[RESOLVED] Fill combobox depending on value of other combo

Hello,

I have 2 comboboxes.
When I choose a country in cboLand I want only the states to show in cboStaat that are associated with the country from cboLand.

I tried the code below but I get all different error messages.
Perhaps you can see something in my code that I missed.

Code:

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Public Sub SelectLand()
    Dim adapter As New OleDbDataAdapter("SELECT Land_ID,Land FROM tblLAND", connection)
    Dim table As New DataTable
    adapter.Fill(table)

    With Me.cboLand
      .DataSource = table
      .DisplayMember = "Land"
      .ValueMember = "Land_ID"
      .SelectedIndex = 0
    End With
  End Sub

    Public Sub SelectStaat()
        Dim adapter As New OleDbDataAdapter("SELECT Staat_ID,Staat FROM tblSTAAT WHERE Land_ID = " & Me.cboLand.SelectedItem, connection)
        Dim table As New DataTable
        adapter.Fill(table)


        With Me.cboStaat
            .DataSource = table
            .DisplayMember = "Staat"
            .ValueMember = "Staat_ID"
            .SelectedIndex = 0
        End With
    End Sub

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Thanks in advance

On which line is the error?
I think in the select statement the "Me.cboLand.SelectedItem" is wrong. it should be "CInt(Me.cboLand.SelectedValue)" if Land_ID type is integer.

Quote:

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Originally Posted by VBDT

On which line is the error?
I think in the select statement the "Me.cboLand.SelectedItem" is wrong. it should be "CInt(Me.cboLand.SelectedValue)" if Land_ID type is integer.

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Thanks for the quick reply.

When I use CInt(Me.cboLand.SelectedValue), the error is on line
Dim adapter As New OleDbDataAdapter("SELECT Staat_ID,Staat FROM tblSTAAT WHERE Land_ID = " & Me.cboLand.SelectedItem, connection)

The error reads: Conversion of type DataRowView to type integer is not valid.

I solved it using this code:

Code:

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Public Sub SelectLand()
    Dim adapter As New OleDbDataAdapter("SELECT Land_ID,Land FROM tblLAND", connection)
    Dim table As New DataTable
    adapter.Fill(table)

    With Me.cboLand
      .DataSource = table
      .DisplayMember = "Land"
      .ValueMember = "Land_ID"
            .SelectedIndex = 1
    End With
  End Sub

    Public Sub SelectStaat()
        Dim cmd As New OleDbCommand("SELECT Staat_ID,Land_ID,Staat FROM tblSTAAT WHERE Land_ID =?", connection)
        cmd.Parameters.Add(New OleDbParameter("Land_ID", OleDbType.VarChar))
        cmd.Parameters("Land_ID").Value = cboLand.SelectedValue.ToString
        Dim adapter As New OleDbDataAdapter(cmd)
        Dim table As New DataTable

        adapter.Fill(table)

        With Me.cboStaat
            .DataSource = table
            .DisplayMember = "Staat"
            .ValueMember = "Staat_ID"
            '.SelectedIndex = 1
        End With
    End Sub

    Private Sub cboLand_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cboLand.SelectedIndexChanged
        Me.txttest.Text = Me.cboLand.SelectedValue.ToString
        Call SelectStaat()

    End Sub
End Class

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