> After querying a data table into a DataRow array using DataTable.Select()
> method, is there any way of updating the table with changes made to the
> DataRow array?
>
> In this example, rows in the original data table do not change even when I
> change column values in the datarow array itself.
>
> Also, the following code creates an untyped data row array.  Is it possible
> to create a datarow array that's strongly typed based on the strongly typed
> datatable it's selected from?
>
> Thanks in advance,
>
> Andre Ranieri
>
>
> DataRow[] r = Class1.myDS.Categories.Select("", "CatOrder");
> for (int i =0; i < r.Length; i++)
>    {
>    lvCategories.Items.Add(r[i]["Category"].ToString().Trim());
>    r[i]["CatOrder"] = iCounter;
>    iCounter++;
>    }
> Class1.myDS.AcceptChanges();

"mabster" wrote:

> Andre,
>
> Unless I'm missing something, you code should work fine. I update the
> DataRow array returned from a DataTable.Select() call all the time, and
> the changes flow through to the original DataTable/DataSet.
>
> The rows returned from Select aren't copies - they're the actual rows in
> the original table.
>
> As for strongly-typed DataSets and DataRow arrays: Believe it or not,
> you can just cast the result from Select, like this:
>
>      MyDataSet.MyTableRow[] rows;
>
>      rows = (MyDataSet.MyTableRow[])ds.MyTable.Select(...);
>
> I was pleasantly surprised when I discovered that! :)
>
> Cheers,
> Matt
>
> Andre Ranieri wrote:
> > After querying a data table into a DataRow array using DataTable.Select()
> > method, is there any way of updating the table with changes made to the
> > DataRow array?
> >
> > In this example, rows in the original data table do not change even when I
> > change column values in the datarow array itself.
> >
> > Also, the following code creates an untyped data row array.  Is it possible
> > to create a datarow array that's strongly typed based on the strongly typed
> > datatable it's selected from?
> >
> > Thanks in advance,
> >
> > Andre Ranieri
> >
> >
> > DataRow[] r = Class1.myDS.Categories.Select("", "CatOrder");
> > for (int i =0; i < r.Length; i++)
> >    {
> >    lvCategories.Items.Add(r[i]["Category"].ToString().Trim());
> >    r[i]["CatOrder"] = iCounter;
> >    iCounter++;
> >    }
> > Class1.myDS.AcceptChanges();
>

"mabster" wrote:

> Andre Ranieri wrote:
>
> > Matt,
> >
> > I must be doing something wrong then.  When I step through the code block
> > the datarow array r[i]["CatOrder"] show the new value but the dataset
> > Class1.myDs.Categories[0]["CatOrder"] remains unchanged.  Any ideas?
>
> Perhaps the rows in your 'Categories' table aren't stored physically in
> CatOrder order?
>
> What I mean is: When you call Select to retrieve your "r" array of
> DataRows, you're asking for the array in CatOrder order.
>
> So when you edit r[0]["CatOrder"] you may not actually be changing
> Class1.myDs.Categories[0] ... you might be changing
> Class1.myDs.Categories[15] or something.
>
> Do you see what I mean?
>
> > As far as the strongly typed datarow is concerned, is this the right syntax?
> >  I'm getting a compile-time error  when I try your suggestion.  Intellisense
> > doesn't pick up Class1.myDS.CategoriesRows (my datatable name is Categories)
> > and the error says it denotes a field where a class was expected.
> >
> > Class1.myDS.CategoriesRows[] r = Class1.myDS.Categories.Select("",
> > "CatOrder");
> >
> > 'SenskePreNote.Class1.myDS' denotes a 'field' where a 'class' was expected
>
> Is "Class1" an actual object, or the name of a class? The error you are
> receiving tells me that something's wrong with the "Class1" identifier,
> not the casting of one type to the next.
>
> At any rate, the code should look more like this:
>
>      Class1.myDS.CategoriesRows[] r =
>         (Class1.myDS.CategoriesRows[])Class1.myDS.Categories.Select(
>              "", "CatOrder");
>
> (I've chucked some newlines in there so that the word wrapping doesn't
> make it too unreadable.)
>
> What I *think* is happening with your error is that "Class1" is actually
> a class, and you have to make an instance of it. Something along these
> lines:
>
>      Class1 cl = new Class1();
>
>      MyDataSet.CategoriesRows[] r = (MyDataSet.CategoriesRows[])
>          cl.myDs.Categories.Select("", "CatOrder");
>
> Does that look more correct?
>
> Cheers,
> Matt
>