Improved migration to work also with postgresql.

db/migrate/20170905140038_cti_log_preferences_migration.rb

@@ -1,6 +1,8 @@
 # Rails dropped the class
 # ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter::MysqlDateTime
 # via: https://github.com/rails/rails/commit/f1a0fa9e19b7e4ccaea191fc6cf0613880222ee7
+# ActiveRecord::ConnectionAdapters::PostgreSQL::OID::Integer
+# via: https://github.com/rails/rails/commit/aafee233fb3b4211ee0bfb1fca776c159bd1067e
 # which we use in stored Cti::Log instance preferences.
 # Since we don't need the instances but just an Hash we have to:
 # - create a dummy class
@@ -17,12 +19,23 @@ module ActiveRecord
     end
   end
 end
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID
+        class Integer < Type::Integer
+        end
+      end
+    end
+  end
+end
 
 class CtiLogPreferencesMigration < ActiveRecord::Migration[5.0]
 
   def change
     # correct all entries
-    Cti::Log.all.each do |item|
+    Cti::Log.all.pluck(:id).each do |item_id|
+      item = Cti::Log.find(item_id)
       next if !item.preferences
       next if item.preferences.blank?