迁移报错的实训

app/controllers/shixuns_controller.rb

@@ -1116,7 +1116,7 @@ class ShixunsController < ApplicationController
       apply_record = ApplyAction.where(:container_id => @shixun.id, :container_type => "ApplyShixun")
       apply_record.delete_all if apply_record
       HomeworkCommonsShixuns.where(:shixun_id => @shixun).delete_all # 关联删报错，后续解决
-      @shixun.destroy
+      @shixun.update_attribute(:status, -1)
       respond_to do |format|
         if params[:come_from] == "admin"
           format.html{ redirect_to shixuns_managements_path }

app/models/shixun.rb

@@ -73,7 +73,7 @@ class Shixun < ActiveRecord::Base
   end
 
   def fork_identifier
-    self.fork_from.nil? ? "--" : Shixun.find(self.fork_from).try(:identifier)
+    self.fork_from.nil? ? "--" : Shixun.where(id: self.fork_from).first.try(:identifier)
   end
 
   def get_fork

db/migrate/20190401011345_modify_fork_from_for_shixuns.rb

@@ -0,0 +1,11 @@
+class ModifyForkFromForShixuns < ActiveRecord::Migration
+  def up
+    shixuns = Shixun.where(:fork_from => 1933)
+    shixuns.each do |shixun|
+      shixun.update_attribute(:fork_from, nil)
+    end
+  end
+
+  def down
+  end
+end