Eloquent group by product, ordering differently based on product - laravel-5

Question

I currently have the following set up:
Category, SubCategory, Business, Enhancement & Product models.
A Category has many SubCategorys
A SubCategory has many Businesss
A Business may have one Enhancement
A Enhancement must have one Product
A product could be an enhanced listing, a premium listing, or additional features.
If the business has brought either an enhanced or premium listing, it is recorded in the enhancement table.
So, product#1 = Premium Listing. Product#2 = Enhanced listing.
What I am wanting is to return all the businesses for a chosen SubCategory, grouping by the product that the enhancement is attached to. If the business has an enhancement, I'm wanting to randomise the order. If the business does not have a product, I'm wanting to order by name in ASC order.
So the result I'm expecting is to have a complete list of all businesses, with those with a Premium Listing, listed first in a random order. Then all businesses with an enhanced listing in a random order. Then all the other businesses that have no enhancement, in alphabetical order.
I currently have all the businesses listed in name order with the following code:
SubCategory::where('slug', $subCategory)->where('category_id', $category->id)
->with(['businesses' => function($query) {
$query->orderBy('name', 'ASC');
}])->firstOrFail();
Category model:
class Category extends Model
{
public function subCategories()
{
return $this->hasMany('\App\SubCategory');
}
}
SubCategory model:
class SubCategory extends Model
{
public function businesses()
{
return $this->hasMany('\App\Business');
}
public function category()
{
return $this->belongsTo('\App\Category');
}
}
Business model:
class Business extends Model
{
public function subCategory()
{
return $this->belongsTo('\App\SubCategory');
}
public function enhancements()
{
return $this->hasMany('\App\Enhancement');
}
}
Enhancement model:
class Enhancement extends Model
{
public function business()
{
return $this->belongsTo('\App\Business');
}
public function product()
{
return $this->belongsTo('\App\Product');
}
}
Product model:
class Product extends Model { }
Migrations:
Schema::create('categories', function (Blueprint $table) {
$table->increments('id');
$table->string('name')->unique();
$table->string('slug')->unique();
$table->string('featured_image');
$table->text('description');
$table->unsignedInteger('sort_order')->nullable();
$table->timestamps();
$table->softDeletes();
});
Schema::create('sub_categories', function (Blueprint $table) {
$table->increments('id');
$table->unsignedInteger('category_id');
$table->string('name')->unique();
$table->string('slug')->unique();
$table->string('featured_image');
$table->text('description')->nullable();
$table->unsignedInteger('sort_order')->nullable();
$table->timestamps();
$table->softDeletes();
$table->foreign('category_id')->references('id')->on('categories');
});
Schema::create('businesses', function (Blueprint $table) {
$table->increments('id');
$table->unsignedInteger('resort_id');
$table->unsignedInteger('sub_category_id');
$table->string('name');
$table->string('slug')->unique();
$table->string('logo')->nullable();
$table->text('description');
$table->text('content')->nullable();
$table->string('county')->nullable();
$table->string('postcode')->nullable();
$table->timestamps();
$table->foreign('resort_id')->references('id')->on('resorts');
$table->foreign('sub_category_id')->references('id')->on('sub_categories');
});
Schema::create('enhancements', function (Blueprint $table) {
$table->increments('id');
$table->unsignedInteger('business_id');
$table->unsignedInteger('product_id');
$table->dateTime('from_date');
$table->dateTime('to_date');
$table->timestamps();
$table->softDeletes();
$table->foreign('business_id')->references('id')->on('businesses');
$table->foreign('product_id')->references('id')->on('products');
});
Schema::create('products', function (Blueprint $table) {
$table->increments('id');
$table->string('name');
$table->string('slug')->unique();
$table->string('image');
$table->text('description');
$table->float('yearly_price');
$table->float('monthly_price');
$table->timestamps();
});

Answer 1

This should work for you:
SubCategory::where('slug', $subCategory)
->where('category_id', $category->id)
->with(['businesses' => function($query) {
$query->select('businesses.*')
->leftJoin('enhancements', function($join) {
$join->on('enhancements.business_id', '=', 'businesses.id')
->join('products', 'products.id', 'enhancements.product_id');
})
->orderByRaw('FIELD(products.slug, ?, ?) DESC', ['enhanced-listing', 'premium-listing'])
->orderByRaw('CASE WHEN products.slug IS NOT NULL THEN RAND() ELSE businesses.name END');
}])->firstOrFail();