Re: Entity Relationship Modelling Problem for a Genealogy RDB

Guy Bourdon wrote:
>
> I've managed to model the following entities (events)
> for a genealogy database;

You might want to look at how this is all done in GEDCOM, the standard format for geneological data. Check out http://www.gendex.com/gedcom55/55gcch2.htm which lists the table and record relations for a GEDCOM database.

> 3rd - This blessed event may be certified by the state and/or sanctified
> by the church. How do you establish the right relationship to the
> proper location where the event(s) took place?

It would seem that a single UNION between two individuals could have multiple marriage events associated to it: one for each of 0 or more religious ceremonies, one for a each of 0 or more civil proceedings, one for each of 0 or more divorces. The UNION continues as a fact even after the divorce -- for example, if the couple had kids, the kids are the result of that union regardless of the legal status of the union at any given time.

Additionally you might have to have some way to record a common_law marriage union that is not marked by either religious or civil events. Merely finding such a union by looking for unions without either religious or civil marriage events wouldn't suffice -- the NULLS would indicate lack of knowledge about when or if there was an event, and would not consititute evidence that there was no such event.

-- 
Jeff