Inheritance in CDM/LDM models in PowerDesigner 15.3?

I downloaded PowerDesigner 15.3's trial version, and I want to build a Logical Data Model of a database. The problem is 开发者_如何学JAVAthat this database must use inheritance heavily, and I can't find a way to build an inheritance relationship... The 'Inheritance' button is in fact the only disabled button in the pallete, and I can't find a way to enable it... Did anyone else have this problem too? How can I enable it?

Thank you very much.

I can only guess that your model is using the Barker notation.

Try to select another notation in the Tools > Model Options dialog.

For example Choose E/R+Merise.

You'd better build a conceptual data model(CDM) first, and build the inheritance relationship in CDM.

After finished the CDM, you can select Tools>Generate Logical Data Model to genrate the LDM.

After adjust the LDM, you can select Tools>Generate Physical Data Model to genrate the PDM.

At last, select Database>Generate Database to generate SQL scripts.