Showing categories and lowest price with Laravel

Question

Trying to show all categories from database and based of products in category to show lowest price. So what I have so far is: Model Categories.php

class Categories extends Eloquent {
    protected $table = 'category';
    protected $primaryKey = 'category_id';

    public $timestamps = false;

    public function products()
    {
        return $this->hasMany('Product', 'category_id');
        //return $this->belongsToMany('Product', 'category_id');
    }
}

This is Product.php Model

class Product extends Eloquent {
     protected $table = 'products';
     protected $primaryKey = 'product_id';

     public function categories()
     {
         return $this->hasMany('Categories', 'category_id');
         //return $this->belongsToMany('Categories', 'category_id');
     }

     public $timestamps = false;
}

And this is HomeController.php which load index.blade.php view

class HomeController extends BaseController {

   public function index()
   {                           
      $products = Product::where('category_id', '!=', 1)
          ->with('category')
          ->min('price')
          ->get();          

            return View::make('site.index', [
                'categories' => $categories
            ]); 
   }
}

Right now when I load the page I get this error

production.ERROR: exception 'Symfony\Component\Debug\Exception\FatalErrorException' with message 'Call to a member function get() on a non-object' in ....

What is wrong here and how I can display categories and lowest price of each category?

Update: This is how is look now

Categories.php model

class Categories extends Eloquent {
    protected $table = 'category';
    protected $primaryKey = 'category_id';

    public $timestamps = false;

    public function products()
    {
        return $this->hasMany('Product', 'category_id');
    } 

    public function lowestProduct() {
        return $this->products()->selectRaw('*, max(price) as aggregate')
          ->groupBy('products.product_id')->orderBy('aggregate');
    }
}

HomeController.php

public function index()
{

    $categories = Categories::with('lowestProduct')->get();         
     //$categories = Categories::paginate(15);
            return View::make('site.index', [
                'categories' => $categories
    ]); 
}

Answer 1

In your view you probably have a foreach statement. Put this there:

$category->products()->min('price');

It is the lowest product's price in this category.