Laravel reducing relationship queries - laravel

Question

I have two models. Expense and Method. I want to grab the sum of all expenses for each method type. I have four types:
- bank
- credit-card
- wallet
- savings
Each Expense belongsTo a Method and each Method hasMany Expenses. So it's a One-to-Many relation. So a method_id is stored for each Expense.
The following query works to get the sum of all expenses that have a method with the type bank for example:
$type = 'bank';
$expenses = auth()->user()->expenses()->with('method')->whereHas('method', function ($query) use ($type) {
$query->where('type', $type);
})->sum('amount');
But the thing is, if I want to get the total amount of all expenses for each method type, I will have to run too many queries. I would prefer just grabbing all Expenses, and then filtering through them to get the sum of all expenses for each method type.
The following for example doesn't work:
$expenses = auth()->user()->expenses()->with('method')->get();
$bank_balance = $expenses->filter(function ($expense)
{
$expense->whereHas('method', function ($query) {
$query->where('type', 'bank');
})->get(); // with or without ->get()
});
Any ideas how to get what I want by not using too many queries?
Edit:
I've unaccepted the chosen answer because it didn't give me what I needed in the end. I need to be able to do something like this in my view:
{{ $bank_balance }}
Which means, with xyz's answer, I wouldn't be able to do that, since I cannot distinguish between them. I only get results based on method_id's, but I need to be able to distinguish them by the method name.
DigitalDrifter's answer is the one that almost does the trick, but it gives me this:
Collection {#800 ▼
#items: array:3 [▼
"bank" => Collection {#797 ▼
#items: array:30 [▼
0 => array:2 [▼
"type" => "bank"
"amount" => 1536
]
1 => array:2 [▶]
2 => array:2 [▶]
3 => array:2 [▶]
4 => array:2 [▶]
5 => array:2 [▶]
]
}
"credit-card" => Collection {#798 ▶}
"wallet" => Collection {#799 ▶}
]
}
And I basically need something simple like this:
"bank" => "total sum here for all expenses that have a method of 'bank'"
"credit-card" => "total sum here for all expenses that have a method of 'credit-card'"
And so on..
I think this bit ->groupBy('type')->each->sum('amount') does the trick, but not completely. It does group by type but it does not give a sum for each type, as you can see in the collection example above.

Answer 1

You can group by the method id and then sum the result in a select statement.
The following is untested.
$expenses = auth()->user()
->expenses()
->select(DB::raw('SUM(amount) as total'), 'other_select_fields', ...)
->with('method')
->groupBy('method_id')
->get();

Answer 2

You could do this using the available collection methods:
$expenses = auth()->user()->expenses()->with('method')->get();
$groupedSums = $expenses->map(function ($expense) {
return [
'type' => $expense['method']['type'],
'amount' => $expense['method']['amount']
];
})->groupBy('type')->each->sum('amount');