I understand that there is an on-going disagreement about this, but according to this CONCEPT_ID (to NULL or not to NULL) [THEMIS WG3], the final determination was that all concept_id fields should be filled with zero EXCEPT:
- MEASUREMENT.VALUE_AS_CONCEPT_ID
- MEASUREMENT.UNIT_CONCEPT_ID
- MEASUREMENT.OPERATOR_CONCEPT_ID
- OBSERVATION.VALUE_AS_CONCEPT_ID
- OBSERVATION.UNIT_CONCEPT_ID
I don’t really understand why these were specifically exempted when others were not.
Since the original post was about unit_concept_id, Christian’s answer matches my understanding, but I’m concerned it may be construed that all concept_ids can be NULLed.
I keep hearing conflicting information, and I thought the issue was settled.