How to Define Relationships Between Models in Different Databases (MongoDB and MySQL) in Laravel?

Is it possible in Laravel to define a relationship between two models that reside in different databases, specifically when one model is stored in MongoDB and the other in MySQL? For example, I have a MySQL model that needs to load related data from a MongoDB model. Are there any recommended approaches or best practices to make this work smoothly, especially for eager loading or other types of relationships? Any guidance would be greatly appreciated!

vincent15000

1 year ago

Best Answer

Level 63

If you are working with relationships, it's not a good idea to use MongoDB which is a noSQL database.

About your question, I think that it's not possible to eager load exactly as in a pure Laravel / MySQL application. The query is created and sent to one database.

As you need to retrieve the datas from 2 different databases, you can first retrieve data from MySQL.

// MySQL
$books = Book::all();

And then retrieve the related data from MongoDB.

$categoriesIds = array_unique($books->pluck('category_id')->toArray());

// MongoDB
// but here with perhaps another syntax appropriated with a MongoDB ORM (not sure that Eloquent can retrieve datas from MongoDB, never tested)
$categories = Category::whereIn('id', $categoriesIds)->get();

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laithalenooz

1 year ago

Level 1

@vincent15000 The issue is that I'm forced to use MongoDB with SQL, we have logs stored in mongo with morph relation, I think it will cause a load if I go with this approach. Thank you for your answer!

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