OrderBy is not working while applying GroupBy Laravel - php

Question

I am using following query to retrieve the user feeds but ordering latest update is not working when we applying order created_at time by desc
Here i have given SQL query. Kindly suggest me solution to solve my problem
select `users`.`id` as `uid`, `updates`.`post_id`, `updates`.`id` as `upid`, `friends`.`id` as `fid`, `updates`.`user_id`, `updates`.`privacy`, `updates`.`updated_at`, `updates`.`created_at`, `friends`.`first_user_id`, `friends`.`second_user_id`, `friends`.`friend_status`, `updates`.`update_type` from `updates`
inner join `users` on `updates`.`user_id` = `users`.`id`
inner join `friends` on
CASE
WHEN friends.first_user_id = 1
THEN friends.second_user_id = updates.user_id
WHEN friends.second_user_id= 1
THEN friends.first_user_id = updates.user_id
END
where `friends`.`friend_status` > 0
and `updates`.`privacy` in (1,2)
and `updates`.`user_id` != 1 and
`updates`.`deleted_at` is null
group by `updates`.`post_id`
order by `updates`.`created_at` desc
Laravel Code
Update::select(
'users.id as uid', 'posts.id as pid', 'updates.post_id', 'updates.id as upid',
'friends.id as fid', 'updates.user_id', 'updates.privacy', 'updates.updated_at', 'updates.created_at', 'posts.deleted_at', 'friends.first_user_id',
'friends.second_user_id', 'friends.friend_status', 'updates.update_type', 'posts.wall_user_id'
)->join('users', 'updates.user_id', '=', 'users.id')
->join('posts', 'posts.id', '=', 'updates.post_id')
->join('friends', function($join) use ($userId){
$join->on(DB::raw('CASE
WHEN friends.first_user_id = '.$userId.'
THEN friends.second_user_id = updates.user_id
WHEN friends.second_user_id= '.$userId.'
THEN friends.first_user_id = updates.user_id
END'
), DB::raw(''), DB::raw(''));
})->where('friends.friend_status', '>', 0)
->whereIn('updates.privacy', [1,2])
->where('updates.user_id', '!=', Auth::user()->id)
->groupBy('updates.post_id')
->orderBy('updates.created_at', 'DESC')
->get();

Answer 1

select * from(select `users`.`id` as `uid`, `updates`.`post_id`, `updates`.`id` as `upid`, `friends`.`id` as `fid`, `updates`.`user_id`, `updates`.`privacy`, `updates`.`updated_at`, `updates`.`created_at`, `friends`.`first_user_id`, `friends`.`second_user_id`, `friends`.`friend_status`, `updates`.`update_type` from `updates`
inner join `users` on `updates`.`user_id` = `users`.`id`
inner join `friends` on
CASE
WHEN friends.first_user_id = 1
THEN friends.second_user_id = updates.user_id
WHEN friends.second_user_id= 1
THEN friends.first_user_id = updates.user_id
END
where `friends`.`friend_status` > 0
and `updates`.`privacy` in (1,2)
and `updates`.`user_id` != 1 and
`updates`.`deleted_at` is null order by `updates`.`created_at` desc) as tmp_table
group by `updates`.`post_id`