How to group Collection with daily dates yyyy-mm-dd by month and/or years?

Nevermind, I usually find the solution, AFTER I ask.

$weeklyQuotes = $quotes->groupBy(function($item) {
    return Carbon::createFromFormat('Y-m-d', $item->date)->format('Y-W');
 });
$monthlyQuotes = $quotes->groupBy(function($item) {
    return Carbon::createFromFormat('Y-m-d', $item->date)->format('Y-m');
});
$yearlyQuotes = $quotes->groupBy(function($item) {
    return Carbon::createFromFormat('Y-m-d', $item->date)->format('Y');
});

@dirkolbrich

$collection->groupBy(function ($item) {
  return $item->date->format('Y-m'); // given date is mutated to carbon by eloquent..
  return (new \DateTime($item->date))->format('Y-m'); // ..othwerise
})->reduce(function ($result, $group) {
  return $result->put($group->first()->date->format('Y-m'), collect([
    'min' => $group->min('value'),
    'max' => $group->max('value'),
  ]));
}, collect());

// you get something like this:
Illuminate\Support\Collection {#873
     all: [
       "2015-10" => Illuminate\Support\Collection {#870
         all: [
           "min" => 1
           "max" => 1
         ]
       }
       "2015-07" => Illuminate\Support\Collection {#1002
         all: [
           "min" => 123
           "max" => 126
         ]
       }
       "2015-05" => Illuminate\Support\Collection {#865
         all: [
           "min" => 21
           "max" => 122
         ]
       }
       "2015-03" => Illuminate\Support\Collection {#1003
         all: [
           "min" => 2
           "max" => 20
         ]
       }
     ]
   }

Mind that with high volume of these items, you may want to use sql instead, since collection methods are slower.

Ah, sorting by date and fetching min/max values in one query sounds interesting. Thanks for the hint, will test it.

Why would you ask if you already know the answer anyway?

@robbiermann Pretty sure he has moved on after 4 years... Also he found it AFTER he asked the question. It's litterly in the Green answer area.

According to the 1027 views on the page, he must have helped some people even with his own answer :)