Filling dropdownlist from DB - sql

Question

I'm trying to move over to MVC from webforms, and to be honest, it's not going very well.
I need a DropDownList populated with values from my database, and I'm having a hard time understanding how to do this.
I'm thinking, that I need to create a model,using entity framework, and refer my DropDownList to that? But how do I point it to that model?
Also, if I make a model, from a database table, how do I adjust the select command, so I only get certain values, and not the entire table?
I know this is kind of a broad question, and I have no examples listed, but I've had a really hard time, finding information I could understand, with regards to my issue.

Answer 1

I would start from this this should get you the project created if you have not done so so you can have the model ready
http://msdn.microsoft.com/en-us/data/gg685489
in order to create a dropdownlist here is an example
ViewBag.dropdownlist = new SelectList(db.tablename, "Valuefiled", "NameGField");
where Valuefiled=name of a column in your database that you want to use for values
"NameGField"=name of a column in your database that you want to use for names
getting drop down list to view
#Html.DropDownList("dropdownlist")

Answer 2

How About this
Your ViewModel
public class CategoryViewModel
{
public Category Category { get; set; }
public IEnumerable<SelectListItem> CategoryTitles { get; set; }
}
Your Controller
public ActionResult Create()
{
var categoryviewmodel = new CategoryViewModel();
categoryviewmodel.Category = new Category();
var list = categoryRepository.AllCategoryTitles().ToList().Select(t => new SelectListItem
{
Text = t.CategoryName,
Value = t.CategoryID.ToString()
})
.ToList();
list.Insert(0, new SelectListItem { Value = "0", Text = "Please Selext" });
categoryviewmodel.CategoryTitles = list;
return View(categoryviewmodel);
}
Your Repository
public IQueryable<Category> AllCategoryTitles()
{
var query = context.Categories.Where(m => m.ParentCategoryID == null && m.IsActive==true);
return query;
}
Your View
#Html.DropDownListFor(model => model.CategoryParentID, Model.CategoryTitles)

Answer 3

You can use a viewModel. Here is an example solution with some assumptions. Refer to the dropdownlist (here in the dropdown I am listing departments of type "InBound"
Employee Model
public class EmployeeModel
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public int DeptId { get; set; }
}
Department Model
public class DepartmentModel
{
public int Id { get; set; }
public string Name { get; set; }
public string Type { get; set; }
}
ViewModel (to be passed into the view)
public class EmployeeViewModel
{
public EmployeeModel Employee { get; set; }
public IEnumerable<DepartmentModel> Departments { get; set; }
}
Controller
public ActionResult Index()
{
EmployeeViewModel vm = new EmployeeViewModel();
//This is hardcoded. However you will write your own method to pull the department details with filtering
List<DepartmentModel> departments = new List<DepartmentModel>() { new DepartmentModel { Id = 1, Name = "Accounts", Type = "InBound" }, new DepartmentModel { Id = 2, Name = "Finance", Type = "OutBound" }, new DepartmentModel { Id = 3, Name = "HR", Type = "InBound" } };
vm.Departments = departments.Where(d => d.Type == "InBound");
return View(vm);
}
View
#model Test1.ViewModels.EmployeeViewModel
#{
ViewBag.Title = "Index";
}
<h2>Index</h2>
#using (Html.BeginForm())
{
#Html.HiddenFor(model => model.Employee.Id);
<table>
<tr>
<td>#Html.LabelFor(model => model.Employee.FirstName)</td>
<td>#Html.EditorFor(model => model.Employee.FirstName)</td>
</tr>
<tr>
<td>#Html.LabelFor(model => model.Employee.LastName)</td>
<td>#Html.EditorFor(model => model.Employee.LastName)</td>
</tr>
<tr>
<td>#Html.Label("Department")</td>
<td>#Html.DropDownListFor(model => model.Employee.DeptId, new SelectList(Model.Departments, "Id", "Name"))</td>
</tr>
</table>
}