Laravel eloquent with categories - laravel

Question

I have a question about eloquent in laravel.
DB tables
categories: id root_id name
products id name etc..
product_categories id product_id category_id
So it might be CategoryA which has a child CategoryB and CategoryB by itself has a child CategoryC.
When I click in CategoryA I want to find all products that are part of CategoryA, CategoryB, CategoryC
Category Model
public function cats()
{
return $this->hasMany(Category::class);
}
public function childrenCategories()
{
return $this->hasMany(Category::class)->with('cats');
}
Product Model
public function categories()
{
return $this->belongsToMany(Category::class);
}
Controller
//firsty I get all id of all categories, subcategories of all levels.
$categories = Category::where('category_id',$category_id)->with('childrenCategories')->get();
$all_cat_array=array();$all_prod=array();
foreach ($categories as $category)
{
foreach ($category->childrenCategories as $childCategory) {
array_push($all_cat_array, $childCategory->id);
}
array_push($all_cat_array,$category->id);
}
//then i get all id of products
foreach ($all_cat_array as $cat)
{
if(CategoryProduct::where('category_id',$cat)->exists()) {
$prod=CategoryProduct::where('category_id',$cat)->pluck('product_id');
array_push($all_prod,$prod );
}
}
But I don't want to use of all these foreach, since I want to optimise the code.
What can I do to make it simplier ???

Answer 1

For more information please read Laravel Docs
DATABASE
Category A database
Schema::create('category_as', function (Blueprint $table) {
$table->bigIncrements('id');
$table->unsignedBigInteger('product_id');
...
$table->timestamps();
$table->foreign('product_id')->references('id')->on('products')->onDelete('cascade');
});
Category B database
Schema::create('category_bs', function (Blueprint $table) {
$table->bigIncrements('id');
$table->unsignedBigInteger('category_a_id');
...
$table->timestamps();
$table->foreign('category_a_id')->references('id')->on('category_as')->onDelete('cascade');
});
MODEL
Products model
public function categories_a() {
return $this->hasmany(Category_a::class);
}
Category A model
public function categories_b() {
return $this->hasmany(Category_b::class);
}
public function product() {
return $this->belongsTo(Product::class);
}
Category B model
public function category_a() {
return $this->belongsTo(Category_a::class);
}
public function clients() {
return $this->hasManyThrough(Client::class, Code::class);
}
CONTROLLER
public function index() {
$products = Product::all();
$query = $products->categories_a->categories_b;
dd($query);
}
EDITED
DATABASE
Category A database
Schema::create('categories', function (Blueprint $table) {
$table->bigIncrements('id');
$table->unsignedBigInteger('product_id');
...
$table->timestamps();
$table->foreign('product_id')->references('id')->on('products')->onDelete('cascade');
});
MODEL
Products model
public function categories() {
return $this->hasmany(Category::class);
}
Category model
public function product() {
return $this->belongsTo(Product::class);
}
CONTROLLER
public function index() {
$products = Product::all();
$query = $products->categories;
dd($query);
}

Answer 2

I recommend you to use nested set structure in Category model.
It is well implemented in this package https://github.com/lazychaser/laravel-nestedset.
You could get products of category and all it's descendants (with unlimited nesting) with 2 queries.
If Category belongsToMany Product:
$categoryIds = Category::descendantsAndSelf($categoryId)->pluck('id');
$products = Product::whereHas('categories', function ($query) use ($categoryIds) {
$query->whereIn('categories.id', $categoryIds);
});
If Category hasMany Product
$categoryIds = Category::descendantsAndSelf($categoryId)->pluck('id');
$products = Product::whereIn('category_id', $categoryIds);