How can i make three tables relationships in laravel 5.4 - php

Question

I want to create dynamice mega menu but i'm getting error when i'm making tables relationship. Please let me know how can i make relationship.
Table structure Below:-
1) categories
id integer
category varchar
2) subcategories
id integer
subcategory varchar
category_id integer
3) parentcategories
id integer
parentname varchar
subcategory_id integer
Models
Categories.php
protected $table = "categories";
public function sub(){
return $this->hasManyThrough(Subcategories::class,Parentcategories::class,'subcategory_id','category_id');
}
Subcategories.php
protected $table = "subcategories";
public function category()
{
return $this->belongsTo('App\Categories');
}
Parentcategories.php
protected $table = "parentcategories";
public function subcategory()
{
return $this->belongsTo('App\Subcategories');
}
PagesController.php
public function index(){
$categories = Categories::all();
return view('pages.home')->with('categories',$categories);
}
blade template
#foreach($categories as $category)
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">
{{ $category->category }} <i class="fa fa-chevron-down"
aria-hidden="true"></i>
</a>
<ul class="mega-menu dropdown-menu">
#foreach($category->sub->take(20) as $subcategory)
<li class="col-sm-3">
<h5>{{$subcategory->subcategory}} <i class="fa fa-caret-right" aria-hidden="true"></i></h5>
<ul class="mega-list">
<li>parent categories comes here</li>
</ul>
</li>
#endforeach
</ul>
</li>
#endforeach
Thanks

Answer 1

As I can see your table are hierarchy is in simillar fashion, I guess this can be done with single table. Create a table named categories and follow the below table structure:
Now create a model Category.php: something like this:
<?php
class Category extends Eloquent {
/**
* The database table used by the model.
*
* #var string
*/
protected $table = 'categories';
public function parent() {
return $this->hasOne('category', 'id', 'parent_id');
}
public function children() {
return $this->hasMany('category', 'parent_id', 'id');
}
public static function tree() {
return static::with(implode('.', array_fill(0, 4, 'children')))->where('parent_id', '=', NULL)->get();
}
}
Now in your controller suppose HomeController.php write:
<?php
class HomeController extends BaseController {
protected $layout = "layouts.main";
public function showWelcome()
{
$items = Category::tree();
$this->layout->content = View::make('layouts.home.index')->withItems($items);
}
}
And in views suppose index.blade.php you can simply pass like this:
<ul>
#foreach($items as $item)
<li>{{ $item->title }}
#foreach($item['children'] as $child)
<li>{{ $child->title }}</li>
#endforeach
</li>
#endforeach
</ul>
This works for n-number for hierarchy, more efficient and a single table categories, hope this helps