My application is c# MVC5, using EF 6.1. Imported tables and functions using Database First. I can see the function in model (emdx) browser listed under DALModel.Store / Stored Procedures / Functions (grayed out).
I am trying to use the function using the following:
using (var ctx = new DALEntities())
int? result = ctx.fn_TotalClient(MemberRepository.AllowedCId, fromDate, toDate);
return (result != null ? result.Value : 0);
Apparently I could not use Scalar-Valued Function directly into my model; I found a solution in this blog http://programmaticponderings.wordpress.com/2012/11/22/first-impressions-of-database-first-development-with-entity-framework-5-in-visual-studio-2012/.
However, I used a different approach by redeveloping the function as a Table-Valued Function, then used FirstOrDefault() to get the result value.
Hope this could help someone facing the same issue.