HL7 FHIR advanced query

Question

We are looking at how to use FHIR over ReST apis to do more complex queries against a server w/ the patient data on it. The search parms on the URL as specified here: http://www.hl7.org/implement/standards/fhir/search.html gives basic operations and can do between dates,etc; But we need to do some nesting of "AND" and "OR" groupings of query criteria and are looking for an example of how to post an xml representation of such a query to the server and get the results back. Does that capability exist? And are there examples?

Thanks

Answer 1

There's no definition of advanced search functionality like this. The only support for this is to use a named query (_query=[name]), and associate parameters with your pre-defined variable names. Otherwise, you'll have to extend the API to define another operation.

Note: there is some interest in defining a more advanced search API than the simple one we currently define. But since the simple one turns out to be far from simple, there's not enough interest to drive the large amount of work involved in defining a really advanced query framework

Answer 2

We encountered the same requirement and are considering one of two options. 1. Use FHIR transactions that post bundles and receive bundled responses. 2. Extend the API by POSTing the query while specifying a ?_method=GET parameter to indicate that the HTTP POST should be handled as if it is a GET. We are leaning towards the latter.