I used JamSel to implement the SQL-like functionality. The selector is really a JMS selector but is quite effective on a FIX message. There is some good documentation

I've been looking at JamSel and it's very interesting. I assume you wrote some type of value adapter for QFJ messages. I'd like to borrow that if use JamSel in QFJ.

There is a simple interface to implement that calls you back to get the value of specific fields:

FIXMessageValueProvider.java

FIXMessage is just an interface that I wrap your QuickFIX messages in to minimise coupling.

You also need this to deal with identifiers such as $MsgType

FIXIdentifierExtension.java

It's that simple....