laravel get one of each duplicate column

Question

The structure of the table in the database is as follows:

id	body	user_id	group_id
1	test1	1	1
2	test1	2	1
3	test1	3	1
3	test2	4	2
4	test3	5	3

I want to get the first row from each group_id with Eloquent/DB Facade or MongoDB Query in Laravel with paginate:

For Example:

id	body	user_id	group_id
1	test1	1	1
3	test2	4	2
4	test3	5	3

How is this achievable?

Answer 1

for Mongodb use this aggregation

[
  {
    $sort:{
       group_id: 1,
       user_id:1
    }
  },
  {
    '$group': {
      '_id': {
        'group_id': '$group_id'
      }, 
      'a': {
        '$first': '$$ROOT'
      }
    }
  }
]

Answer 2

Use Eloquent's GroupBy as below, it will fetch the first record from the same group:

DB::table('tablename')
    ->groupBy('group_id')
    ->get();