CODEWITHSUNDEEP
google-app-enginegoogle-cloud-datastore
user2924127
user2924127

Reputation: 6240

Generating a unique id GAE datastore

In MySQL I used auto-increment to generate an id for every user. I would like to create a similar user table in Google Datastore where the id for a user will be unique. According to these docs:https://cloud.google.com/appengine/docs/java/datastore/entities

System-allocated ID values are guaranteed unique to the entity group.

But according to this post: Ever see duplicate IDs when using Google App Engine and ndb? the id's are not unique. I need this id to be unique. It is confusing because in the docs it says the id is unique, but from this post it says the id is not unique it is the key that is unique. My objective is for no two users to have the same id. How can I guarantee this? I would prefer for the database to take care of this form me opposed to me having to create large ids manually using things such as uuids.

Upvotes: 2

Views: 1038

Answers (1)

Andrei Volgin
Andrei Volgin

Reputation: 41089

As Igor correctly observed, IDs are always unique as long as the entity has no parent.

I can't think of any reason to make user entities children of some other entities, so you are safe.

Note that IDs will not be sequential, as it helps to spread the load equally across the entire dataset - it's a by-product of how the Datastore is designed.

Upvotes: 3

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