Order By before Group By using Eloquent (Laravel) - php

Question

I have a "messages" table with the following columns
CREATE TABLE `messages` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`fromId` int(11) NOT NULL,
`toId` int(11) NOT NULL,
`message` text NOT NULL,
`status` int(11) NOT NULL,
`device` varchar(100) NOT NULL,
`createdAt` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=57 DEFAULT CHARSET=latin1;
I'm trying to get all messages where 'toId' = $id and grouping by fromId. The problem is that the "message" shown on the results is the first ones, not the latest ones. I tried ordering by createdAt but it's not working.
How can I order by "createdAt" prior to querying and grouping the results? I want to do this in the laravel way using Eloquent.
My query:
$chats = Message::with('sender','recipient')
->where('toId',$id)
->orderBy('createdAt')
->groupBy('fromId')
->paginate(10)

Answer 1

I just needed to do something similar with a messages model. What worked for me was applying the unique method on the returned eloquent collection.
Model::where('toId', $id)
->orderBy('createdAt', 'desc')
->get()
->unique('fromId');
The query will return all messages ordered by createdAt and the unique method will reduce it down to one message for each fromId. This is obviously not as performant as using the database directly, but in my case I have further restrictions on the query.
Also, there are many more useful methods for working with these collections: https://laravel.com/docs/5.2/collections#available-methods

Answer 2

I found a way to do that! Basically, creating a subquery and running it before, so that results are ordered as expected and grouped after.
Here is the code:
$sub = Message::orderBy('createdAt','DESC');
$chats = DB::table(DB::raw("({$sub->toSql()}) as sub"))
->where('toId',$id)
->groupBy('fromId')
->get();

Answer 3

Try this query :
$chats = Message::with('sender','recipient')
->where('toId',$id)
->whereRaw('id IN (select MAX(id) FROM messages GROUP BY fromId)')
->orderBy('createdAt','desc')
->paginate(10)

Answer 4

It should be something along this:
Message::whereToId($id)->groupBy('fromId')->latest('createdAt')->first();
Update
After seeing the query that you've added, you probably just need to add a direction to the orderBy function, like this:
$chats = Message::with('sender','recipient')
->select(DB::raw('*, max(createdAt) as createdAt'))
->where('toId',$id)
->orderBy('createdAt', 'desc')
->groupBy('fromId')
->paginate(10)

Answer 5

This work for me:
(you can remove the order by createdAt in case createAt increase along with id)
DB::select(DB::raw('select * from (select * from messages group by fromId desc) m order by m.createdAt'));

Answer 6

$data = MCCAddMilkEntry::where('coming_from','=','society')
->whereRaw('id = (select max(`id`) from mcc_add_milk_entry)')->get();

Answer 7

#Sergio your answer is good but what if someone wanted to select a related model along with....?
Answer : I have tested every single function but I didn't fetch the correct data.
unique() gives data with associated array.
groupBy() gives better but picking first message.
Solution for Latest inbox messages. My case:
$data = ChatMessage::where('incoming_msg_id', auth()->user()->id)->orWhere('outgoing_msg_id', auth()->user()->id)->latest('msg_id')->with('messageable')->get();
$inbox = [];
$itemIds = [];
foreach ($data as $key => $value) {
if (!in_array($value['messageable_id'].$value['msg_for'], $itemIds)) {
array_push($inbox,$value);
array_push($itemIds,$value['messageable_id'].$value['msg_for']);
}
}
return $this->sendResponse($inbox,'Inbox');
Your case:
$chats = Message::where('toId',$id)->orWhere('fromId', $id)->latest('id')->with('sender','recipient')->get();
$inbox = [];
$fromIds = [];
foreach ($chats as $key => $value) {
if (!in_array($value['fromId'], $fromIds)) {
array_push($inbox,$value);
array_push($fromIds,$value['fromId']);
}
}
return $this->sendResponse($inbox,'Inbox');