移除实训的长类型的字段

db/migrate/20190622055449_modify_shixun_info_for_shixuns.rb

@@ -11,8 +11,5 @@ class ModifyShixunInfoForShixuns < ActiveRecord::Migration[5.2]
                            evaluate_script: shixun[:evaluate_script], shixun_id: shixun.id)
       end
     end
-    if Shixun.first.description.present?
-      remove_columns :shixuns, :description, :propaedeutics, :evaluate_script
-    end
   end
 end

db/migrate/20190622060005_remove_shixun_long_text_for_shixuns.rb

@@ -0,0 +1,7 @@
+class RemoveShixunLongTextForShixuns < ActiveRecord::Migration[5.2]
+  def change
+    if Shixun.first.description.present?
+      remove_columns :shixuns, :description, :propaedeutics, :evaluate_script
+    end
+  end
+end