there is a user ranking table, which needs to be sorted by score and output. If there is a duplicate user, take the highest score of that user 
 now I write 
DB::select("SELECT nickname, id, fraction, FIND_IN_SET( fraction, (    
                    SELECT GROUP_CONCAT( fraction
                    ORDER BY fraction DESC ) 
                    FROM fan_rankings WHERE test_id=$test_id)
                    ) AS rank
                    FROM fan_rankings
                    WHERE test_id = $test_id AND user_id = $user->id ORDER BY fraction DESC"); I added a GROUP BY (user_id before ORDER BY), but if there is an error, please tell me what to do 
 and how to write it in ORM. I feel it"s a bit complicated to write in native 
 my own version of laravel5.4 
 Please don"t hesitate to give me your advice 
