Finding a user with highest post created in last 24 hours, laravel Eloquent

If I'm not wrong, you are asking for the users with the highest number of posts created in the last 24 hrs.

To accomplish this, do the following:

$users = User::withCount(['posts' => function ($query) {
            $query->where('created_at', '>=', carbon()->now()->subDay());
        }])->orderBy('posts_count', 'DESC')
            ->get();

As the documentation states, you can add constraints to the queries.

Counting Related Models

If you want to count the number of results from a relationship without actually loading them you may use the withCount method, which will place a {relation}_count column on your resulting models. For example:

$posts = App\Post::withCount('comments')->get();

foreach ($posts as $post) {
    echo $post->comments_count;
}

You may add the "counts" for multiple relations as well as add constraints to the queries:

$posts = Post::withCount(['votes', 'comments' => function ($query) {
    $query->where('content', 'like', 'foo%');
}])->get();

echo $posts[0]->votes_count;
echo $posts[0]->comments_count;

In regular SQL syntax you'd need something like below:

SELECT COUNT(id), user_id
FROM posts
WHERE created_at = today
GROUP BY user_id
ORDER BY COUNT(user_id) DESC
LIMIT 1;

It gets all the posts, groups them by user_id, sorts them with the highest user_id count up top and gets the first record.

I am by no means an expert on SQL, let alone the query builder in Laravel, so someone else would probably be better at writing that.

I know that you can get the posts that were created today by using Carbon, like so: Post::whereDate('created_at', Carbon::today())->get();

EDIT: This might work for you:

$last24h = Carbon::now()->subDay();

DB::table('posts')
  ->select(array(DB::raw('COUNT(id)', 'user_id')))
  ->where('created_at', '>=', $last24h)
  ->groupBy('user_id')
  ->orderBy('COUNT(id)', 'DESC')
  ->limit(1)
  ->get();

Be sure to include use Carbon\Carbon to be able to use Carbon.

This should give you both the amount of posts and the corresponding user id.

use Carbon\Carbon;

get user id:

 $minusday = Carbon::now()->subDay();
 $user_id = DB::table('posts')
            ->select('user_id', DB::raw('count(id) as total'))
            ->where('created_at', '>=', $minusday)
            ->groupBy('user_id')
            ->orderBy('total','desc')
            ->limit(1)
            ->get();