hasMany relation not working in laravel - laravel

Question

My cart model has:
public function product() {
return $this->hasMany('App\Product');
}
My Product Model has:
public function cart() {
return $this->belongsTo('App\Cart');
}
My database looks like:
Cart Table:
Product Table:
My cart migration contains:
$table->integer('product_id')->unsigned();
$table->foreign('product_id')->references('id')->on('products')->onDelete('cascade');
My controller contains:
public function index()
{
if(Auth::check())
{
$user = Auth::user();
$cart = Cart::where('user_id',$user->id)->get();
return view('products.cart')->withCart($cart);
}
else {
return view('products.cart');
}
}
It checks if user is logged in then it get details of all cart where user id matches with current user. This is working.
But when I go to product.cart page I try:
#foreach($cart->product as $p)
{{dd($p->name)}}
#endforeach
I get error:
Undefined property: Illuminate\Database\Eloquent\Collection::$product (View: D:\wamp64\www\ecommerce\resources\views\products\cart.blade.php)
Can you tell me how to get value from products table with this relationship.
Thanks!
Edit:
After trying different method I got:
Cart Model:
public function product() {
return $this->hasMany('App\Product','id','product_id');
}
Cart Controller:
public function index()
{
if(Auth::check())
{
$user = Auth::user();
$cart = Cart::where('user_id',$user->id)->first();
return view('products.cart')->withCart($cart);
}
else {
return view('products.cart');
}
}
Now I am able to get the first product that matches with id.
Is there a way to get all product that matches

Answer 1

You use $...->get() returns collection. Use first() instead.
$cart = Cart::where('user_id',$user->id)->first();
if($cart) {
return view('products.cart')->withCart($cart);
} else {
abort(404);
}

Answer 2

Go to User's model:
public function products()
{
return $this->hasManyThrough('App\Product', 'App\Cart');
}
Now, in your controller you'll fetch the logged user's cart. And pass it to the view. e.g
return view('cart.show', ['cart' => Auth::user()->cart]);
Then your foreach will work like expected.
PS: You may have to specify ids on the hasManyThrough relation if you're not using the convention naming for database tables. i.e Model singular (Product) to pluralized tables (products).

Answer 3

Try out the following code.
In your Cart Model
public function product(){
return $this->belongsTo('App\Product','id','product_id')
}
In your Controller
$cart = Cart::where('user_id',$user->id)->first();

Answer 4

In your Cart model you need to specify relation for products:
public function products(){
//return $this->hasMany('App\Product'); should be changed to
return return $this->belongsToMany('App\Product','carts_products', 'cart_id', 'product_id'); // see link to tutorial below.
}
With this relation you can enable lazy loading of products when you get Cart object for user to achieve this in your controller you need:
public function index()
{
if(Auth::check())
{
$user = Auth::user();
$cart = Cart::with('products')->where('user_id',$user->id)->first();
//we get cart via first() as we need single instance of cart not an array of carts,
//even there's only one cart per user get() will return an array of one item
// with('products') lazyloads linked products to cart as you get cart instance
return view('products.cart')->with('cart',$cart);
}
else {
return view('products.cart');
}
}
Later in your view you'll be able to iterate over lazy loaded products array like:
#foreach($cart->products as $p)
{{dd($p->name)}}
#endforeach
Think of creating relations between models in terms of how you'll access them in future, most of the time you don't need to overspecify all relations between objects, as only some of them you'll realy use in code.
Hope it'll help you.
EDIT
change relation type to belongsToMany and it should work, as your Cart has many Products. You still need to get one single Cart instance with first() method byt related Products will be loaded as you need.
Important:
Look at this tutorial https://scotch.io/tutorials/a-guide-to-using-eloquent-orm-in-laravel as you need to change your database schema to achieve this. Currently your schema allows you to have only one product per cart. Look into this example where they create picnics to bears table bears_picnics - in your case you'll have products to carts table carts_products walk through tutorial in you case cart is bear and picnics are products.
Example carts_products schema:
Schema::create('carts_products', function(Blueprint $table)
{
$table->increments('id');
$table->integer('cart_id'); // the id of cart
$table->integer('product_id'); // the id of product in cart
$table->timestamps();
});
remove product_id field from you cart schema as it's useless in such case. if you need cascade deletion specify it on carts_products table.
Happy codding! Thank you for a good question:) making us to make a research deeper.