Google App Engine Queries

Often, a model (table) needs to be queried to see if it’s empty or not. The fastest way to achieve this is …

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if len(User.all().fetch(1)) == 0
print 'No users'

if len(User.all().fetch(2)) == 1
print 'Only one user'

Use this method instead of User.all().count() when testing if any of a specific model exists. This should have better performance in cases where there are lots of the model (e.g. 1000+ Users) since count still needs to access each model in order to count it.