class Company extends Model { public function okruga() { return $this->hasMany('App\Okrug'); } public function results() { return $this->hasMany('App\Result'); } } class Okrug extends Model { public function cities() { return $this->belongsToMany('App\City'); } public function company() { return $this->belongsTo('App\Company'); } } class City extends Model { public function okruga() { return $this->belongsToMany('App\Okrug'); } } class Result extends Model { public function company() { return $this->belongsTo('App\Company'); } public function city() { return $this->belongsTo('App\City'); } }