I am afraid that such scenario is not supported by OpenAccess ORM. You could have only one discriminator column in a table and this column should not be mapped to a property. Also OpenAccess handled automatically discriminator column, so the column couldn't be handled manually.
As a workaround I could recommend you to use two columns that are mapped to properties and set their values in the class constructor.
Currently we are not scheduled any changes for the discriminator column behavior in our backlog, that is why I advise you to post a feature request in our Ideas and Feedback Portal
, so other users can also see it and vote for it. Once it gathers votes from the community, we are going to prioritize it accordingly and schedule it for implementation.
If you have any further questions, do not hesitate to contact us again.
the Telerik team