How do I get all children that fall under a parent in eloquent?

Question

In my database, I have a Categories table. Categories can have parent categories, making it a recursive relationship

I also have a products table. Each product falls

Answer 1

This way works very good:

class One extends Model {
    public function children()
    {
        return $this->hasMany(self::class, 'parent_id');
    }

    public function grandchildren()
    {
        return $this->children()->with('grandchildren');
    }
}

Answer 2

After hoping to find an answer that uses Laravel nicely, I ended up giving up and just writing the code to do what I wanted myself, and it ended up smaller than I anticipated.

public function all_products()
{
    $products = [];
    $categories = [$this];
    while(count($categories) > 0){
        $nextCategories = [];
        foreach ($categories as $category) {
            $products = array_merge($products, $category->products->all());
            $nextCategories = array_merge($nextCategories, $category->children->all());
        }
        $categories = $nextCategories;
    }
    return new Collection($products); //Illuminate\Database\Eloquent\Collection
}

Answer 3

Suppose your Model name is Category

Create a function on Category model

public function children() { return $this->hasMany('App\Category', 'parent_id', 'id'); }

Using above method on your controller

$categories = Category::with('children')->where('parent_id',0)->get();

Answer 4

you better use nested sets models. you should use this data structure due to get fastest way to query in mysql with a simple way. with just a parent_id attribute,you don't know how deep your tree is and this make problem in knowing how many join you need. I offer you this excellent article. managing-hierarchical-data-in-mysql

for those who use laravel framework, I prefer to suggest this amazing package:Baum

Answer 5

Say $category_id = Category->id and you want a collection of products as children of that category, I would try:

$products = App\Product::with(['SubSubCategory.SubCategory.Category'=>function($query) use ($category_id) {$query->where('id', $category_id);}])->get();

To be able to do so. You will need your 'one to many' inverse relationships to be as such:

//App\SubCategory

public function Category(){return $this->belongsTo('App\Category');}

//App\SubSubCategory

public function Sub_Category(){return $this->belongsTo('App\SubCategory');}

//App\Product

public function SubSubCategory(){return $this->belongsTo('App\SubSubCategory');}

Good luck.

Answer 6

please try the below Has Many Through relation and post the result

class Category extends Model
{
    public function products()
    {
        return $this->hasManyThrough(
            'App\Product', 'App\Category',
            'parent_id', 'catergory_id', 'id'
        );
    }
}

Then you can use $category->products; to find your products