New User - Discriminator confusion

Hi - here's what I'd like to do:

• Have an abstract base class of Animal
• Have abstract classes of Mammal and Fish inheriting from Animal with a Discriminator 'AnimalType'
• Have classes Cat and Dog inheriting from Mammal with a Discriminator 'MammalType'
• Have classes Sharks and Shrimps inheriting from Fish with a Discriminator 'FishType'

(I'm using the Single Table model, and I'm happy for all my 'Animals' to be in the same table.) But using separate Discriminators seems not to work - you have to have the same Discriminator through the chain of inheritance?

What would you recommend as a workaround? Because I need to be able to simply query for all Fish, or all Mammals, or more specifically for Dogs and Cats.

(I'm not really creating some animal kingdom taxonomy, it's just illustrative. Lightspeed 4.0.)

Can you elaborate on what is not working? I have set up a model here as you have described above and it appears to be working fine in that I can insert new entities and the correct discriminators are set at each level and then loading back the full set of Animals, Mammals or Fish correctly loads the derived types for each entity based on the two discriminators.

Jeremy

Sure, here are the steps:

• Create an abstract entity Animals, add an Entity Property 'AnimalType' of type Int32
• Create an abstract entity Mammals, add an Entity Property 'MammalType' of type Int32
• Create an entity Dog.
• Add an Inheritance Association from Mammals to Animals, set the Discriminator Name to 'AnimalType', the value to 1
• Add an Inheritance Association from Dog to Mammals, set the Discriminator Name to 'MammalType', the value to 2

Update the Db. The Table 'Animals' is created with columns Id, AnimalType, MammalType. That works okay.

In code, create and save a 'Dog'.

Now, what I would expect is that I have a row in my db table for my newly created Dog instance with AnimalType 1 (meaning a Mammal), and MammalType of 2 (meaning a Dog) - but the AnimalType is zero. (I also get a warning that Dog and Mammals are part of the same inheritance hierarchy, but have different discriminators.)

I'm not sure what or where I'm going wrong.

Thanks.

Thanks for the extra detail, I can see what you mean now. I have added in a candidate fix for this issue which will be available for you in the next nightly build. Let us know if this covers the issue for you.

Jeremy

Yes that has done the trick.

Thanks for the speedy response. I also had another query today which was quickly answered from the 'chat' thingy on your site - I must say I'm very impressed by the level of customer support Mindscape offers.

Thanks again.