Getting an Entity By ID: Google Datastore (using Scala)

Here's another one of those, "it should be so simple" ones.

If you store an Entity in the Google Datastore, and you want to retrieve it by the auto-generated "Long" ID, none of the things you think would work...work.

SELECT * FROM mytype WHERE id = 12345, and so on...fail.

Note that the auto-generated column where the ID is put, is actually shown as "ID/Name" (but using that in any form doesn't help either).

You have to work with a Key (the below code assumes you have already created a new Query instance):

Note that I make sure I convert myVal to a Long (these two lines of code are actually in a "match", which via map iteration checks if the "v" in ( k, v ) is a Double, so I'm guarded against the exception you may have balked at), because when I send over the JSON from the UI, it appears as a Double on the server side, which won't work (and I tried everything short of getting into custom serialization).

Anyway, I banged around a couple of hours on this one, maybe it saves somebody some grief.

As always, thanks for visiting.