-' }}</td>
<td>{{$booking->stallstype ? $booking->stallstype->name : '-'}}</td>
...

But this just shows the "-" when it renders the page

the ID's that are stored in the database are correct and do correlate it is just not displaying correctly.

One other thing, the table schemas are as follows:

Stalls table:

Schema::create('stalls', function (Blueprint $table) {
        $table->increments('id');
        $table->string('name');
        $table->integer('cost');
        $table->timestamps();
    });

Markets table:

  Schema::create('markets', function (Blueprint $table) {
        $table->increments('id');
        $table->string('date');
        $table->integer('is_active');
        $table->timestamps();
    });

The error is:

at PhpEngine-    >evaluatePath('C:\xampp\htdocs\moowoos\storage\framework\views/3bcb71b43fffee7f9 a9edf18bfb397ab94380507.php', array('__env' => object(Factory), 'app' => object(Application), 'errors' => object(ViewErrorBag), 'bookings' => object(Collection), 'markets' => array('Saturday 4th March', 'Saturday 5th April', 'Saturday 6th May', 'Saturday 7th June', 'Saturday 8th July', 'Saturday 8th July'), 'stalltype' => array('Preloved', 'Craft', 'Business'))) in compiled.php line 15361
at CompilerEngine->get('C:\xampp\htdocs\moowoosesources\views/admin/bookings/index.blade.php', array('__env' => object(Factory), 'app' => object(Application), 'errors' => object(ViewErrorBag), 'bookings' => object(Collection), 'markets' => array('Saturday 4th March', 'Saturday 5th April', 'Saturday 6th May', 'Saturday 7th June', 'Saturday 8th July', 'Saturday 8th July'), 'stalltype' => array('Preloved', 'Craft', 'Business'))) in compiled.php line 15193

Which shows that it is returning the array

Answer 1

It seems that Eloquent is not able to load related models. As you use lists() to load your other models I assume you do the same for Business model.

When you call lists('name', 'id'), you're telling Eloquent to load only those 2 fields from the database. So, if you use that to load Business models as well, you're not fetching marketdate_id nor stallstype_id, that's why Eloquent is not able to load the related models.

Make sure that foreign key columns are passed to lists() method if you want to load related models:

Business::lists('name', 'id', 'stalltype_id', 'marketdate_id')->all();