make mapping polymorphism migration handle mapping problems

2016-01-06 10:23:01 +08:00 · 2016-01-06 10:23:01 +08:00 · 75d9339010
parent 21aba2fe5e
commit 75d9339010
1 changed files with 8 additions and 4 deletions
--- a/db/migrate/20151001024122_mapping_polymorphism.rb
+++ b/db/migrate/20151001024122_mapping_polymorphism.rb
@ -15,12 +15,16 @@ class MappingPolymorphism < ActiveRecord::Migration
      end

      unless mapping.synapse_id.nil?
-        mapping.mappable = Synapse.find(mapping.synapse_id)
+        mapping.mappable = Synapse.find_by(id: mapping.synapse_id)
      else
-        next if mapping.topic_id == 0
-        mapping.mappable = Topic.find(mapping.topic_id)
+        mapping.mappable = Topic.find_by(id: mapping.topic_id)
+      end
+      
+      if mapping.mappable.nil?
+        mapping.delete
+      else
+        mapping.save
      end
-      mapping.save
    end
  end