how to union and groupby in laravel - laravel

Question

i want to get contact id who was send chat or was i send chat to him
with native query i can get result but when i implement in laravel its going difficult
this my native query
select * from `users` where `users`.`id` in (
select `to` from messages where `from` = 2 group by `to`
union
select `from` from messages where `to` = 2 group by `from`
)
what i find difficult is how union after group by or group by after union with make same column number, i using merge but the result is wrong
this what i have try in laravel
$to = Message::select('to')->where('from',auth()->id())->groupBy('to')->get();
$from = Message::select('from')->where('to',auth()->id())->groupBy('from')->get();
$tofrom = $to->merge($from);
dd($tofrom);
please if any body can help

Answer 1

Unions are described in the documentation. To achieve your specific requirements you can do:
$final = User::whereIn('id', function ($query) {
$from = Message::select('from')->where('from',auth()->id())->groupBy('from');
$query->from('messages')->where('to',auth()->id())->groupBy('to')->union($from);
})->get();
Disclaimer: I have not actually tested this but I think it should work.

Answer 2

merge() is the method of collection. Not the Eloquent Builder or Query Builder.
However, It think you want to find user.id in the array.
You can convert the collection to array:
$to = Message::where('from',auth()->id())->groupBy('to')->pluck('to');
$from = Message::where('to',auth()->id())->groupBy('from')->pluck('from');
$tofrom = $to->merge($from)->toarray();
User::whereIn('id', $tofrom)->get();

Answer 3

oh finally i got the answer this is code
$contacts = User::select('users.id','users.name','users.email','users.profile_image')
->join('messages',function($join){
$join->on('users.id','messages.from');
$join->orOn('users.id','messages.to');
})
->where(function($query){
$query->where('messages.from',auth()->id())->orWhere('messages.to',auth()->id());
})
->groupBy('users.id','users.name','users.email','users.profile_image')
->get();