CODEWITHSUNDEEP
phplaraveleloquent
Ryan Knopp
Ryan Knopp

Reputation: 612

Laravel many to many with a pivot relationship.

User

Provider

Resolution

ProviderResolution

ProviderResolutionUser

class Provider extends Model {  

    public function resolutions()
    {
        return $this->belongsToMany('App\Models\Resolution')->withPivot('active')->withTimestamps();
    }

}

class Resolution extends Model {

    public function providers()
    {
       return $this->belongsToMany('App\Models\Provider')->withPivot('active')->withTimestamps();
    }
}

 class User extends Model 
 {

 }

Trying to create a Eloquent relationship with this.

I'm trying to figure out how to fit user into this model. It seems like it's suppose to belongsToMany. Do I need to create a class that represents the pivot?

Then from the case of the User how would I query a list resolutions?

Upvotes: 0

Views: 154

Answers (1)

Mark C.
Mark C.

Reputation: 606

You didn't ask but I personally think it's a lot easier to let the primary key of each table be 'id.' Also, in the case of ProviderResolution, unless you have a specific case for it, you don't need (and shouldn't use) 'prid' at all. Just 'pid', 'rid' and 'active' should be sufficient. The 'pid' and 'rid' make the composite primary key on their own. If you add yet another key ('prid'), then there will be a three-key composite which will technically enable you to have duplicates with your other two primary keys. Yuck. Example: PRID:1, PID:1, RID:1, then PRID:2, PID:1, RID:1. Now you have duplicates but your record is technically still unique because of the PRID key. But, maybe you want it this way for some reason?

For the answer I'm going to assume you are using Laravel 5.4+. So first off, you don't need a class for the pivot. And secondly, you are currently trying to create a relationship between the user and the existing pivot table between Provider and Resolution by creating a table called 'provider_resolution_user'. If you want to query resolutions for a user, just use the relationship methods which gives you access to the attributes on the pivot table and the related models/tables.

First, setup the 'hasMany' relationships in both classes: Users and Resolutions (Providers already has a relationship to Resolutions, so you can use that relationship if you want to see the related Provider.) Then you'll need a pivot table called 'resolution_user'. Put the 'uid' and the 'rid' in the table. Make the relationships to the corresponding foreign key fields to their parent tables.

Now you can access the relationship directly like:

$user->resolutions->rid (or whatever the attribute is you want)

The previous example assumes you have already created a way to insert records into the pivot table (resolution_user) that relate the user and the resolution together.

If you want to access one of the attributes on the pivot table, 'pivot' creates an object instance with it's own attributes (from the table). You can access it like this:

$user->resolutions->pivot->active;

Of course, these methods are chainable so if you just wanted to see the active resolutions, you could also add a ->where statement.

Hope that helps and wasn't too muddy. I'm happy to clarify any points if need be.

EDITED ANSWER:

Because what you want to do is to disable a row in the provider_resolution table and have that reflect on the correct user, then just create a relationship in both the User model and the Resolution model. So when you disable a row in provider_resolution (pid, rid, active), you can lookup the appropriate user to update by using the inverse relationship between resolution and user. This should give you the user that is assigned to that particular resolution/provider combination. If for some reason you do need to find the user based on a unique combination of the TWO: resolution AND provider, then we might need to talk about polymorphic relationships. Let me know.

Upvotes: 1

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