Question Update database using column added at runtime

[dfenton21]

I have a question related to the one I posted at http://www.vbdotnetforums.com/ms-access/47948-update-database-using-dgv.html, but as it is a different question I thought it best to start a new thread.

I can update the database via the DGV perfectly when the DGV has the same columns as the database table.

I need to update a database field using a combobox column that I programatically add at run time. For the purposes of testing, I made a small application and database.

The database has one table called "Test" and 3 fields, NameId (key), FirstName, Result.

I populate the DGV with NameId and FirstName, and programatically add a combobox column called ResultList. I want to update the values in the Result field with the text selected in the comboboxes. However, I'm getting an error message when I run the SaveData function: "Parameter @Result has no default value". It seems to be unable to recognise that I've added the third column.

My code for the entire test application is as follows.

Imports System.Data.OleDb

Public Class Form1

Private connection As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Documents and Settings\Damien Fenton\Desktop\SQL Test.mdb;User Id=admin;Password=;")

 Private adapter As New OleDbDataAdapter("SELECT NameId, FirstName FROM Test", connection)

 Private table As New DataTable


 Private Sub InitialiseDataAdapter()


  Dim update As New OleDbCommand("UPDATE Test SET FirstName = @FName, Result = @Result WHERE NameId = @NameId", Me.connection)

  update.Parameters.Add("@FName", OleDbType.VarChar, 4, "FirstName")
  update.Parameters.Add("@Result", OleDbType.VarChar, 4, "ResultList")
  update.Parameters.Add("@NameId", OleDbType.Integer, 4, "NameId")

  Me.adapter.UpdateCommand = update

  Me.adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey


 End Sub

 Private Sub GetData()

  'Retrieve the data.

  Me.adapter.Fill(Me.table)

  DataGridView1.DataSource = table

  Dim NewColumn As New DataGridViewComboBoxColumn() 'Declare new DGV CC

  With NewColumn 'Set Properties
   .DataPropertyName = "ResultList" 'Name
   .HeaderText = "Result List" 'Heading
   .DropDownWidth = 160 'Width Of DropDown Box
   .Width = 90 'Display Width
   .MaxDropDownItems = 5 'How Many Items To Drop Down At A Time
   .ReadOnly = False
   .Items.Add("Attended") 'Add Some Text Items
   .Items.Add("Did not attend")
   .Items.Add("Left early")
   .Items.Add("Arrived Late")
  End With

  DataGridView1.Columns.Add(NewColumn) 'Add The Column



 End Sub

 Private Sub SaveData()

  InitialiseDataAdapter()

  Me.adapter.Update(Me.table)

  MsgBox("done")

 End Sub

 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

  GetData()

 End Sub

 Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

  SaveData()

 End Sub

End Class

Once again, any help will be greatly appreciated. Sadly, my lack of experience with the DGV control is an issue here.