laravel group by fetch latest record from table - laravel

Question

I have one table where I want to retrieve data group by the user but I want the latest entry in result how can I do that by using eloquent.
here is an eloquent query I am using.
Product::whereNotNull('user_id')
->orderBy('id','desc')
->groupBy('user_id')
->get();
here is my table
Id Name user_id
-------------------------
1 A 1
2 b 1
3 c 2
4 d 2
5 e 3
6 f 3
result my query is giving me
Id Name user_id
-------------------------
1 A 1
3 c 2
5 e 3
result i want
Id Name user_id
-------------------------
2 b 1
4 d 2
6 f 3

Answer 1

Product::whereRaw('id IN (select MAX(id) FROM products GROUP BY user_id)')
->whereNotNull('user_id')
->orderBy('id','desc')
->get();
You will need a nested query for that, i don't think you can avoid it but this solution should work.
GroupBy happens before OrderBy so you have to get your last record before you do your ordering

Answer 2

Try this :
$subquery = Product::orderBy('id','DESC');
$products = DB::table(DB::raw("({$subquery->toSql()}) as subquery"))
->whereNotNull('user_id')
->groupBy('user_id')
->get();
2nd way : use unique() method in collection (The unique method returns all of the unique models in the collection):
$products = Product::whereNotNull('user_id')
->orderBy('id','desc')
->get()
->unique('user_id');

Answer 3

Check out Laravel Docs
latest / oldest
The latest and oldest methods allow you to easily order results by date. By default, result will be ordered by the created_at column. Or, you may pass the column name that you wish to sort by:
$product = Product::latest()->first();