Laravel DB Schema when referencing to two tables

Question

There a able, called 'interests' which hold the id(s) of 'categories' and/or 'brands' that each user has interest in. To prevent creating two separate tables for user_category_interests and user_brand_interest I added an enum column called type.

Now I can't figure out how should I create a migration in Schema Builder, How to set relations and foreign keys,... to take advantage of using Eloquent methods.

    Schema::create('user_interests', function (Blueprint $table) {
        $table->increments('id');
        $table->enum('type', ['categories', 'brands']);
        $table->integer('reference_id')->unsigned();
        $table->timestamps();
    });

Is there any better way instead of creating two separate tables and models?

P.S. I use laravel 5.4

Brands Table:
id  |  name
-----------
1   | Adidas
2   | Nike
3   | Puma

Categories Table:
id  |  name
-----------
1   | Clothes
2   | Luxury
3   | Sport Wear


User_Interests Table:
id  | user_id |   type   | reference_id
-----------------------------------------
1   | 113     | 'brand'  | 2
1   | 113     | 'brand'  | 3
2   | 113     |'category'| 3
3   | 224     | 'brand'  | 1

Answer 1

Yes - read the docs on polymorphic relations.

It works similar to what you have, but you might have columns called interestable_id and interestable_type (you can configure this to something else if you prefer). The interestable_type will literally be the string representation of the referenced class name, like App\Brand or App\Category and interestable_id will be the primary key of that model.

Best part is as it's all done through Eloquent it's already good to go with associations, eager-loading etc.

Edit: I should add that your 3 table setup is still the best way to represent this structure, just making suggestions on the column names you use and how to hook it in with Eloquent.