Question

I just have a hunch about this. But if feels like I’m doing it the wrong way. What I want to do is to have a db.StringProperty() as a unique identifier. I have a simple db.Model, with property name and file. If I add another entry with the same “name” as one already in the db.Model I want to update this.

As of know I look it up with:

template = Templates.all().filter('name = ', name)

Check if it’s one entry already:

if template.count() > 0:

Then add it or update it. But from what I’ve read .count() is every expensive in CPU usage.

Is there away to set the “name” property to be unique and the datastore will automatic update it or another better way to do this?

..fredrik

Answer 1

You can’t make a property unique in the App Engine datastore. What you can do instead is to specify a key name for your model, which is guaranteed to be unique – see the docs for details.