Relationship between various tables in Eloquent

Question

I am trying to create the models in Lumen based on my current database for a virtual store, but I am having difficulties to configure the relationships between them.
So far I have the following Models:

*Product

<?php
namespace App\Models;

use Illuminate\Database\Eloquent\Model;

final class Product extends Model
{
    /**
     * The database table used by the model.
     *
     * @var string
     */
    protected $table = 'products';

    public function productColor()
    {
        return $this->hasMany('ProductColor', 'id_product');
    }

}

*Productcolor

<?php
namespace App\Models;

use Illuminate\Database\Eloquent\Model;

final class ProductColor extends Model
{
    /**
     * The database table used by the model.
     *
     * @var string
     */
    protected $table = 'product_colors';

    public function sizeByProductColor()
    {
        return $this->hasMany('SizeByProductColor', 'id_product_color');
    }

}

*Sizebyproductcolor

<?php
namespace App\Models;

use Illuminate\Database\Eloquent\Model;

final class SizeByProductColor extends Model
{
    /**
     * The database table used by the model.
     *
     * @var string
     */
    protected $table = 'sizes_by_product_color';

    public function size()
    {
        return $this->hasMany('Size','id_size');
    }

    public function productColor()
    {
        return $this->belongsTo('productColor', 'id_product_color');
    }

}

*Size

<?php
namespace App\Models;

use Illuminate\Database\Eloquent\Model;

final class Size extends Model
{
    /**
     * The database table used by the model.
     *
     * @var string
     */
    protected $table = 'sizes';

    public function productColor()
    {
        return $this->belongsTo('SizeByProductColor');
    }
}

My problem is that I’ve never worked with so many relationships and now this is giving me a lot of headache.
So I’m following the right path as the Models?
Note: Products have Colors and each product color has various shoe sizes and stock. Example: If I needed to get the sizes for certain color I would use the following SQL:

SELECT * FROM sizes as s
LEFT JOIN product_colors as pc ON pc.id_color = 6 
INNER JOIN sizes_by_product_color as sbpc ON s.id = sbpc.id_size AND pc.id = sbpc.id_product_color

How can I make this query in Controller?

Answer 1

in the product model

public function cores()
{
    return $this->hasMany('Cormodel');
}

//produto->cores me retorna todo as cores do produto

in the color model

public function produto()
{
    return $this->belongsTo('Produtomodel');
}

public function tamanhos()
{
    return $this->hasMany('Tamanhomodel');
}

//cor->tamanhos me retorna todos os tamanhos desse cor
//cores->produto me retorna o produto daquela cor

in size model

    public function cor()
    {
        return $this->belongsTo('Cormodel');
    }

    public function cores()
    {
        return $this->hasMany('Cormodel');
    }

//tamanho->cor me retorna o tamanho daquela cor
//tamanho->cores retorna as cores desse tamanho

and so on