Question

This is what i’m trying to accomplish. I want to select only distinct values from all Rows in Column[0].

Then I want to get all the distinct values from column[2] and group them on column[0].

so basically i got a DataTable like so:

Fruit|Apples
Fruit|Pears
Vegetables|Peas
Vegetables|Carrots

so I want to do a foreach on the distinct values, so I would Enumerate Fruit once and then pick up Apples and Pears, and VegeTables once and pick up Peas and Carrots.

I’m doing this to create Accordion Panes, where I want to group my results under one header, the below code does such, however, it creates two panes of Fruit because it does not realize it already went though fruit.

 foreach (DataRow dtrow in dtTable.Rows)
        {
            string idRow = dtrow[0].ToString();
            AccordionPane currentPane = new AccordionPane();
            currentPane.ID = "AccordionPane" + Guid.NewGuid().ToString();
            currentPane.HeaderContainer.Controls.Add(new LiteralControl(dtrow[0].ToString()));
            foreach(DataRow dtRow2 in dtTable.Rows)
            {
                if(dtRow2[0].ToString() == idRow)
                {
                    currentPane.ContentContainer.Controls.Add(new LiteralControl(dtRow2[1].ToString()));
                }
            }
            NavigateAccordion.Panes.Add(currentPane);
        }

Answer 1

You can accomplish this easily when using linq, see for yourself:

var groupedRows = from row in dtTable.Rows.AsEnumerable()
                  group row by row[0] into grouped
                  select grouped;

foreach (var group in groupedRows)
{
    currentPane = new AccordionPane();
    currentPane.HeaderContainer.Controls.Add(group.Key.ToString());

    foreach (var row in group)
    {
        currentPane.ContentContainer.Controls.Add(row[1].ToString());
    }   
}

Or if you want to stick with your current non-linq approach:

foreach (DataRow dtrow in dtTable.Rows) 
        { 
            bool skip = false;

            foreach (var pane in NavigateAccordion.Panes)
            {
                if (pane.HeaderContainer.Controls[0].Text == dtRow[0].ToString())
                {
                    skip = true;
                    break;
                }
            }

            if (!skip)
            {
                string idRow = dtrow[0].ToString(); 
                AccordionPane currentPane = new AccordionPane(); 
                currentPane.ID = "AccordionPane" + Guid.NewGuid().ToString(); 
                currentPane.HeaderContainer.Controls.Add(new LiteralControl(dtrow[0].ToString())); 
                foreach(DataRow dtRow2 in dtTable.Rows) 
                { 
                    if(dtRow2[0].ToString() == idRow) 
                    { 
                        currentPane.ContentContainer.Controls.Add(new LiteralControl(dtRow2[1].ToString())); 
                    } 
                } 
                NavigateAccordion.Panes.Add(currentPane); 
            }
        }