This is part 2 of a series of posts discussing the particulars and as the title says, confusing bits of AQL. Part 1 is here. I’m hoping to discuss what choices implementers of clinical data query language designers have and the implications of such choices.
AND operator takes the stage
So let’s talk a bit more about the FROM clause, and the query semantics it may express. Let’s take the previous simple AQL query from part 1 and extend it a bit. First, the simplest form I used:
SELECT ... FROM EHR E CONTAINS COMPOSITION C CONTAINS ACTION A
Let’s assume that instead of the above query, our user is interested in fetching data related to a scenario in which a clinician observes some clinical condition, then instructs something. Our user is therefore looking for data that’ll be in a COMPOSITION that contains an OBSERVATION and an INSTRUCTION:. Apologies if you’re a clinical modeller and I just butchered my way through openEHR modelling, you’ll have to live with it for the moment.Read More »