Migrating objects in GAE data store with Java

I have an application that naturally as it grows various data model classes need to change attributes (add, rename, remove, etc). In MySQL I would just run a set of queries against the data store that would alter the schemas and the data.

I don't understand what is the correct approach to do with GAE's data store. My application on the server side is written in Java.

Specifically, I would like to know how to:

1) Rename a field on an exi开发者_如何学Pythonsting object 2) Add a new field on an existing object (I think this happen automatically on new objects)

Thanks for your help.

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You may want to consider using Objectify in managing the datastore; it also has the ability to update schemas of existing models quite easily.

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Someone has recently created a tool that would probably do what you need: http://code.google.com/p/entity-console/