Re: Modeling heterogeneous entities (inheritance issue)

2008-07-10 Thread Mike Kienenberger
As Malcolm said, I wouldn't model this with inheritance. I've done something similar, probably using what Malcolm called Composition Design. I used a LOG table to track field-level changes in my application: ColumnName Type Name SizeScale NullableAutoIncrement Type

Modeling heterogeneous entities (inheritance issue)

2008-07-10 Thread ihawk ihawker
Thank you for the answer. As I understand I follow Composition Design, but still have problems with implementing inheritance... It seems my first message was badly formatted. So I'll copy it in this message again: - Hello! I am trying to model a list of heterogeneous entities b

Re: Modeling heterogeneous entities (inheritance issue)

2008-07-10 Thread Malcolm Edgar
For this type of design a couple of alternatives are: #1 - Composition Design Follow the object composition pattern, i.e. an object has a, instead of an object is a. So your base entity could maintain a type column and then foreign key relationships to other tables, dependent upon what type of en

Modeling heterogeneous entities (inheritance issue)

2008-07-10 Thread ihawk ihawker
Hello! I am trying to model a list of heterogeneous entities by having a ListItem table where the list item entity is able to point to an arbitrary entity (Person, Computer, URL, Movie, etc). I don't want to use single-table inheritance natively supported by Cayenne because of big database si