Newbie just getting started with V4RB: Is-a relationships

[erne]

Hello,

on 28-02-2003 20:40, Ruslan Zasukhin at sunshine at public.kherson.ua wrote:

>> I am just getting started with Valentina for RealBasic, and I need to
>> clarify a couple of issues about hierarchical relationships in
>> Valentina before I get started with database design.
>> 
>> Say I have an object "Book"  with all the usual fields. It is a
>> subclass of VBaseObject. If I need to specialize Book into
>> "ManuscriptBook" (for example) can I subclass it and inherit all the
>> properties of Book? This is what some Object-relational RDMS  like
>> PostgreSQL allow.   But I'm not clear if Valentina allows it as well.
> 
> Right now no, but we definitely will,
> And in the way little different from Postgre.
> 

RB can however... 
it's not at Database engine level but useful indeed on app design

You can have the "Book" BO(Base Object)
and the "ManuscriptBook" BO that is a subclass of "Book"
and will inherit all its properties

This will work fine with the "Static" database model
(the one where you define all BOs as objects in memory)


Cool Runnings,
Erne.


-- 
|  e r  |  Ernesto Giannotta
|  n e  |  Musical Box - a media store