Problem with entity framework with inheritance, condition, and foreign key.

Question

I just started to play around with Linq to entities and ran into an issue I can't figure out. I know this doesn't tell everything but to make it easier to understand here is a screen shot of the culprit...

I am getting this error:
Condition member 'RelatedResources.TypeID' with a condition other than 'IsNull=False' is mapped. Either remove the condition on RelatedResources.TypeID or remove it from the mapping.

The condition that exists is a TypeID field in the abstract entity RelatedResource that defines the type of RelatedResource(Book,Link,guide, ect...) TypeID is also a foreign key and is mapped in the association with the Resource Type entity. I think this is the problem but I don't know how or why I should change this.

Any ideas??? Thanks!!

Answer 1

Is RelatedResources.TypeID set to be not null (ie. 'Isnull=false') in the database and in the entityframework schema?

Not sure you can both have that field as a conditional and acts as a foreign key to another table.

And would you need to if you using the conditional inheritance to determine the type?

Answer 2

That usually happens when you have TypeID as a condition and also use it as a property. It might be causing problems because you are using it to map the association with ResourceType AND using it as a condition for the inheritance.