Self-relationship in Group table with Laravel and Eloquent?

Auto Relationship Laravel

  

1) the migration corresponding to this table?

To create the file ( the blank template ) in console do:

php artisan make:migration Grupo

Configuring:

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class Grupo extends Migration
{
    public function up()
    {
        Schema::create('grupo', function (Blueprint $table) 
        {    
            $table->increments('id');    
            $table->string('description', 50);    
            $table->integer("grupoid", false, true)
                ->nullable();    
            $table->index("grupoid");    
            $table->foreign("grupoid")
                ->references('id')
                ->on('grupo');                
        });
    }
    public function down()
    {
        Schema::drop('grupo');
    }
}

Generate Table:

php artisan migrate

  

2) creating the Eloquent model with the relationship?

To create the file ( the blank template ) in console do:

php artisan make:model Grupo

Configuring:

namespace App\Models;    
use Illuminate\Database\Eloquent\Model;

class Grupo extends Model
{
    protected $primaryKey = "id";
    protected $fillable = array('description','grupoid');
    protected $table = "grupo";
    public $timestamps = false;

    //relacionamento (auto-relacionamento) item 4 
    public function grupos()
    {
        return $this->hasMany(Grupo::class, 'grupoid', 'id');
    }

    // um técnica do item 3
    public function isFather()
    {
        return is_null($this->attributes['grupoid']);
    }

    // aqui seria o item 3  
    protected $appends = ['is_father'];
    public function getIsFatherAttribute()
    {
        return is_null($this->attributes['grupoid']);
    }
}

  

3) How would you know if a given id is Father, any technique?

In the 2) item, two techniques were created:

• One would be to create a method and compare if the grupoid is null (is_null) and the isFather() method was created:

public function isFather()
{
    return is_null($this->attributes['grupoid']);
}

• But with method only it does not come out in the results of Array or Json , so we'll create a appends in that Model Grupo :

protected $appends = ['is_father'];
public function getIsFatherAttribute()
{
    return is_null($this->attributes['grupoid']);
}

resulting in the format JSON :

{"id":4,"description":"Grupo 2","grupoid":null,"is_father":true,"grupos":[]}

  

4) if id is Parent how to load children into relationships?

Simply with the command with :

$grupo = App\Models\Grupo();
$grupo->with('grupos')->find(4);