Get a collection of relationship items through multiple relations in Laravel - php

Question

I have the following relationships:
Users have polymorphic many to many (morphedByMany) relationships with Customers, Locations, and Vendors.
Customers, Locations, and Vendors each have hasMany or hasManyThrough relationships with Datasets.
I'd like to get the Datasets that a given User has access to via its relationships. Also, some of the datasets through the different relationships might be the same, so I want a unique list.
I created the following method on my User model that works correctly (inspired by Laravel get a collection of relationship items):
public function accessibleDatasets()
{
$datasetsByCustomers = $this->customers()->with('datasets')->get()->pluck('datasets')->flatten();
$datasetsByLocations = $this->locations()->with('datasets')->get()->pluck('datasets')->flatten();
$datasetsByVendors = $this->vendors()->with('datasets')->get()->pluck('datasets')->flatten();
$datasets = $datasetsByCustomers;
$datasets = $datasets->merge($datasetsByLocations);
$datasets = $datasets->merge($datasetsByVendors);
return $datasets->unique();
}
Is there a "right way" or more efficient way to get this (besides using some sort of a reduce function for the merges)? Is loading the models, then flattening better? The associated values aren't going to change too often, so I can cache the results, but wanted to get some feedback.

Answer 1

The most efficient way would be by performing a single database query as Tim already mentioned.
Since you can cache the results and should you want to spare some lines of code I'd rather do:
public function accessibleDatasets()
{
$this->load('customers.datasets', 'locations.datasets', 'vendors.datasets');
return $this->customers->flatMap->datasets
->merge($this->locations->flatMap->datasets)
->merge($this->vendors->flatMap->datasets);
}
The merging operation should take care of duplicate keys but feel free to add a unique call if it doesn't.