Laravel : insert into pivot table-CodePudding

I'm trying to connect profiles with groups using a pivot table. What I want is to use tinker to add students profiles in study groups.

I don't know what I'm doing wrong but I can't make tinker write to the DB (I know how to do it with OneToOne and oneToMany relationships).

My Profile model has the following function :

    public function isStudentInGroup() 
{
    return $this->belongsToMany(Group::class);
}

My Group model has the following function :

    public function hasStudents() 
{
    return $this->belongsToMany(Profile::class);
}

In tinker, I start by grabbing a Profile and a group :

$profile = Profile::find(1);
$group = Group::find(1);

Then I want to add the group to the isStudentInGroup collection. How do I do it? Here's what I've tried until now. No matter what I do, everytime I use fresh() I see an empty collection.

$profile->isStudentInGroup->save($group);
$profile->isStudentInGroup->save($group->id);
$profile->isStudentInGroup->attach($group->id);
Profile::find(1)->isStudentInGroup->push(1)->update();
Profile::find(1)->isStudentInGroup->push(1)->save();

These all give BadMethodCallException errors.

A promising syntax was this one :

$profile->isStudentInGroup->push($group)
=> Illuminate\Database\Eloquent\Collection {#4646
 all: [
   App\Models\Group {#5012
     id: "1",
     start_time: "2022-09-05 18:10:00",
     end_time: "2022-09-05 19:00:00",
     created_at: null,
     updated_at: null,
     pivot: Illuminate\Database\Eloquent\Relations\Pivot {#5020
       profile_id: "1",
       group_id: "1",
     },
   },
 ],
}

But then, if I tried to $profile->save(); or $profile->update(); I would get the following

BadMethodCallException with message 'Method Illuminate\Database\Eloquent\Collection::update does not exist.'

What am I missing?

Thanks in advance.

EDIT :

Thanks to matiaslauriti I got the syntax right:

$profile->isStudentInGroup()->save($group);

I also went fishing for knowledge and found this related question with a helpful answer from McHobbes that helped me understand the logic behind the parentheses. Why eloquent model relationships do not use parenthesis and how do they work?

CodePudding user response：

Pardon me if I did not understand, but you want to make a relation between those relationships, so you have to run:

$profile->isStudentInGroup()->save($group->id);

That should trigger storing that group inside that relationship. If it does not work, I think this will should (or may also work):

$profile->isStudentInGroup()->attach($group->id);

But you must use the relationship, not the Collection. You are mixing relationships objects with Collections, that is why the error says:

Method Illuminate\Database\Eloquent\Collection::update does not exist.

A Collection does not have update or save as it is a collection, it can't be saved anywhere, but a relationship can.

CodePudding user response：

Try this

App\Models\Profile::find(1)->isStudentInGroup;

i hope it was useful .