Back to the Conceptual Data Model.
FACTS for the Data Model for a Genealogy Family Tree
The Approach :-
Establish the Business Rules or FACTS
The Facts define what is known about the 'Things of Interest' in the area being studied.
They establish an English-language version of the relationships between the 'Things of Interest'
which can be understood and agreed to by the key people such as Users.
This is very useful when the 'Things' become Entities or Tables in the Database.
The purpose of defining the Facts is to establish common understanding and agreement of the important
terms and concepts involved in Genealogy.
A note on Families :-
The Model has to allow for the concept of a family.
In other words, to define one family from another so that an individual can be a member of
more than one family, for example, step parents.
A. The Things of Interest are :-
B. Business Rules :-
B.1 Every INDIVIDUAL can be involved in zero or many RELATIONSHIPS.
B.2 Each INDIVIDUAL plays a ROLE in a RELATIONSHIP.
B.3 Every RELATIONSHIP involves two INDIVIDUALS.
C. Valid Relationships are :-
The Data Model supports an infinite number of RELATIONSHIPS,
which can be easily added to the RELATIONSHIPS Table as required.
D. Valid Roles are :-
The Data Model supports an infinite number of ROLES,
which can be easily added to the ROLES Table as required.