Question 16096 in Laravel Question posted in
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Laravel. Property does not exist on this collection instance. Relation error

I try to create relations between different tables in my database and get data from these tables, but I got an error: Property does not exist on this collection instance.

This is my code:

Migrations files:

Schema::table('books', function (Blueprint $table) {
        $table->foreignId('author_id')->constrained('authors')->onUpdate('cascade')->onDelete('cascade');
    });

In ModelAuthors:

public function books () {
    return $this->hasMany('AppModelsBooks');  
}

In ModelBooks:

public function author() {
    return $this->belongsTo('AppModelsAuthors'); 
}

In AuthorsController:

public function index () {
    
    $authors = Authors::all(); 
    return dd($authors->books); 
     
}

In BooksController:

public function index () {
    
    $books = Books::all(); 
    return  dd($books->author); 
    
}

If someone has an idea how to fix this, I will be very grateful.

Tags:

4

Answers


  1. Chosen as BEST ANSWER
    0

    Thank you guys! In my case, the right solution was :

    In model:

    public function author() { return $this->belongsTo('AppModelsAuthors', 'author_id'); }

    And in controller :

    $books = Books::with('author')->get();

    And in view file I added:

    @foreach
            <li>{{ $book->title}}</li>                    
            <li>{{ $book->author->name}}</li>
            @endforeach

    Thank you again. The topic can be closed )))))


  2. 0

    Your models is right but you wrong when you call $authors->books because $authors is collection of your Authors model not object of Author. If your want check your relationship you can do with this example:

    public function index () {
    
    $authors = Authors::latest()->first();; 
    dd($authors->books); 
     
}
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  3. 0

    Your relation between Authors and books is one-to-many so an Author hasMany books (like you have correctly stated in the model relation).

    The output of this is a collection so you can not access it that way, instead you need to loop it like:

    public function index () {
    $authors = Authors::all(); 
    $authors->books->each(function ($book) {
      print_r($book);
    }
}

    In case you want to retrieve the books of a single Author you can return a single model instance for the Author like:

    public function index () {
    $author = Authors::where('id',1)->first(); 
    print_r($author->books);
}
    Login or Signup to reply.
  4. 0

    If you want to have all authors with their books, use eager loading with()

    public function index () {
    
    $authors = Authors::with('books')->get(); 
    return dd($authors); 
     
}

    If you wants all the books with their respective author

    public function index () {
    
    $books = Books::with('author')->get(); 
    return  dd($books); 
    
}

    When you iterate the collection (like an array) in your blade, you can then access the relation

    @foreach($books as $book)
    <span>{{$book->author->name}}</span>
@endforeach

    If you just want to get a dd of the books of one author you can do it like this

    public function index () {
    
    $authors = Authors::all();
    // $authors is a collection of models (think of it as an advanced array)
    // To get one of the models, you can iterate them with a loop or, for example, take the first one with "->first()"
    //$authors->first() is an instance of the model "Author" class

    return dd($authors->first()->books); 
    // $authors->first()->books is now a collection of models of "Book" class
}
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