Question

My application is showing this error below:

Data binding directly to a store query (DbSet, DbQuery, DbSqlQuery) is not supported

Due to the fact that I am trying to bind my drop down control to this LINQ statement.
Check below for my code;

 using (AdventureWorksEntities dw = new AdventureWorksEntities())
        {
            ddlCon.DataSource = (from em in dw.Employees
                       select new { em.Title, em.EmployeeID }).Distinct().OrderBy(name => name);
            ;


            ddlCon.DataTextField = "Title";
            ddlCon.DataValueField = "EmployeeID";
            ddlCon.DataBind();
        }

NB: Please explain well in your answers why this error and the solution to it.

Answer 1

Just like in your other question, you need to use ToList(), as you can’t bind directly to a query result.

That being said, I also suspect your OrderBy is incorrect. This should likely be:

 ddlCon.DataSource = (from em in dw.Employees
                      select new { em.Title, em.EmployeeID })
                    .Distinct()
                    .OrderBy(emp => emp.Title)  // Pick Title or EmployeeID here
                    .ToList();