迁移文件的调整

db/migrate/20190309085449_migrate_course_members.rb

@@ -19,15 +19,13 @@ class MigrateCourseMembers < ActiveRecord::Migration[5.2]
 
     ActiveRecord::Base.transaction do
       begin
-        Member.where("course_id != -1").find_each do |member|
-          if member.course && member.user
-            puts(member.id)
-            member.member_roles.each do |role|
-              course_member_role = role.role_id == 3 ? 1 : (role.role_id == 9 ? 2 : (role.role_id == 7 ? 3 : 4))
-              member_group_id = role.role_id == 10 ? member.course_group_id : 0
-              CourseMember.create!(course_id: member.course_id, user_id: member.user_id, course_group_id: member_group_id.to_i,
-                                   graduation_group_id: member.graduation_group_id.to_i, role: course_member_role, is_active: role.is_current)
-            end
+        Member.where("course_id != -1").includes(:member_roles).find_each(batch_size: 500) do |member|
+          puts(member.id)
+          member.member_roles.each do |role|
+            course_member_role = role.role_id == 3 ? 1 : (role.role_id == 9 ? 2 : (role.role_id == 7 ? 3 : 4))
+            member_group_id = role.role_id == 10 ? member.course_group_id : 0
+            CourseMember.create!(course_id: member.course_id, user_id: member.user_id, course_group_id: member_group_id,
+                                 graduation_group_id: member.graduation_group_id, role: course_member_role, is_active: role.is_current)
           end
         end
       rescue Exception => e