Query recursion

Within the Choose and Book domain of the NHS CFH project, a requirement has been identified to allow dynamic recursion of queries. The topic was raised at the HL7 UK Infrastructure meeting on June 14th, 2006 and the consensus of those present at that meeting was that the current query mechanism is not sufficiently flexible to do what Choose and Book message designers need it to do.

File:Query Modelling Problem.ppt A presentation (available for download by clicking the link on the right) was given at the UK Infrastructure meeting, and includes a summary of the business requirements, an explanation of why we believe the current mechanism doesn't work, and our proposed solution - namely introducing the concepts of choice boxes and recursion to the query mechanism in order to dynamically process nested queries (examples are given in the presentation).

Comments/questions/suggestions on regarding this modelling problem are requested and would be gratefully received either here on the Wiki or via the message lists.