Hi Burke, I wasn't thinking of users.user_id though... >From what I understand is that when creating a patient, we want the underlying person to be created and hence that constraint from the changeset, but how do we ensure that the person_id won't collide with an existing person_id that was auto-generated for person table??
Or am I not understanding that constraint correctly?? Or did u mean that constraint is not required anymore and we can remove that changeset?? --- Regards, Saptarshi PURKAYASTHA My Tech Blog: http://sunnytalkstech.blogspot.com You Live by CHOICE, Not by CHANCE On 30 August 2011 07:24, Burke Mamlin <[email protected]> wrote: > When the person table was first introduced as a shared foundation for all > people in the system (we started with just patient & users), we made the > mistake of forcing the same ID across them (patient_id == person_id == > user_id). We since relaxed that, introducing patient.person_id and > users.person_id, so patient_id & user_id are no longer guaranteed/required > to be the same as the matching person_id. > > Lesson learned. > > -Burke > > On Mon, Aug 29, 2011 at 9:31 PM, Saptarshi Purkayastha > <[email protected]>wrote: > >> I was looking through the liquibase-schema-only.xml which creates the base >> schema for OpenMRS. >> >> Changeset 1227303685425-232 generates the following constraint: >> ALTER TABLE patient ADD CONSTRAINT person_id_for_patient FOREIGN KEY >> patient_id REFERENCES person.person_id ON UPDATE CASCADE >> >> I was left thinking how this has been working till now... patient_id is >> auto-increment and person_id is also auto-increment and both are primary >> keys of their respective tables viz. patient and person. Since we have an >> UPDATE CASCADE, a new patient_id will be sent as person_id... but how is >> that they will be able to generate the auto-incremented ids correctly?? >> >> How is it that primary key IDENTITY column is a FOREIGN KEY to another >> table's IDENTITY PRIMARY KEY column?? I'm confused how this works?? and >> isn't it logically incorrect?? >> >> --- >> Regards, >> Saptarshi PURKAYASTHA >> >> My Tech Blog: http://sunnytalkstech.blogspot.com >> You Live by CHOICE, Not by CHANCE >> ------------------------------ >> Click here to >> unsubscribe<[email protected]?body=SIGNOFF%20openmrs-devel-l>from >> OpenMRS Developers' mailing list > > > _________________________________________ To unsubscribe from OpenMRS Developers' mailing list, send an e-mail to [email protected] with "SIGNOFF openmrs-devel-l" in the body (not the subject) of your e-mail. [mailto:[email protected]?body=SIGNOFF%20openmrs-devel-l]
