Re:Wolkenkit 3.0 – a CQRS and event-sourcing framework for J...
by kilburn on Tuesday December 18, 2018 @12:01PM
(#18708153)
> I think you're speaking more about event-sourcing than CQRS
True. I was reading to the comments here and yes, most of them were focusing on the Event Sourcing part of Wokenkit, not the CQRS so my mind got tricked.
Another problem with event sourcing is that there is no easily definable concept of a "field" that can be read from and written to using a named address (contrast with a SQL table column identifier). For a given aggregate, you'll have a single command service that writes a set of "fields" and an unbounded number of query services that receive a copy of that "field" from the event stream and can transform it in any imaginable way. Your "field" may be renamed and moved around through its journey from your command service's API request body to your event's serialized form and to your query service's internal data structures and its final resting place on the query service's persistence data store (mongodb or SQL table or whatever).
To identify a field, it's best to use its writable address, and you'll need to come up with your own identifier namespace and naming convention to represent those addresses.