Sure, I would like to be able to specify which columns I use at runtime rather than hardcoding which columns should be in the select.
With this specific use I have 3 potentially different sets of fields that will be required for any particular entity (List, Email (some extra columns beyond the list) and Admin Email (possibly more columns still if the user is an admin user)).
Further to that I am hoping to unify specific web apis into a small number of controllers with the field sets coming from elsewhere in the code - on a different model.
Company Model
List Fields
Email Fields
AdminEmail Fields
DTO Model Reference
etc
When the controller is called it will be called with the model and from that it will be able to dynamically add in the various extra info.
This will allow me to make a very DRY system (I hope) and after it is complete maintenance of the API shoul - I hope - be dead easy.