Can you query an array? Laravel 5.2 - php

Question

Maybe a silly question here, but I am working on an app where we need to calculate some basic demographic stats. I want to make a trip to the data base once and then try and query that array of Eloquent models. Right now I am getting an array using the query, and then looping through it to count some stats.
i.e.
$people = Person::all();
$total = count($people);
$count = 0;
foreach($people as $person)
if($person->age > 60) {
count++;
}
}
$percent = $count/$total;
Which works but we have to do this for hundreds of data points.
Can I do something like this?
i.e.
$people = Person::all();
$total = count($people);
$count = $people->where('age', '>=', '60')->count();
$percent = $count/$total;
My thought is that the latter will be more efficient (if possible) because it only makes one trip to the database and doing the aggregate stuff on server side? Or would it be better to make multiple queries and get the database to do all the aggregate stuff?
Thanks,
Matt

Answer 1

You want Collections.
https://laravel.com/docs/5.2/collections
Collections in Laravel are handy Array wrappers that provide additional logic that is very similar to the ODB structure. In fact, when you get Eloquent results, you get a special Database collections.
https://laravel.com/api/5.1/Illuminate/Support/Collection.html
https://laravel.com/api/5.1/Illuminate/Database/Eloquent/Collection.html
You can use a variety of logic on both of these object types that are basically identical to Builders for Eloquent DB queries.

Answer 2

Yes you can, Eloquent has an aggregate count method, try this:
$total = Person::count();
$count = Person::where('age', '>=', '60')->count();
$percent = $count/$total;

Answer 3

It would be more efficient to query the database once, and then filter the resulting collection:
$people = Person::all();
$total = count($people);
$peopleOver60 = $people->filter(function($item) {
return $item->age >= 60;
});
$percent = count($peopleOver60) / $total;

Answer 4

Yes is great for performance
and You can change your code like that :$people to Person::
$people = Person::all();
$total = count($people);
$count = Person::where('age', '>=', '60')->count();
$percent = $count/$total;

Answer 5

Your database optimized for searching queries but PHP isn't. You should use your "where" queries in DB. But if you want it anyway you can check this library :
https://phplinq.codeplex.com/