I'd like to ask for help for a problem I'm facing.
I'm designing an interface to input xml data into a database.
It deals with vendors.
Whenever I receive a business error from the database regarding a specific vendor (say vendor "A"), its data should be stored into a "rejected" storage.
If another update event about vendor "A" is received, it should wait for the first rejected one to be input, that means this event should also go to the rejected storage, and be processed after the solution of the problem with the first event.
Currently I'm thinking about storing these rejected events in a topic but I can't find out how to check the existance of a rejected event regarding vendor "A" in this topic.
I know this is a common issue. I'd like to know from you what solution you have used and select the one that better maches my needs and constraints.