问公共模型的多个1到1关系

EN

name       type   nullable
------------------------------
id         int    no
name       text   no
human_id   int    yes 
alien_id   int    yes

class Cookie extends Eloquent {

    public function human()
    {
        return $this->belongsTo('Human', 'human_id');
    }

    public function alien()
    {
        return $this->belongsTo('Alien', 'alien_id');
    }

}

class Alien extends Eloquent {

    public function cookie()
    {
        return $this->hasOne('Cookie', 'alien_id');
    }

}

class Human extends Eloquent {

    public function cookie()
    {
        return $this->hasOne('Cookie', 'human_id');
    }

}

$human = Human::find(1);

echo $human->cookie->name;

$cookie = Cookie::find(1);

if ($cookie->human) echo $cookie->human->name;
if ($cookie->alien) echo $cookie->alien->name;