Your database includes the following stored procedure:
CREATE PROCEDURE dbo.GetNames
AS
SELECT CustomerID AS ID, RTRIM(LastName) + ', ' + FirstName AS Name
FROM Customers
When you generate an Entity Data Model from the database, you import this stored procedure. You need to modify the model to ensure that a method is added to the ObjectContext. The method must execute the stored procedure and return a type that represents the stored procedure result.
What should you do

Creating a function import in the conceptual model that maps to the stored procedure allows you to define a method on your ObjectContext that executes the stored procedure in the database. The second step is to map the result to a complex type.

When you work with EntityObject derived types, the object context manages the relationships between your objects, tracks changes as they occur, and supports lazy loading in the most efficient manner. For the given stored procedure result, an entity object is not needed.