Problem with Required field and Request after using relationship with ID

After making a CRUD with relationship, and making it required. 
img: http://imgur.com/SxwawHm

This is the generated Request file, the id field show only a -

```
    public function rules()
    {
        return [
            'title' => 'required', 
            '-' => 'required', 

        ];
    }
```

Am i making the CRUD wrong, or is there an error?
