Based on your question and the additional comment you left it sounds like you're relatively new to MVC, as well as unfamiliar with Entity Framework? In that case I highly recommend the free Pluralsight videos available on http://www.asp.net/mvc
.
Check the links on the right sidebar, sounds like "Working with data part 1" is what you're after. They're great primers and will get you up and running quickly. Looks like the video's have been updated for VS2012 and MVC4, but if you're still on VS2010 and MVC3 they still have the older versions available here. Just click on the "Training from Pluralsight" link.
That said, if you have NuGet installed with VS you can add a quick reference to Entity Framework and have a code first context running real quick. If you add a connection string to your web.config and name it say ... "MyContext", then you could just add something like this to your project:
using System;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
namespace MyProject.CoolNameSpace
{
public class MyContext : DbContext
{
public DbSet<dd_data> DataEntities { get; set; }
}
public class dd_data
{
public string dd_name { get; set; }
public string dd_value { get; set; }
}
}
And you'll now have a working context. A lousy one, these classes should be in their files with proper namespaces and such ... but you get the idea.
From there you can work on attaching your model to your View, and to answer your original question I'd use a viewmodel that exposed one of your dd_data lists as a property, a single dd_value for a selected property, then use a DropdownFor to create your select list.
ViewModel:
public class MyViewModel
{
public List<dd_data> MyDataList { get; set; }
public string SelectedValue { get; set; }
}
Somewhere in the View:
@Html.DropDownListFor(m => m.SelectedValue, new SelectList(Model.MyDataList, "dd_name", "dd_value"))
Hopefully that'll get you started, but seriously watch those PluralSight video's, they're great. Cheers.