CODEWITHSUNDEEP
c#sqlasp.net-mvcdistinct
user1300788
user1300788

Reputation: 181

asp.net 4.5 MVC SQL using distinct

@foreach (var item in Model) { string mytown = item.town.*enter distinct here* <option value="@mytown"> @mytown</option>

This selects all the town names in my database and I've got it to display in a drop down menu.

How can I change this so that when it's displaying the town names, it will only show each town name once.

For example, if I have 3 londons in the database it will show all 3 londons in the drop down menu. I want it to only show 1 london

FYI: Sorry this may seem like a repost but I posted the wrong code earlier

Upvotes: 1

Views: 8421

Answers (3)

RollerCosta
RollerCosta

Reputation: 5186

As far as my understanding, you can't do this if you are using ID as value.

Say 

ID | Value
1    Landon
2    Landon
3    Landon
4    Los Angeles

Better way you can achieve this is by using LINQ. Get the list from the database then filter it in the controller towns.Where(x => x.Name == x.Name.Distinct());

further Inside controller action

ViewBag.towns = new SelectList(towns.Where(x => x.Name == x.Name.Distinct()).ToList(), "Value", "Text");

Inside view

 @Html.DropDownListFor(x => x.SelectedTown, new SelectList(ViewBag.towns, "ID", "Name", Model.SelectedTown))

Upvotes: 1

Aniket Inge
Aniket Inge

Reputation: 25705

Why not convert it to a HashSet<string>()?

var hs = new HashSet<string>(Model);

given, Model is IEnumerable<string> ?

Or, do that in the controller, by converting the List<T> to HashSet<T> and then pass it as an IEnumerable<T> to the model.

or this one:

from y in Model.Distinct() select y

Upvotes: 0

maxspan
maxspan

Reputation: 14157

myCollection.Select(x => x.Name).Distinct().ToList();

Upvotes: 2

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