where is eventstore projection documentation?

Question

Does anyone know of a comprehensive documentation on the projection API?

Also whats the difference between queries and projections within the eventstore ui?

Answer 1

As far as I understand a query in the UI is just an ad-hoc way to get an answer from your data, a projection on the other hand can be saved, read and will update itself when new events are received.

I think the documentation will be released when projections themselves are released (still in beta at the moment) - looks like they're coming in version 4 - https://groups.google.com/forum/m/#!topic/event-store/3Na4t3J_b2g

Answer 2

You are in luck. The version 4 is coming soon and since this is the first version where projections will be out of beta, the documentation is available. You can read it now at http://docs.geteventstore.com/projections/4.0.0/getting-started/