Re: Designer/2000 1.2: Super-sub-entity problem

Torsten.Manz_at_darmstadt.netsurf.de (Torsten Manz) wrote:

>I have a super-entity <A> with the sub-entities <A1> and <A2>. I know
>that Designer/2000 can build one, two and three table solutions from
>this. But how to get the three table solution? We got the one and the
>two table solution without problems, but prefere to have three tables.

You need to implement this as an *implicit sub-type* - to do this, do the following when you use the Database Design Wizard to map your entities to tables:

1. Set the "In Set?" checkbox for the super-type *AND* the sub-type entities.

The wizard will create one table for the super type, and one for each of the sub-types - each sub-type table will hold columns for every attribute in the sub-entity, and for every attribute in the super-type entity..

Hope that helps!

--
Simon Holt --  System Designer/DBA
** My opinions are not nescessarily those of my employers **
Britannia Zinc Ltd. Bristol, UK. (+44) 0117 982 3646