I am prototyping some new schema and am running into an issue with inheritance. The issue may stem from a limitation that I am not understanding properly. Is it possible to have multilevel inheritance using the Joined Inheritance Strategy? I have extended our Location entity (defined in our base project) in a new project which extends the base one. I need to extend this Ext Location entity but cannot seem to get it to work correctly. I noticed that I am unable to define the Inheritance Strategy type on the Ext Location in the extended project. I will outline what I am trying to do below:
Base Project Entity: Location (uses Joined strategy)
Extended Project Entity 1: ExtLocation (replaces parent, I cannot seem to select a strategy type for this entity as the option is greyed out in the designer)
Extended Project Entity 2: District (should extend ExtLocation using the Joined Strategy type)
Yes, it is possible to have multilevel inheritance using the Joined Inheritance Strategy.
In the designer of the Extended Entity 1 you should select your Base Entity in the “Parent” field. After that Inheritance Strategy Type will be selected automatically (this field will be greyed). Make sure that the field “Discriminator Value” is filled.
Now you can create Extended Entity 2 and select Extended Entity 1 as a parent. Inheritance Strategy Type will be selected automatically as well. And same as for Extended Entity 1 you have to fill “Discriminator value” field.
After these steps you can generate database scripts and check that new tables (for Extended Entity 1 and Extended Entity 2) contain only specific attributes and don’t contain attributes of the base entity.
If you have any issues with this flow, please provide more details such as a test project with reproducable errors, stack traces or any other information.