Laravel Invalid argument supplied for foreach - php

Model Doctor
class Doctor extends Model
{
public function addresses() {
return $this->belongsTo(Doctor::class);
}
}
Model Address
class Address extends Model
{
public function doctors() {
return $this->hasMany(Address::class);
}
}
DoctorsController
class DoctorsController extends Controller
{
public function index()
{
$doctors = Doctor::with('addresses')->get();
return view('doctors.index',compact('doctors'));
}
}
Blade
#foreach($doctors as $doctor)
{{ $doctor->name }}
#foreach($doctor->addresses as $address)
{{ $address->city }}
#endforeach
#endforeach
I have an error
Invalid argument supplied for foreach()
I tried to make a relation between Doctor and Address, but it doesn't work. If i try dd($doctor->addresses) i have null.

You reference the same class in your relations ("Doctor belongs to Doctor"), that probably cannot work.
Try:
class Doctor extends Model
{
public function addresses() {
return $this->hasMany(Address::class);
}
}
class Address extends Model
{
public function doctors() {
return $this->belongsTo(Doctor::class);
}
}

does it make sense that a doctor has many addresses and a address has many doctors? basing on your models you do have a many to many relationship between doctors and addresses?
Why not you can do it this way. a doctor has many addresses? so one to many relationship
then your models would be like this way.
Doctor model
class Doctor extends Model
{
public function addresses() {
return $this->hasMany('App\Address','DoctorId');// you need to indicate the foreign key if you didn't follow the laravel naming convention
}
}
address model
class Address extends Model
{
public function doctor() {
return $this->hasOne('App\Doctor','DoctorId');// you need to indicate the foriegn key if you didn't follow the Laravel naming convention
}
}
you controller
class DoctorsController extends Controller
{
public function index()
{
$doctors = Doctor::all();//or Doctor::where('something','=','value')->get();
return view('doctors.index',compact('doctors'));
}
}
your view
#foreach($doctors as $doctor)
{{ $doctor->name }}
#foreach($doctor->addresses as $address)
{{ $address->city }}
#endforeach
#endforeach

Related

Laravel hasManyThrough polymorphic table not working

I've following relationship:
class Project extends Model
{
public function invitors()
{
return $this->hasMany(Invitation::class)
}
}
// User model
class User extends Model
{
public function invitations()
{
return $this->morphMany('App\Invitation', 'invitee');
}
}
// Business Model
class Business extends Model
{
public function invitations()
{
return $this->morphMany('App\Invitation', 'invitee');
}
}
// Invitation model
class Invitation extends Model
{
public function invitee()
{
return $this->morphTo();
}
public function project()
{
return $this->belongsTo(Project::class);
}
}
What I want is to get project invitors (users, and businesses). When I use from $project->invitors->invitee its not working.
In your example $project->invitors is a collection of Invitation instances, and it hasn't property invitee. You can use helper pluck to loop $project->invitors and get their invitees:
$invitees = $project->invitors->pluck('invitee');
As a response to the first comment:
to get specific attributes of fetched linked models ("invitee") you can specify accessors:
class Business extends Model
{
...
public function getInviteeNameAttribute() {
return $this->name;
}
}
class User extends Model
{
...
public function getInviteeNameAttribute() {
return $this->first_name . ' ' . $this->last_name;
}
}
...then get that attribute from invitee:
$invitees[0]->invitee_name
See https://laravel.com/docs/7.x/eloquent-mutators#defining-an-accessor

Laravel Eloquent 'belongs to' relationship books and its category

I'm trying to print all books' name in 'books' table and its category associated. But it doesn't show any content nor error messages.
Model::Book.php
class Book extends Eloquent{
protected $table ='books';
public function bookCat()
{
return $this->belongsTo('BookCategory');
}
}
Model::BookCategory.php
class BookCategory extends Eloquent{
protected $table ='book_categories';
}
Controller::route.php
Route::get('/', function()
{
$books = Book::all();
return View::make('books')
->with('books', $books);
});
View::books.blade.php
#foreach ($books as $book)
<li>{{ $book->book_name }}</li>
- <small>{{ $book->bookCat }}</small>
#endforeach
Table::books
(int)id, (string)book_name, (int)category_id
Table::book_categories
(int)id, (string)category
Add the relationship to BookCategory.
class BookCategory extends Eloquent{
protected $table ='book_categories';
public function books() {
return $this->hasMany('Book');
}
}
Your local key doesn't match the model names, either, so you would need to specify that in the relation:
class Book extends Eloquent{
protected $table ='books';
public function bookCat()
{
return $this->belongsTo('BookCategory', 'category_id');
}
}
You may also want to eager-load the categories in your controller, as your query is for the books:
$books = Book::with('bookCat')->get();

How do display a variable from a databse with through Relational Models?

I have a list of books and a list of authors. I made the Model relations, so that my Book Model says, that books->belongTo('Author') and my Author Model says, that authors->hasMany('Book').
So normally I could access the a variable through this:
$books = Book::all();
And then in the view:
#foreach($books as $book)
<div>{{$book->id}}</div>
<div>{{$book->title}}</div>
<div>{{$book->authors->firstname}}</div>
#endforeach
But this does not work. I get the error message: Trying to get property of non-object
So here are my files:
My Models:
Book.php
class Book extends \Eloquent {
protected $guarded = [];
public function religions()
{
return $this->belongsTo('Religion');
}
public function branches()
{
return $this->belongsTo('Branch');
}
public function authors()
{
return $this->belongsTo('Author');
}
public function quotes()
{
return $this->hasMany('Quote');
}
public function chapters()
{
return $this->hasMany('Chapter');
}
}
Author.php
class Author extends \Eloquent {
protected $guarded = [];
public function books()
{
return $this->hasMany('Book');
}
public function quotes()
{
return $this->hasMany('Quote');
}
public function branches()
{
return $this->belongsTo('Branch');
}
public function religions()
{
return $this->belongsTo('Religion');
}
}
Then come my controller:
ReligionBranchBookController
class ReligionBranchBookController extends \BaseController {
/**
* Display a listing of the resource.
*
* #return Response
*/
public function index($religionId, $branchId)
{
//
// $books = Book::where('religion_id', $religionId)->where('branch_id', $branchId)->get();
$books = Book::all();
$authors = Author::all();
// dd($books->toArray());
return View::make('books.index')
->with('religionId', $religionId)
->with('branchId', $branchId)
->with('books', $books)
->with('authors', $authors);
}
}
My Views:
index.blade.php
#extends('layout.main')
#section('content')
<h1>Books List!!</h1>
<table>
<tr>
<th>ID</th>
<th>Title</th>
<th>Author</th>
</tr>
#foreach($books as $book)
<tr>
<td>{{$book->id}}</td>
<td>{{$book->title}}</td>
<td>{{$book->authors->firstname}}</td>
</tr>
#endforeach
</table>
#stop
I know that it should normally work, I rebuild it with only books and authors, and it works fine there.
So, does anyone have an idea, where I am going wrong?
Thanks,
George
In your Book model change the authors method to author like this:
public function author()
{
return $this->belongsTo('Author');
}
Because, one book belongs to one author according to your relationship and when you call authors the belongsTo->getResults() get called and runs the wrong query so authors get null and you get the error. Things to remember:
For hasOne and belongsTo relationship use singular form of relationship method, i.e, author not authors.
hasOne or belongsTo returns a single model object.
For hasMany and belongsToMany relationship use plural form of relationship method, i.e, authors not author.
hasMany and belongsToMany returns a collection of model objects.

Retrieving relationships of relationships using Eloquent in Laravel

I have a database with the following tables and relationships:
Advert 1-1 Car m-1 Model m-1 Brand
If I want to retrieve an Advert, I can simply use:
Advert::find(1);
If I want the details of the car, I could use:
Advert::find(1)->with('Car');
However, if I also want the detail of the Model (following the relationship with Car), what would the syntax be, the following doesn't work:
Advert::find(1)->with('Car')->with('Model');
Many thanks
It's in the official documentation under "Eager Loading"
Multiple relationships:
$books = Book::with('author', 'publisher')->get();
Nested relationships:
$books = Book::with('author.contacts')->get();
So for you:
Advert::with('Car.Model')->find(1);
First you need to create your relations,
<?php
class Advert extends Eloquent {
public function car()
{
return $this->belongsTo('Car');
}
}
class Car extends Eloquent {
public function model()
{
return $this->belongsTo('Model');
}
}
class Model extends Eloquent {
public function brand()
{
return $this->belongsTo('Brand');
}
public function cars()
{
return $this->hasMany('Car');
}
}
class Brand extends Eloquent {
public function models()
{
return $this->hasMany('Model');
}
}
Then you just have to access this way:
echo Advert::find(1)->car->model->brand->name;
But your table fields shoud be, because Laravel guess them that way:
id (for all tables)
car_id
model_id
brand_id
Or you'll have to specify them in the relationship.
Suppose you have 3 models region,city,hotels and to get all hotels with city and region then
Define relationship in them as follows:-
Hotel.php
class Hotel extends Model {
public function cities(){
return $this->hasMany(City::class);
}
public function city(){
return $this->belongsTo('App\City','city_id');
}
}
City.php
class City extends Model {
public function hotels(){
return $this->hasMany(Hotel::class);
}
public function regions(){
return $this->belongsTo('App\Region','region_id');
}
}
Region.php
class Region extends Model
{
public function cities(){
return $this->hasMany('App\City');
}
public function country(){
return $this->belongsTo('App\Country','country_id');
}
}
HotelController.php
public function getAllHotels(){
// get all hotes with city and region
$hotels = Hotel::with('city.regions')->get()->toArray();
}
will adding the relation function just ask for the relation needed
public function Car()
{
return $this->belongsTo(Car::class, 'car_id')->with('Model');
}
but if you want a nested relation just use the period in the with
Advert::with('Car.Model')->find(1);
but for multi-relation use the array
Advert::with('Car','Model')->find(1);

Get value from view

I have two table User & Article the relationship between tables are
Model:
class Article extends Eloquent {
public static $table = 'article';
public function User()
{
return $this->has_one('user', 'id');
}
and
class User extends Eloquent {
public static $table = 'user';
public function Article()
{
return $this->belongs_to('article', 'id_user');
}
I want to get name value from User directly on Article view but don't works with error
Trying to get property of non-object
My Controller:
public function action_index()
{
$Article = Article::order_by('id')->paginate(10);
return View::make('article.index')->with('$articles', $Article);
}
My View:
#foreach ($articles->results as $Arti)
<tr>
<td>{{$Arti->id}}</td>
<td>{{$Arti->tag}}</td>
<td>{{$Arti->user->name }}</td> <------ ERROR
<td>{{$Arti->content}}</td>
<td>{{$Arti->date}}</td>
<td>
Have a look at the below, a few things are different to yours...
Article belongs_to User (not has_one)
User has_many Article (not belongs_to)
Your relationships should be named in lowercase, plural for has_many (i.e. articles or user)
Your relationship subjects should be class names (i.e. Article or User)
Foreign keys should be name relationship_id, i.e. user_id
Add ::with() to your query to eager load relationships
When you paginate you need to access ->results in your view
class Article extends Eloquent {
// 3: lowercase 'user'
public function user()
{
// 1: Article belongs to User
// 4: class name 'User'
// 5: Foreign key on article table is user_id
return $this->belongs_to('User');
}
}
// models/user.php
class User extends Eloquent {
// 3: lowercase plural 'articles'
public function articles()
{
// 2: User has many Articles
// 4: class name 'Article'
return $this->has_many('Article');
}
}
// controllers/articles.php
class Article_Controller extends Base_Controller {
public $restful = true;
public function get_index()
{
// 6: Eager load the user relationship, ::with('user')
$articles = Article::with('user')->order_by('id')->paginate(10);
return View::make('articles.index', compact('articles'));
}
}
// views/articles/index.blade.php
// 7: access $articles->results from the paginator
#foreach ($articles->results as $article)
<h1>{{ $article->title }}</h1>
<p>By {{ $article->user->name }}</p>
#endforeach
{{ $articles->links() }}

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