Pivot model relationships for many to many

I am making a feature where users can purchase packages.

Here's the current database schema for each of the tables.

Packages table: This table stores information about the available packages.

+--------------+--------------+------+-----+---------+----------------+
| Field        | Type         | Null | Key | Default | Extra          |
+--------------+--------------+------+-----+---------+----------------+
| id           | int(11)      | NO   | PRI | NULL    | auto_increment |
| name         | varchar(255) | NO   |     | NULL    |                |
| description  | text         | YES  |     | NULL    |                |
| price        | decimal(10,2)| NO   |     | NULL    |                |
+--------------+--------------+------+-----+---------+----------------+

Users table: This table stores information about the users.

+--------------+--------------+------+-----+---------+----------------+
| Field        | Type         | Null | Key | Default | Extra          |
+--------------+--------------+------+-----+---------+----------------+
| id           | int(11)      | NO   | PRI | NULL    | auto_increment |
| name         | varchar(255) | NO   |     | NULL    |                |
| email        | varchar(255) | NO   |     | NULL    |                |
| password     | varchar(255) | NO   |     | NULL    |                |
+--------------+--------------+------+-----+---------+----------------+

User_Packages table: This table represents the relationship between users and the packages they have purchased.

+--------------+---------+------+-----+---------+----------------+
| Field        | Type    | Null | Key | Default | Extra          |
+--------------+---------+------+-----+---------+----------------+
| id           | int(11) | NO   | PRI | NULL    | auto_increment |
| user_id      | int(11) | NO   | MUL | NULL    |                |
| package_id   | int(11) | NO   | MUL | NULL    |                |
| purchase_date| date    | NO   |     | NULL    |                |
+--------------+---------+------+-----+---------+----------------+

From what I think, this is a many-to-many relationship.

My question is, is it okay to add relationships inside the Pivot model?

UserPackage Pivot model:

class UserPackage extends Pivot
{
    // Define the relationship with User model
    public function user()
    {
        return $this->belongsTo(User::class);
    }

    // Define the relationship with Package model
    public function package()
    {
        return $this->belongsTo(Package::class);
    }
}

LaryAI

2 years ago

Level 58

Yes, it is perfectly fine to add relationships inside the Pivot model. In fact, that's the recommended approach when working with many-to-many relationships in Laravel.

The code you provided for the UserPackage Pivot model is correct. It defines the relationships with the User and Package models using the belongsTo method. This allows you to easily access the related User and Package models from a UserPackage instance.

To use these relationships, you can simply access them as properties on a UserPackage instance. For example:

$userPackage = UserPackage::find(1);

// Access the related User model
$user = $userPackage->user;

// Access the related Package model
$package = $userPackage->package;

You can also eager load these relationships to avoid the N+1 query problem. For example:

$userPackages = UserPackage::with('user', 'package')->get();

foreach ($userPackages as $userPackage) {
    // Access the related User model
    $user = $userPackage->user;

    // Access the related Package model
    $package = $userPackage->package;
}

Overall, your approach is correct and you can continue using the relationships inside the Pivot model as you have defined.

NoLAstNamE

2 years ago

Level 8

@LaryAI Since this is an answer from Lary the AI, it's better to wait for someone to confirm this.

Snapey

2 years ago

Level 122

It is many to many between packages and users, but in this case the intermediary also has standing in your application as a Pivot Model

so whilst you can define many to many relationships on User and Package, you can also define relationships between the pivot model and the other two, exactly as you have shown, and from the user to user_packages and package to user_oackage

A naming change might make it clearer, for instance, the user_packages table could be called transactions or purchases or subscriptions, and have the same relationships. I see you have a purchase date column so uou are already leaning towards 'purchases'

1 like

NoLAstNamE

2 years ago

Level 8

@Snapey Thanks for the insights. If I understand it correctly I can change my intermediary pivot model and table to purchases and then leave the relationship in the pivot model as it is.

Purchase Pivot Model:

// App/Models/Purchase.php

class Purchase extends Pivot
{
    // Define the relationship with User model
    public function user(): BelongsTo
    {
        return $this->belongsTo(User::class);
    }

    // Define the relationship with Package model
    public function package(): BelongsTo
    {
        return $this->belongsTo(Package::class);
    }
}

and then in the User and Package model, I will chain ->using(Purchase::class) in the belongsToMany relationships.

// App/Models/Package.php

public function packages(): BelongsToMany
{
    return $this->belongsToMany(Package::class)->using(Purchase::class)->withPivot('purchase_date')->withTimestamps();
}


// App/Models/Package.php

public function users(): BelongsToMany
{
    return $this->belongsToMany(User::class)->using(Purchase::class)->withPivot('purchase_date')->withTimestamps();
}

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