Best way to get a single value from a DataTable?

Question

I have several static classes that contain tables like this:

using System;
using System.Data;
using System.Globalization;

public static class TableFoo
{
    private static readonly DataTable ItemTable;

    static TableFoo()
    {
        ItemTable = new DataTable("TableFoo") { Locale = CultureInfo.InvariantCulture };
        ItemTable.Columns.Add("Id", typeof(int));
        ItemTable.Columns["Id"].Unique = true;
        ItemTable.Columns.Add("Description", typeof(string));
        ItemTable.Columns.Add("Data1", typeof(int));
        ItemTable.Columns.Add("Data2", typeof(double));

        ItemTable.Rows.Add(0, "Item 1", 1, 1.0);
        ItemTable.Rows.Add(1, "Item 2", 1, 1.0);
        ItemTable.Rows.Add(2, "Item 3", 2, 0.75);
        ItemTable.Rows.Add(3, "Item 4", 4, 0.25);
        ItemTable.Rows.Add(4, "Item 5", 1, 1.0);
    }

    public static DataTable GetItemTable()
    {
        return ItemTable;
    }

    public static int Data1(int id)
    {
        DataRow[] dr = ItemTable.Select("Id = " + id);
        if (dr.Length == 0)
        {
            throw new ArgumentOutOfRangeException("id", "Out of range.");
        }

        return (int)dr[0]["Data1"];
    }

    public static double Data2(int id)
    {
        DataRow[] dr = ItemTable.Select("Id = " + id);
        if (dr.Length == 0)
        {
            throw new ArgumentOutOfRangeException("id", "Out of range.");
        }

        return (double)dr[0]["Data2"];
    }
}

Is there a better way to write Data1 or Data2 methods that return a single value from a single string that matches a given identifier?

Update # 1:

I created an extension method that seems pretty nice:

public static T FirstValue<T>(this DataTable datatable, int id, string fieldName)
{
    try
    {
        return datatable.Rows.OfType<DataRow>().Where(row => (int)row["Id"] == id).Select(row => (T)row[fieldName]).First();
    }
    catch
    {
        throw new ArgumentOutOfRangeException("id", "Out of range.");
    }
}

Then my Data1 method will look like this:

public static int Data1(int id)
{
    return ItemTable.FirstValue<int>(id, "Data1");
}

and Data2 becomes:

public static double Data2(int id)
{
    return ItemTable.FirstValue<double>(id, "Data2");
}

Thanks to all of your answers, but especially Anthony Pegram, who gave a very nice single line of LINQ and Lambda code.

Answer 1

Linq (to DataSets)? Linq Data1 Data2 , .

:

, , , ( IDE:)

DataTable itemTbl = GetItemTable().AsEnumerable();

double dt1 = ((From t In itemTbl Where t.Id = <your_id> Select t).First())["Data1"];

, Enumerable.

Answer 2

, . , , , - , , , , . , . , :

int intValue = TableFoo.FirstValueOrDefault<int32>(7);
decimal decValue = TableFoo.FirstValueOrDefault<decimal>(7);

:

string strValue = TableFoo.FirstValueOrDefault<string>(7);
int? nintValue = TableFoo.FirstValueOrDefault<int?>(7);

, , , , , . null, ("" ). , , . datarow ( ValueOrDefault), .

. VB, #, .

Public Shared Function FirstValueOrDefault(Of T) (ByVal Int ID) As T
    Dim r as datarow = ItemTable.Select("Id = " + id.ToString());
    If r.IsNull(0) Then
        If GetType(T) Is GetType(String) Then
            Return CType(CType("", Object), T)
        Else
            Return Nothing
        End If
    Else
        Try
            Return r.Field(Of T)(0)
        Catch ex As Exception
            Return CType(r.Item(0), T)
        End Try
    End If
End Function