Yeah. This is another construction site we really need to start working on:
“Maps to value” is a makeshift solution. It allows splitting one concept into two for the MEASUREMENT and OBSERVATION EAV tables. Right now, it kind of works, but if you had more than a single split into two target concept pairs it would be undefined which “Maps to value” belongs to which “Maps to”. Also, we need to be able to split into other types, like (i) concept and number, (ii) concept and number and unit and (iii) concept and date. And who knows what else. the DRUG_STRENGTH table also is a similar construct, except it is not for mapping, but for reference. @Dymshyts and @rimma came up with a new relationship “Maps to numeric” to cover (ii).
I am thinking of a complex table CONCEPT_SPLIT or so. Thoughts?