Merge branch 'dev_aliyun' of https://bdgit.educoder.net/Hjqreturn/educoder into dev_Ysm

db/migrate/20190815064542_modify_class_period_for_courses.rb

@@ -0,0 +1,8 @@
+class ModifyClassPeriodForCourses < ActiveRecord::Migration[5.2]
+  def change
+    Course.find_each do |c|
+      c.update_column(:class_period, c.class_period.to_i)
+    end
+    change_column :courses, :class_period, :integer
+  end
+end