google app engine: How do I add fields to an existent entity

Question

I have a google app engine app where I would like to extend one of my Entity definitions. How would I ensure existent entity objects get the new fields properly initialized? Would the existent objects, the next time I query them, simply have default values? I'd like to add a StringListProperty.

Answer 1

If you add a new property to your model, existing entities will have the default value for it when you load them, if you supplied a default. They won't show up in queries for that value until you fetch them and store them again, though.