Laravel Carbon Group by Month

Question

Can anyone see what I'm doing wrong?

I'm trying to output all the months but group them so they are unique.

$months = NewsItem::select(DB::raw('MONTH("created_at") as month'))->groupBy('month')->get();
return $months;

I'm getting the following back

{"month":null}

In my database I have five news articles all created_at 05/01/2017 so it's right that I only get one response but I'm not getting the number of the month back?

Answer 1

You can use groupBy() method with closure:

 $months = NewsItem::groupBy(function($d) {
     return Carbon::parse($d->created_at)->format('m');
 })->get();

Or get data first and then use groupBy() on the Eloquent collection:

 $months = NewsItem::get()->groupBy(function($d) {
     return Carbon::parse($d->created_at)->format('m');
 });

Answer 2

Why do you need the group by clause in your usecase?

You are not fetching any additional data for which a group by is required, you just want to have a list of distinct months, so use distinct.

$months = NewsItem::selectRaw("MONTH(created_at) as month")->distinct()->get();

Also looking at the solution provided by Alexey, you'll need to fetch the entire dataset from the DB, which is highly inefficient looking at what you are trying to do. A distinct() query would be much faster than a select * and group the results in PHP.

Edit:

Little sidenote here, the reason you get null returned as value is because you use a string in the MONTH() function instead of the actual field.