Laravel 搜索关系

我有两个相关的型号.我试图在产品中进行搜索，并且只显示实际的搜索结果，而不是找到该产品所在类别的所有产品.我不想搜索任何类别，因为无论搜索什么，无论找到什么，这些类别都会一直显示出来.

Example. I have the following categories:

- Food
- Drinks
- Candy

My "Food" category has the following products:

- Strawberry
- Apple
- Banana

My "Drinks" category has the following products:

- Banana Cocktail
- Beer
- Cola

My "Candy" category has the following products:

- Strawberry Lollipop
- Chocolate Bar
- Banana Ice Cream

So, what I WANT to achieve is the following. I do a search for a product called "Banana". What I WANT to be displayed is:

Category Food
- Product Banana

Category Drinks
- Product Banana Cocktail

Category Candy
- Product Banana Ice Cream

But my issue is, with my code, if I perform a search for "Banana", it displays the category in which banana is found, and it returns and displays ALL products in that category instead of ONLY the products that I searched for. How can I achieve it so only the products that was searched for are displayed?

类别型号:

class Categories extends Eloquent {

    public function products()
    {
        return $this->hasMany('Products');
    } 
}

产品型号:

class Products extends Eloquent {

    public function categories()
    {
        return $this->belongsTo('Categories');
    }
}

我的控制器:

    $searchString       = Input::get('search');

    if($searchString)
    {
        $categories = Categories::with('products')->orderBy($order, $by)->whereHas('products', function ($query) use ($searchString){
            $query->where('name', 'like', '%'.$searchString.'%');
        })->get();
    }
    else {
        $categories     = Categories::with('products')->orderBy($order, $by)->get();
    }

我的观点是:

@foreach($categories as $category)
    {{ $category->name }} // Show the category name

    @foreach($category->products as $product)
    {{ $product->name }} // Show all products in that category

    @endforeach
@endforeach