Not able to update custom field from Apex class, getting "Illegal assignment from List<AggregateResult> to List<Rating_Request__c>" error. can anyone help where I am doing wrong. If possible provide sample code.

Below is my code :

public void updateflgusertb(string Selected)
    {
        
        List<Rating_Request__c> usr = [SELECT ID,Question__c,Order_Sequence__c,User_Ratings__c FROM                     Rating_Request__c where User__c=:UserInfo.getUserId() and User_Rating__c = 0 group by                           ID,Question__c,Order_Sequence__c,User_Ratings__c order by Order_Sequence__c  LIMIT 1];
        List<Rating_Request__c> rateupdate = new List<Rating_Request__c>();  
        for(Rating_Request__c objrating : usr)
        {
            objrating.User_Ratings__c = Selected;
            rateupdate.add(objrating);
        }
        update(rateupdate);
        
    }

Thanks in advance