Laravel count has many through without n+1 - laravel

Question

I have 4 models that are relevant.
Company
Location
Customer
ThirdPartyLinkClick
Company.php
public function locations() {
return $this->hasMany('App\Location');
}
Location.php
public function customers() {
return $this->hasMany('App\Customer');
}
public function linkClicks() {
return $this->hasManyThrough('App\ThirdPartyLinkClick', 'App\Customer');
}
Customer.php
public function linkClicks() {
return $this->hasMany('App\ThirdPartyLinkClick');
}
There is no issue when acquiring the count of link clicks for all customers when on a single Location.
I can simply do: $this->linkClicks->count(); which creates a query where it does a WHERE IN (1,2,3,4, etc) query
However, on a Company page, I want to also get this count, but avoid an n+1
Right now, my model method on Company.php is
public function getTotalClicksToReviewSites() {
$locations = $this->locations;
$clicks = 0;
foreach ($locations as $location) {
$clicks += $location->linkClicks->count();
}
return $clicks;
}
This creates duplicate queries where it checks location_id on each query. There will be a query for every location rather than checking a group of id's in a WHERE IN statement.
How can I do an eloquent query that will use a single query to gather this data? I only need the count.

Answer 1

You need to use eager loading.
$companies = Company::with('locations', 'locations.linkClicks')->get();
This prevents n + 1 query problem, so, to get te total of linkClicks for each company youur function will work or simply you can do.
$companies = Company::with('locations', 'locations.linkClicks')
->get()
->map(function ($company) {
$company->linkClicksCount = $company->locations->sum(function ($location) {
return $location->linkClicks->count();
});
return $company;
});
The output should be something like this (a new property linkClicksCount added on each company).
[
{"id": 1, "name": "Company 1", "linkClicksCount": 9, "locations": [], ...},
{"id": 2, "name": "Company 2", "linkClicksCount": 3, "locations": [], ...},
...
]