Doesn't work with many models

[eiko03]

I have tried it with my project of 9 models. All have relations between them. It just shows table and keys, no arrow to define relation
for example..
One model..

    public function students_s(){
        return $this->hasMany('Student');
    }

Another One

    public function school_st(){
        return $this->belongsTo('School');
    }

No relation is shown