1

app/models/shixun.rb

@@ -59,6 +59,9 @@ class Shixun < ApplicationRecord
   # Jupyter数据集,附件
   has_many :data_sets, ->{where(attachtype: 2)}, class_name: 'Attachment', as: :container, dependent: :destroy
 
+  # 试卷的实训题
+  has_many :exercise_questions
+
 	scope :search_by_name, ->(keyword) { where("name like ? or description like ? ",
 				"%#{keyword}%", "%#{keyword}%") }
 

app/services/subjects/data_statistic_service.rb

@@ -0,0 +1,22 @@
+class Subjects::DataStatisticService < ApplicationService
+  attr_reader :subject, :user
+  def initialize(subject, user)
+    @subject = subject
+    @user = user
+    @shixuns = subject.shixuns
+  end
+
+  # 学习总人数
+  def study_count
+    @shixuns.includes(:myshixuns).map{|shixun| shixun.myshixuns.pluck(:user_id)}.uniq
+  end
+
+  # 课堂学习人数
+  def course_study_count
+    # 实训作业
+    sw_user_ids = StudentWork.where.not(myshixun_id: nil).pluck(:user_id)
+    # 试卷的实训题
+    esa_user_ids = ExerciseShixunAnswer.where()
+  end
+
+end