Hi.

It's actually a high-level architectural question.

Download Interbase and Firebird Developr Magezine issues 2 and 3 from
www.ibdeveloper.com and read "Object-Oriented Development in RDBMS".
And visit www.ambysoft.com and read about Object-relational mapping
(in Articles section).

Ther are several models and what to use heavily depends on the
particular application, framework, etc.

If you are not comfortable with SQL consider ORM packs like ECO for
Delphi (included in Enterprise and Architect versions) or Hibernate
for Java and .NET.

Maxim.