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I'm using Mongoid as my DB wrapper. I had a model with no inheritance and thousands of documents in the collection. I then refactored it to inherit from a base class. Now I can't retrieve the original data. I don't see it when querying the class or the base class.

How should I be handling this change? I see that Mongoid does allow inheritance and will store all the documents in the parent collection, then add a "_type" field for type differentiation. Should I migrate the data to a temp collection, deploy the code change and then migrate the temp data to the new base collection and set the _type field?

Thanks

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Decided to just do a dump of production to my local db. Then copy the documents to the new base class collection and verify the _type is set. Then finally restore it to production.

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How did you copy the documents to the new base class? –  cilphex Jul 16 '13 at 4:06
    
After you import the collection, check that it has a _type field. If not, you can set it with db.<collection>.update({ '_type': null }, { $set: { '_type': "<Ruby model class name>" } }, { multi: true }); Then finally copy them to the new base class collection with: db.<collection>.copyTo("<parent_collection>"); –  Malachor Jul 17 '13 at 14:16

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