fix sort error in paginator concern and change learning_objects index

app/controllers/concerns/paginator.rb

@@ -54,7 +54,7 @@ module Paginator
 
       # ordering
       to_sort = JSON.parse params[:sort] if !params[:sort].blank?
-      model = model.order("#{to_sort[0]} #{to_sort[1]}") if !to_sort.blank?
+      model = model.order("\"#{model.table_name}\".\"#{to_sort[0]}\" #{to_sort[1]}") if !to_sort.blank?
 
       return model
     end

app/controllers/v1/learning_objects_controller.rb

@@ -39,7 +39,10 @@ class V1::LearningObjectsController < ApplicationController
   before_action :set_paper_trail_whodunnit, except: [:index, :show]
 
   def index
-    learning_objects = paginate policy_scope(LearningObject).includes(:tags, :publisher, :language, :license, :subjects, :educational_stages, :reviews).order(score: :desc)
+
+    learning_objects = policy_scope(LearningObject).includes(:tags, :publisher, :language, :license, :subjects, :educational_stages, :reviews)
+    learning_objects = learning_objects.order(score: :desc) if params[:sort].blank?
+    learning_objects = paginate learning_objects
     serializer = params[:obaa].nil? ? LearningObjectSerializer : LearningObjectObaaSerializer
     http_cache_forever do
       render json: learning_objects, each_serializer: serializer