Change IntegerProperty to FloatProperty of existing AppEngine DataStore

Question

I built an appengine application (python) which need to convert existing datastore entities in integer value (100) to float value (100.00) for currency conversion issue. How

Answer 1

Maybe a good way is to temporary create a new model:

class LearnTemp(search.SearchableModel):
    pid = db.ReferenceProperty(Product, collection_name='picks')
    title = db.StringProperty()
    description = db.TextProperty()
    order = db.IntegerProperty()
    order = db.IntegerProperty()
    cost = db.FloatProperty(default=0.000)
    cost1 = db.FloatProperty(default=0.000)

Then write some script, task or view which convert instances from old model to temporary model, converting the integer values to float. Make sure copying the id's and key's as well if somehow possible.

After change your main model and copy all entries from the temporary one to it. Then remove the temporary model.

This is most likely not the optimal way and requires some manual migration, though without South and on app engine I don't really see a good way to do it.