How to select the last entry in each group in Laravel?

Question

MySQL

There is a table with messages, the structure is simple: id, sender, recipient, chat_id
I need to display the last message in each of the chats
. Grouping by chat_id via ->groupBy('chat_id') gives the first entry.
->orderBy('id','desc') doesn't work here.
How to do?

Answer 1

And if you try by the maximum id?
max('id')

Answer 2

Make hasOne relation in Chat model

public function lastMessage()
{
  return $this->hasOne('App\Models\Message','chat_id', 'id')->latest();
}

In the controller in the template

@foreach ($chats as $chat)
  {{ $chat->lastMessage->name }}
@endforeach