Question

Does anyone know if its possible to create a new property on an existing Entity Type which is based on 2 other properties concatenated together?

E.g. My Person Entity Type has these fields ‘ID’, ‘Forename’, ‘Surname’, ‘DOB’

I want to create a new field called ‘Fullname’ which is

Forenames + ' ' + Surname 

So i end up with ‘ID’, ‘Forename’, ‘Surname’, ‘DOB’, ‘Fullname’.

I know i can do this using Linq programmatically i.e.

var results = from p in db.People select new {  ID = p.ID,  Forename = p.Forename,  Surname = p.Surname,  DOB = p.DOB, Fullname = p.Forename+ ' ' + p.Surname }; 

Then calling something like

var resultsAfterConcat = from q in results  where q.Fullname.Contains(value) select q; 

However i’d really like to use Linq to Entities to do this work for me at the Conceptual Model level.

Answer 1

Not yet, but maybe soon. First, note that your suggested query will not work at all in LINQ to Entities, with or without the property, because, at present, it doesn’t support Contains. The new version of the Entity Framework in .NET 4.0, however, is supposed to support custom methods in LINQ to Entities queries. You can see a video about this from PDC. Essentially, you have to write the custom method twice; once in code, and once on your database (e.g., in a calculated field). See the video for more information.