Toad World® Forums

Relationship Arc's


#1

Hi!

Is it possible with Toad Data Modeler to create relationship arc’s (exclusive or-relationships) in the logical model?

br
Mike


#2

Hi Mike,

Arc’s are not available in TDM. However, in TDM LER model you can create exclusive inheritances.

Double-click an inheritance | General tab | select the Exclusive checkbox.

I hope this will help.

Regards,

Vladka + TDM Team


#3

Thanks for your answer.

Unfortunately I can’t use this feature to design the following case:

A type has zero to many values.
A Item has zero to many values.
A Value relates eighter to a type or a item but never to both of them.

   **TYPE**                 **ITEM**          \                      /
       \                    /
        \                  /
       --o------------o--
           \             /
            A          A
              **VALUE

**How can I logically model this case using the TOAD Data Modeler, and generate the technical model out of the logical model?


#4

Just so you know (not trying to say you don’t need it), but arc’s are a non-standard modeling construct that Oracle Designer and the Barker Notation introduced. Also, Oracle Designer allows arc’s on both sides of the relationships - which make some scenario very difficult to have the database enforce either through constraints and/or triggers.

But I’ve asked for it before of the team - so maybe the product manager will ring in and get this for some future release. We could add arc support inside our current notations - so who knows :slight_smile:

Bert


#5

Thanks for your answer!

I will also send a feature request to the quest - data modeler developer team.


#6

No need - I am on the team. I work for Quest and help design what features go into our products (architect?) …