Horux_back/app/Models/Taxpayer.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Relations\BelongsToMany;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\Model;

class Taxpayer extends Model
{
    use HasFactory;

    protected $fillable = [
        'rfc_id'
    ];

    public function rfc(): BelongsTo
    {
        return $this->belongsTo(Rfc::class);
    }

    public function economicActivities(): BelongsToMany
    {
        return $this->belongsToMany(EconomicActivity::class);
    }

    public function taxRegimes(): BelongsToMany
    {
        return $this->belongsToMany(TaxRegime::class);
    }

    public function risks(): BelongsToMany
    {
        return $this->belongsToMany(Risks::class);
    }

    public function salesRevenues(): HasMany
    {
        return $this->hasMany(SalesRevenue::class);
    }

    public function expenditures(): HasMany
    {
        return $this->hasMany(Expenditure::class);
    }
}