Fixed issue #1261 - Adding foreign keys for inconsistent PG tables breaks update.

db/migrate/20170531144425_foreign_keys.rb

@@ -1,4 +1,6 @@
 class ForeignKeys < ActiveRecord::Migration
+  disable_ddl_transaction!
+
   def change
 
     # return if it's a new setup
@@ -217,10 +219,12 @@ class ForeignKeys < ActiveRecord::Migration
     ]
 
     foreign_keys.each do |foreign_key|
-      begin
-        ActiveRecord::Migration.add_foreign_key(*foreign_key)
-      rescue => e
-        Rails.logger.error "Inconsistent data status detected while adding foreign key '#{foreign_key.inspect}': #{e.message}"
+      ActiveRecord::Base.transaction do
+        begin
+          add_foreign_key(*foreign_key)
+        rescue => e
+          Rails.logger.error "Inconsistent data status detected while adding foreign key '#{foreign_key.inspect}': #{e.message}"
+        end
       end
     end
   end