How to setup conditional relationship on Eloquent

Question

I have this (simplified) table structure:

users
- id
- type (institutions or agents)

institutions_profile
- id
- user_id
- name

agents_profile
- id
- user_id
- name

And I need to create a profile relationship on the Users model, but the following doesn't work:

class User extends Model
{
    public function profile()
    {
        if ($this->$type === 'agents')
            return $this->hasOne('AgentProfile');
        else
            return $this->hasOne('InstitutionProfile');
    }    
}

How could I achieve something like that?

oseintow · Accepted Answer · 2017-04-27T22:39:15.033

33

Lets take a different approach in solving your problem. First lets setup relationship for the various models respectively.

class User extends Model
{
    public function agentProfile()
    {
        return $this->hasOne(AgentProfile::class);
    }    

    public function institutionProfile()
    {
        return $this->hasOne(InstitutionProfile::class);
    }

    public function schoolProfile()
    {
        return $this->hasOne(SchoolProfile::class);
    }

    public function academyProfile()
    {
        return $this->hasOne(AcademyProfile::class);
    }

    // create scope to select the profile that you want
    // you can even pass the type as a second argument to the 
    // scope if you want
    public function scopeProfile($query)
    {
        return $query
              ->when($this->type === 'agents',function($q){
                  return $q->with('agentProfile');
             })
             ->when($this->type === 'school',function($q){
                  return $q->with('schoolProfile');
             })
             ->when($this->type === 'academy',function($q){
                  return $q->with('academyProfile');
             },function($q){
                 return $q->with('institutionProfile');
             });
    }
}

Now you can access your profile like this

User::profile()->first();

This should give you the right profile. Hope it helps.

edited Apr 27 '17 at 22:39

answered Apr 27 '17 at 22:10

oseintow

7,221
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I'm not sure this applies. I need to be able to eager load the profile and access $user->profile->name. – Ju Nogueira Apr 27 '17 at 22:24
Check the scope well. It is eager loading the profile(base on the type) and am using **with** to eager load which is more efficient preventing any N+1 query problems. i have changed your if statement to a more laravel like eloquent syntax – oseintow Apr 27 '17 at 22:25
Yes, you're right. But what if I have more profile types? – Ju Nogueira Apr 27 '17 at 22:35
Have updated the answer. You can use if statement if you feel more convenient with that. – oseintow Apr 27 '17 at 22:40
Seems perfect. Thank you! – Ju Nogueira Apr 27 '17 at 22:58
Help me, I use it for my code, but, always returns the relation 'user_share', even when type is 1... – Valter Sousa Cardoso Mar 10 '18 at 16:58
4

This will not work due to the "user" object not being loaded when the scope runs. Thus "$this->type" will always be null when loading the user. You would have to first load the user and only *then* run the rest of the code. – Andrei Gabreanu Jan 05 '19 at 11:30
@AndreiGabreanu, what do you mean by loading the user first? I'm getting null on "$this->type". – Nehal Jan 03 '21 at 17:15
its giving me $this->type as null how did you guys solve the proble – Kunal Rajput Jul 07 '21 at 16:22
Without eager loading possibility this is not the right answer – Bartłomiej Sobieszek Sep 29 '21 at 03:44

score 6 · Answer 2 · answered Apr 27 '17 at 22:01

6

you can do this by use another method please check this:

a blog Post and Video model could share a polymorphic relation to a Tag model. Using a many-to-many polymorphic relation allows you to have a single list of unique tags that are shared across blog posts and videos. First, let's examine the table structure:

https://laravel.com/docs/5.4/eloquent-relationships#many-to-many-polymorphic-relations

answered Apr 27 '17 at 22:01

Mortada Jafar

3,529
1
18
33

2

Thanks, but polymorphic relations doesn't apply here. – Ju Nogueira Apr 27 '17 at 22:05
3

I think polymorphic is right here, but you need to restructure your database slightly. – Zoe Edwards Feb 23 '18 at 15:24

score 0 · Answer 3 · answered Apr 27 '17 at 21:34

0

Looks like that should be $this->type rather than $this->$type - since type is a property, not a variable.

answered Apr 27 '17 at 21:34

Joel Hinz

24,719
6
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75

I just can't believe I didn't see that! Thanks. But now I'm getting this error when trying to eager load the profile: `Fatal error: Call to a member function addEagerConstraints() on a non-object in /vendor/illuminate/database/Eloquent/Builder.php on line 667` Any ideas? – Ju Nogueira Apr 27 '17 at 21:58
Not sure exactly what might cause that - maybe check the names of the tables/models? I noticed they're called different things so they might need `$table` properties in their respective models. – Joel Hinz Apr 27 '17 at 21:59
Have just seen that message about `addEagerConstraints` - this is caused when your relationship function (e.g `profile()`) doesn't return anything - suspect a scope is the better way to go. – GuruBob Apr 18 '19 at 02:05

How to setup conditional relationship on Eloquent

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