Just a short post to point out a ‘quirk’ in the FHIR syntax for querying so I can look it up again when I forget. (actually, it’s not really a quirk at all – it’s perfectly reasonable, though can be confusing).
It all came about when Josh pointed out an error in my post on retrieving documentReference resources from an server.
We were discussing how you could retrieve a filtered list of documentReference resources for a patient over a period of time, and used the example:
GET http://registryserver/DocumentReference?subject=100&period >=2013-01-01
However, as Josh pointed out – and as the spec indicates, you need an ‘=’ symbol in there to bind the HTTP parameter ‘period‘ to the value ‘>= 2013-01-01‘ which is what the FHIR server is going to query on. Thus the correct syntax is:
GET http://registryserver/DocumentReference?subject=100&period= >=2013-01-01
Now, if I had only tested the query out on one of the reference servers before I posted it, I would have avoided the error, but there you go…