Modify A Google App Engine Entity Id?

I'm using Google App Engine NDB. Sometimes I will want to get all users with a phone number in a specified list. Using queries is extremely expensive for this, so I thought I'll ju

Solution 1:

The entity ID forms part of the primary key for the entity, so there's no way to change it. Changing it is identical to creating a new entity with the new key and deleting the old one - which is one thing you can do, if you want.

A better solution would be to create a PhoneNumber kind that provides a reference to the associated User, allowing you to do lookups with get operations, but not requiring every user to have exactly one phone number.