Refactor student_response_rate

app/models/student_response_rate.rb

@@ -6,9 +6,7 @@ class StudentResponseRate < ResponseRate
   private
 
   def survey_item_count
-    @student_survey_item_count ||= @subcategory.measures.map do |measure|
-      measure.student_survey_items.count
-    end.sum
+    @student_survey_item_count = SurveyItem.student_survey_items_for_measures(@subcategory.measures).count
   end
 
   def response_count

app/models/survey_item.rb

@@ -1,4 +1,11 @@
 class SurveyItem < ActiveRecord::Base
   belongs_to :measure
   has_many :survey_item_responses
+
+  scope :student_survey_items_for_measures, lambda { |measures|
+    joins(:measure).where(measure: measures).where("survey_item_id LIKE 's-%'")
+  }
+  scope :teacher_survey_items_for_measures, lambda { |measures|
+    joins(:measure).where(measure: measures).where("survey_item_id LIKE 't-%'")
+  }
 end

app/models/teacher_response_rate.rb

@@ -10,9 +10,7 @@ class TeacherResponseRate < ResponseRate
   end
 
   def survey_item_count
-    @teacher_survey_item_count ||= @subcategory.measures.map do |measure|
-      measure.teacher_survey_items.count
-    end.sum
+    @teacher_survey_item_count ||= SurveyItem.teacher_survey_items_for_measures(@subcategory.measures).count
   end
 
   def response_count