Check out example codes for "sql select sum group by id laravel". It will help you in understanding the concepts better.

Code Example 1

Document::groupBy('users_editor_id')
   ->selectRaw('sum(no_of_pages) as sum, users_editor_id')
   ->pluck('sum','users_editor_id');

   // originally lists(), which was deprecated in favour of pluck in 5.2
   // and dropped completely in 5.3
   // ->lists('sum','users_editor_id');


// returns array like this:
array(
  users_editor_id => sum,
  ...
)

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