Re: Universal Astrological Database Format

From: programmer <>
Date: Wed, 23 Jul 2003 13:16:23 +0100
Message-ID: <bflupp$cqe$>

> When you are modelling your family tree you may need to cope with
> unusual relationships. I know of a case where a man married his
> step-daughter's daughter.

The modelling is simple, 2 entities are needed:

Person(PersonID, FatherID, MotherID, DetailsOfThePerson, ...)
primary key (PersonID)

Marriage(Date, HusbandID, WifeID, DivorceDate, DetailsOfTheMarriage, ...)
primary key (Date, HusbandID)
-- /* or primary key (Date, WifeID)*/
-- /* or primary key (Date, HusbandID, WifeID) if bigamy is allowed! */

For the case where the man(A) married his step-daughter's daughter(F).

PersonID, FatherID, MotherID
--------  --------  --------
A          null      null
B          null      null
C          null      null
D          C         B
E          null      null
F          E         D

Date      HusbandID    WifeID   DivorceDate
--------  ---------    ------   -----------
1/1/1950  C            B        1/1/1958
1/1/1960  A            B        1/1/1990
1/1/1970  E            D        null
1/1/1995  A            F        null

Writing a query to find such unusual relationships is a bit more difficult.
Received on Wed Jul 23 2003 - 14:16:23 CEST

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