Rename field using Objectify and Google App Engine?
The simplest straight forward solution. Fetch all data with the annonation "AutoLoad()". Then store them again.In this way they will be saved as the new field.
The old one doesn't exist anymore or at least it doesn't contain any data anymore. It is like migrating the data from the old name to the new name. Anyone has better suggestions?
If you've changed the name of your field, you need to load and re-put all your data (using the mapreduce API would be one option here). There's no magic way around this - the data you've stored exists with two different names on disk.
Yeah exactly I guess this is the most convenient solution :) – Shady Aziz Mar 23 at 15:38.
AutoLoad is an API/Wrapper for @OldName :). They even have then same example. Check code.google.Com/p/objectify-appengine/wiki/… – Shady Aziz Mar 22 at 17:14.
I am trying a case where we changed a field name in our entity. According to objectify you have to use annonation @AutoLoad(""). This is ok and it works as Google Datastore doesn't delete the data Actually but it makes a new field so this annotation is like a mapping between the old and the new field.
No problem when you are reading the whole table. The problem arises when you apply a filter on your query (Suppose you made 5 objects with old name and 5 with new name). The result of your query depends on whether you used the old variable name or the new one (returns back only 5 but never the 10).
It won't fetch both of them and map them.
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