diff --git a/app/controllers/request_for_comments_controller.rb b/app/controllers/request_for_comments_controller.rb
index 2f8219a9..29c5a6ea 100644
--- a/app/controllers/request_for_comments_controller.rb
+++ b/app/controllers/request_for_comments_controller.rb
@@ -14,46 +14,40 @@ class RequestForCommentsController < ApplicationController
   def index
     @search = RequestForComment
                   .last_per_user(2)
-                  .joins('join "submissions" s on s.id = request_for_comments.submission_id
-                          left outer join "files" f on f.context_id = s.id
-                          left outer join "comments" on comments.file_id = f.id')
-                  .group('request_for_comments.id, request_for_comments.user_id, request_for_comments.exercise_id,
-                          request_for_comments.file_id, request_for_comments.question, request_for_comments.created_at,
-                          request_for_comments.updated_at, request_for_comments.user_type, request_for_comments.solved,
-                          request_for_comments.full_score_reached, request_for_comments.submission_id, request_for_comments.row_number') # ugly, but rails wants it this way
-                  .select('request_for_comments.*, max(comments.updated_at) as last_comment')
+                  .with_last_activity
                   .search(params[:q])
-    @request_for_comments = @search.result.order('created_at DESC').paginate(page: params[:page], total_entries: @search.result.length)
+    @request_for_comments = @search.result
+                                .order('created_at DESC')
+                                .paginate(page: params[:page], total_entries: @search.result.length)
     authorize!
   end
 
+  # GET /my_request_for_comments
   def get_my_comment_requests
     @search = RequestForComment
+                  .with_last_activity
                   .where(user_id: current_user.id)
-                  .joins('join "submissions" s on s.id = request_for_comments.submission_id
-                          left outer join "files" f on f.context_id = s.id
-                          left outer join "comments" on comments.file_id = f.id')
-                  .group('request_for_comments.id')
-                  .select('request_for_comments.*, max(comments.updated_at) as last_comment')
                   .search(params[:q])
-    @request_for_comments = @search.result.order('created_at DESC').paginate(page: params[:page])
+    @request_for_comments = @search.result
+                                .order('created_at DESC')
+                                .paginate(page: params[:page])
     render 'index'
   end
 
+  # GET /my_rfc_activity
   def get_rfcs_with_my_comments
     @search = RequestForComment
+                  .with_last_activity
                   .joins(:comments) # we don't need to outer join here, because we know the user has commented on these
                   .where(comments: {user_id: current_user.id})
-                  .joins('join "submissions" s on s.id = request_for_comments.submission_id
-                          left outer join "files" f on f.context_id = s.id
-                          left outer join "comments" as c on c.file_id = f.id')
-                  .group('request_for_comments.id')
-                  .select('request_for_comments.*, max(c.updated_at) as last_comment')
                   .search(params[:q])
-    @request_for_comments = @search.result.order('last_comment DESC').paginate(page: params[:page])
+    @request_for_comments = @search.result
+                                .order('last_comment DESC')
+                                .paginate(page: params[:page])
     render 'index'
   end
 
+  # GET /request_for_comments/1/mark_as_solved
   def mark_as_solved
     authorize!
     @request_for_comment.solved = true
@@ -66,6 +60,7 @@ class RequestForCommentsController < ApplicationController
     end
   end
 
+  # POST /request_for_comments/1/set_thank_you_note
   def set_thank_you_note
     authorize!
     @request_for_comment.thank_you_note = params[:note]
@@ -82,10 +77,6 @@ class RequestForCommentsController < ApplicationController
     end
   end
 
-  def submit
-
-  end
-
   # GET /request_for_comments/1
   # GET /request_for_comments/1.json
   def show
@@ -146,10 +137,6 @@ class RequestForCommentsController < ApplicationController
     authorize!
   end
 
-  def comment_params
-    params.permit(:exercise_id, :feedback_text).merge(user_id: current_user.id, user_type: current_user.class.name)
-  end
-
   private
     # Use callbacks to share common setup or constraints between actions.
     def set_request_for_comment
@@ -162,4 +149,8 @@ class RequestForCommentsController < ApplicationController
       params.require(:request_for_comment).permit(:exercise_id, :file_id, :question, :requested_at, :solved, :submission_id).merge(user_id: current_user.id, user_type: current_user.class.name)
     end
 
+    def comment_params
+      params.permit(:exercise_id, :feedback_text).merge(user_id: current_user.id, user_type: current_user.class.name)
+    end
+
 end
diff --git a/app/models/request_for_comment.rb b/app/models/request_for_comment.rb
index d0c300b6..d00d08eb 100644
--- a/app/models/request_for_comment.rb
+++ b/app/models/request_for_comment.rb
@@ -10,7 +10,13 @@ class RequestForComment < ActiveRecord::Base
   scope :unsolved, -> { where(solved: [false, nil]) }
 
     def self.last_per_user(n = 5)
-      from("(#{row_number_user_sql}) as request_for_comments").where("row_number <= ?", n)
+      from("(#{row_number_user_sql}) as request_for_comments")
+          .where("row_number <= ?", n)
+          .group('request_for_comments.id, request_for_comments.user_id, request_for_comments.exercise_id,
+                  request_for_comments.file_id, request_for_comments.question, request_for_comments.created_at,
+          request_for_comments.updated_at, request_for_comments.user_type, request_for_comments.solved,
+          request_for_comments.full_score_reached, request_for_comments.submission_id, request_for_comments.row_number')
+          # ugly, but necessary
     end
 
   # not used right now, finds the last submission for the respective user and exercise.
@@ -46,6 +52,14 @@ class RequestForComment < ActiveRecord::Base
     commenters.uniq {|user| user.id}
   end
 
+  def self.with_last_activity
+    self.joins('join "submissions" s on s.id = request_for_comments.submission_id
+                left outer join "files" f on f.context_id = s.id
+                left outer join "comments" c on c.file_id = f.id')
+        .group('request_for_comments.id')
+        .select('request_for_comments.*, max(c.updated_at) as last_comment')
+  end
+
   def to_s
     "RFC-" + self.id.to_s
   end