Public Class RoomInfo

    Dim ValTx As String
    Dim ValNr As Integer

Private Sub cboRoomType_DropDown(sender As System.Object, e As System.EventArgs) Handles cboRoomType.DropDown
        cboRoomType.Items.Clear()
        qry = "select RoomType from tblRoomType"
        cmd = New OleDb.OleDbCommand(qry, con)
        dr = cmd.ExecuteReader

        While dr.Read
            cboRoomType.Items.Add(dr("RoomType"))
        End While
    End Sub
    Private Sub cboRoomType_SelectValueChanged(sender As Object, e As System.EventArgs) Handles cboRoomType.SelectedValueChanged
        ValTx = cboRoomType.Text
        qry = "select RoomType from tblRoomType where RoomType = '" & ValTx & "'"

        cmd = New OleDb.OleDbCommand(qry, con)
        dr = cmd.ExecuteReader

        If dr.Read Then
            ValTx = dr("RoomType")
        End If
    End Sub

    Private Sub btnNext_Click(sender As System.Object, e As System.EventArgs) Handles btnNext.Click
        qry = "Insert into tblCheckIn (Guest_ID, GRoomType, GRoomNo, GRoomID, GRoomAmount, CheckInDate, Days, ChecOutDate) values ('" &
            txtGuestID.Text & "','" &
            ValTx &
            txtRoomNo.Text & "','" &
            txtRoomId.Text & "','" &
            txtRAmount.Text & "','" &
            dtpCheckIn.Value &
            txtDays.Text & "','" &
            dtpCheckOut.Value & "')"

        cmd = New OleDb.OleDbCommand(qry, con)
        dr = cmd.ExecuteReader()

        MsgBox("Successfully added in the database")
    End Sub

Ich weiß nicht, was das Problem hier ist. Ich denke, es ist das Kombinationsfeld, der ausgewählte Wert im Kombinationsfeld sollte in der Datenbank hinzugefügt werden. Was ist der richtige Wert für diese Combobox? Kann mir jemand helfen