Question

I am using Google App Engine with the Datastore interface.

Whenever I’m trying to update an entity, a whole new entity is created, this is despite the fact that I’m positive I am saving the same entity, meaning it has the same key for sure.

This is my code:

Key key=KeyFactory.createKey("user",Long.parseLong(ID));
DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
Entity entity=new Entity("user",key);
entity.setProperty // ...whatever, updating the properties
datastore.put(entity); //by putting an entity it's supposed to
// either create a new one if non exists, or update an entity if it already exists

I am sure that the key is the same during all updates as is confirmed in my admin console:

id=3001   600643316
id=3002   600643316
id=3003   600643316 

a bunch of entities with the same key (600643316) is created.

Answer 1

The datastore only lets the app create a new entity with a String key name, not a numeric ID. Numeric IDs are system-assigned IDs. If the Key has a numeric ID but not a String key name, then the datastore will ignore it and replace it with a system-assigned numeric ID.

In your example, if ID is a string, then you can just remove the Long.parseLong() bit, or convert it back to a String. KeyFactory.createKey(String kind, String name) creates a Key with a key name.