How can I implement String.Concat(object, object) to L2E framework?

Question

I have two long type columns that I want to concat during sql query. Using Linq to Entities making it impossible, because it only supports String.Concat(string, string).

I'd like to know how can I implement this function myself and add it to the L2E framework.

Answer 1

Can't you convert them to strings first, by doing String.Concat(long1.ToString(), long2.ToString())? Or is this not understood by the framework either?

Take a look at this question, which talks about some workarounds for this problem. Maybe you can adapt something to work here as well?

Answer 2

What's the point in doing the concat in SQL ? You can do it in a projection when you receive the data :

var query = from foo in db.Foo
            select new { foo.X, foo.Y };

var result = from foo in query.AsEnumerable()
             select foo.X.ToString() + foo.Y.ToString();

I'd like to know how can I implement this function myself and add it to the L2E framework.

I don't think that's possible, unless you want to implement your own EF provider...