Thank you for choosing our components and services!
I would suggest you to consider reordering your phases, as if you start with the new web front end based an old and limited backend and API you can easily get in troubles with what is supported and what is not. Probably you will design you UI and services around those limitations which in the next phase would impose them to your SQL server, ORM and backend code. As a result after you complete the second phase your project could be less maintainable and less extensible. I would do it the other way around if possible - first proper design the database structures, the data migration if needed, then build the DataLayer, Services and UI.
Of course due to aggressive milestones this could not be possible. In such case I would try to wrap the legacy DataLayer with an abstraction that mimics the API of the ORM to be used so that later on it could be replaced more easy.
I would like also to point you to some important documents about Telerik Data Access
Fluent (code-only) mapping
Schema migration API
Low level ADO API
Handling OpenAccessContext in Web Projects
Hope this helps. Should you have any further questions do not hesitate to get back to us.
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