Adding subcategories to laravel 5.4

Question

I have categories table in my application and it works just fine but i wonder how to get subcategories for that as well?

currently what I have is:

Category Model

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Category extends Model
{

  protected $fillable = ['name'];

  public function ads(){
     return $this->hasMany(Ad::class);
  }

}

Category Migration:

public function up()
    {
        Schema::create('categories', function (Blueprint $table) {
            $table->increments('id');
            $table->string('name');
            $table->string('slug')->unique();
            $table->timestamps();
        });
    }

My Post Model:

public function category(){
       return $this->belongsTo(Category::class);
    }

PS: I know I have to make new table and call for foreign key of category_id for subcategories but what makes me confuse is the relationships and also how to select them in front-end so category and subcategories all shows in one drop down to user (like WP)?

Answer 1

i really don't understand well what you're trying to do .. but if you're trying to add both categories and subcategories in one dropdown i assume this is what you wanted:

let's say you already have done the relationship .. in your controller

$categories = Category::with('sub_categories')->get();
return view('page',compact('categories'));

now we got all the categories and it's corresponding sub-categories .. in your blade all you have to do is

<select name="categories">
@foreach($categories as $categ)
    <optgroup label="{{ $categ->name }}">
        @foreach($categ->sub_categories as $sub)
            <option value="{{ $sub->id }}">{{ $sub->name }}</option>
        @endforeach
    </optgroup>
@endforeach
</select>

and that would give you an output like

 <select> <optgroup label="Fruits"> <option value="1">Apple</option> <option value="2">Banana</option> </optgroup> <optgroup label="Vegetables"> <option value="3">Beans</option> <option value="4">Cabbage</option> </optgroup> </select> 

EDIT

relationship is easy as understanding english .. actually you've done it already in your category ads ..

CATEGORY MODEL

public function ads()
{
    return $this->hasMany('App\Ad');
    // return $this->hasMany('App\Ad','theforeignfieldtocomparetomyprimarykey')
}

hasMany - this means Ad model has category_id in it's database table as field ..

in your AD MODEL

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

belongsTo - since the function name is category it will look up on his fields for category_id and match it to the primary key of model category

so basically what you have to do is first make models with migrations like:

CATEGORY

• id
• name

SUB CATEGORY

• id
• category_id
• name

then in your model you should have a script as exampled above ..