belongsToMany(City::class, 'cities_companies', 'company_id', 'city_id'); } public function categories(): HasMany { return $this->hasMany(Category::class); } public static function isExist(int $id): bool { $count = Company::where('id', $id)->count(); return $count != 0; } public static function isExistByName(string $name): bool { $count = Company::where('name', $name)->count(); return $count != 0; } public static function isNameValid(string $name): bool { return $name != ''; } }