CODEWITHSUNDEEP
sqloracle-databasedata-modeling
William R
William R

Reputation: 185

How to create inheritance on ORACLE Data Modeler

I am not able to crate an entity inheritance in Oracle SQL Data Modeler (v3.1, the most recent one).

Another issue: how to create a structured type?

Is someone can help? I have tried with Google and the help inside the software, I didn't found.

Upvotes: 3

Views: 1746

Answers (1)

cliffordheath
cliffordheath

Reputation: 2606

The best way is to create a subtype table whose primary key is a foreign key to the supertype table. Any new columns for the subtype get added to this table.

This pattern is known as "subtype separation". The other two patterns are subtype partition (copy the supertype fields into the subtype table and don't create a supertype record for subtype instances) and subtype absorption (add nullable subtype fields to the supertype table). Each pattern has cases where it is preferable.

Upvotes: 2

Related Questions