adding a dataset inside a datareader in vb.net - vb.net

Question

i hope i have asked the question title correctly. let me explain my issue -
i am making a table through vb.net code (htmltablecell, htmltablerow..) no this table populates with an sql query and works perfectly. but inside this table in one tablecell, i need to add a dropdownlist which shall require a completely differernt query and shall run on its own on each row. so the code is as follows
Sql = "..."
rd = ExecuteReader(SqlCnn, Sql)
Dim newcounter As Integer = 0
While rd.Read()
newcounter += 1
Dim tr As New HtmlTableRow
Dim td As New HtmlTableCell
Dim chkbox As New CheckBox
Dim id As String = rd("id") & ""
If id.Length = 0 Then id = "new" & newcounter
id &= "_" & rd("col1")
chkbox.Style.Add("width", "20%")
chkbox.ID = "new_id_" & id
chkbox.Text = rd("col1")
tr.Style.Add("width", "100%")
td.Style.Add("width", "10%")
td.Style.Add("text-align", "left")
td.Controls.Add(chkbox)
tr.Cells.Add(td)
td = New HtmlTableCell
td.Style.Add("width", "30%")
Dim ddl As New dropdownlist
ddl.Style.Add("width", "80%")
ddl.ID = "a1_" & id
--???????
td.Controls.Add(ddl)
tr.Cells.Add(td)
the ??? in the code is where the dropdownlist shall get populated each time with its own datareader and while loop and query. how can i achieve this?

Answer 1

I would do this with 2 queries; 1 to get the ddl data and 1 to get the actual records. Get the ddl data (ddlDataReader) before the actual results, create the ddl object and add it to each row.
Something like this should work: (I don't do VB.Net, so you may need to fix things)
Dim ddl As New dropdownlist
ddl.Style.Add("width", "80%")
ddl.ID = "a1_" & id
While ddlDataReader.Read()
---add items to ddl
end
Dim newcounter As Integer = 0
While rd.Read()
newcounter += 1
Dim tr As New HtmlTableRow
Dim td As New HtmlTableCell
Dim chkbox As New CheckBox
Dim id As String = rd("id") & ""
If id.Length = 0 Then id = "new" & newcounter
id &= "_" & rd("col1")
chkbox.Style.Add("width", "20%")
chkbox.ID = "new_id_" & id
chkbox.Text = rd("col1")
tr.Style.Add("width", "100%")
td.Style.Add("width", "10%")
td.Style.Add("text-align", "left")
td.Controls.Add(chkbox)
tr.Cells.Add(td)
td = New HtmlTableCell
td.Style.Add("width", "30%")
td.Controls.Add(ddl)
tr.Cells.Add(td)
Another approach would be to load the ddl data into a datatable, so that you can loop through it multiple times, and then create the ddl with a unique Id when each row is being created.