member_count问题

app/models/subject.rb

@@ -39,6 +39,10 @@ class Subject < ActiveRecord::Base
     count
   end
 
+  def member_count
+    self.shixuns.map(&:myshixuns_count).sum
+  end
+
   def subject_shixuns
     count = 0
     self.stage_shixuns.each do |stage_shixun|