How to bind LINQ data to dropdownlist

Question

The last two lines of this code do not work correctly -- the results are coming back from the LINQ query. I'm just not sure how to successfully bind the indicated columns in the results to the textfield and valuefield of the dropdownlist:

    protected void BindMarketCodes()
    {
        List<lkpMarketCode> mcodesList = new List<lkpMarketCode>();

        LINQOmniDataContext db = new LINQOmniDataContext();

        var mcodes = from p in db.lkpMarketCodes 
                        orderby 0
                        select p;

        mcodesList = mcodes.ToList<lkpMarketCode>();

        //bind to Country COde droplist
        dd2.DataSource = mcodesList;
        dd2.DataTextField = mcodesList[0].marketName;
        dd2.DataValueField = mcodesList[0].marketCodeID.ToString();

    }

score 33 · Answer 1 · answered Feb 20 '09 at 18:47

33

protected void BindMarketCodes()
{
    using(var dc = new LINQOmniDataContext())
    {
        dd2.DataSource = from p in db.lkpMarketCodes
                         orderby 0
                         select new {p.marketName, p.marketCodeID };
        dd2.DataTextField = "marketName";
        dd2.DataValueField = "marketCodeID";
        dd2.DataBind();
    }
}

// no need to use ToList()
// no need to use a temp list;
// using an anonymous type will limit the columns in your resulting SQL select
// make sure to wrap in a using block;

answered Feb 20 '09 at 18:47

andleer

22,388
8
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1

Thanks for adding this. I like your approach better, for the reasons that you outlined. – Jim G. Aug 12 '09 at 15:58
how to add attributes to dd2 in this way? – mmssaann Sep 10 '13 at 10:10
How would you reference this in a view? I am looking for a way to solve this exact issue. – Zach M. Oct 02 '13 at 14:48
Mine broke without ToList() – Mina Gabriel Jun 08 '16 at 18:46

score 29 · Accepted Answer · edited Jul 22 '15 at 22:40

29

See revised code below

protected void BindMarketCodes()
{    
    using (var dataContext = new LINQOmniDataContext()) {
        //bind to Country COde droplist
        dd2.DataSource = from p in dataContext.lkpMarketCodes 
            orderby p.marketName
            select new {p.marketCodeID, p.marketName};
        dd2.DataTextField = "marketName";
        dd2.DataValueField = "marketCodeID";
        dd2.DataBind();
    }
}

edited Jul 22 '15 at 22:40

Chase

9,289
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answered Feb 16 '09 at 21:38

James

12,636
12
67
104

2

couldn't get it work until I added dd2.DataBind(); as suggested by #Andrew_Robinson – openshac Jun 08 '11 at 16:07

score -3 · Answer 3 · answered Sep 06 '13 at 11:13

-3

DropDownList ddl_RouteLocation = (DropDownList)e.Row.FindControl("ddl_RouteLocation");   

ddl_RouteLocation.DataSource = dtLocation;--(dtlocation i have return method of linq in dtlocation)
ddl_RouteLocation.DataTextField =dtLocation.Rows[0]"LocationName"].ToString();
ddl_RouteLocation.DataValueField =dtLocation.Rows[0]["LocationId"].ToString();
ddl_RouteLocation.DataBind();
ddl_RouteLocation.Items.Insert(0, new ListItem("--Select--", "0"));

answered Sep 06 '13 at 11:13

Siddhartha Sengupta

1

This solution is too complex and can be realized more easy - see answer by andleer – Stefan Meyer Mar 19 '17 at 11:59

How to bind LINQ data to dropdownlist

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