Using multiple fields as value for the DropDownList control’s items

Using multiple fields as value for the DropDownList control’s items

Being an avid Access Programmer I have been frustrated with the limitation of VB DropDownLists to using only 1 field as the value. I found a way to simulate/work around this behavior with concatenation of several database fields at the query level to be my columns(i.e. Select KeyId1 + ‘~’ + KeyId2 + ‘~’ + KeyId3 as Keyval from…)

I use the combined keyval as the DropDown.DataValueField and then call my parse function after the user selects their choice on the DropDownList.SelectedItem.Value. I can now retrieve multiple column data from the DropDownList as I used to in Access without having to run an additional query. This may help other users that are frustrated with the limitations of the .NET combo/dropdownlist controls. In this particular application I have a series of nested dropdowns that depend on the selection of the previous dropdown.

This code is in the SelectedIndexChange event of the DropDownList1:

'(My Connection 'Cn' is already open)Dim mysql As Stringmysql = "select phaseid, description, PhaseID + '~' + RateHdrID + '~' + " _    & "BillStatus AS KeyVal from tblphase where tblphase.clientid = '" & _    Me.ClientCode.Text & "' and tblphase.jobid = '" & _    Me.DropDownList1.SelectedItem.Value & "' and = 1"Dim cmd2 As New SqlCommand(mysql, Cn)Dim drPhase As SqlDataReader = cmd2.ExecuteReader _    (CommandBehavior.CloseConnection)CboPhase.DataSource = drPhaseCboPhase.DataTextField = "phaseid"CboPhase.DataValueField = "KeyVal"CboPhase.DataBind()CboPhase.Items.Insert(0, "<---Select Phase-->")

After the postback on the CboPhase, in the SelectedIndexChange event I use this code:

If Me.CboPhase.SelectedIndex <> 0 Then    Me.RateHdrID.Text = ParseVal(Me.CboPhase.SelectedItem.Value, 2)    Me.BillStatus.Text = ParseVal(Me.CboPhase.SelectedItem.Value, 3)End If

Where the ParseVal function returns the n-th piece of the value string:

Public Function ParseVal(ByVal MyString, ByVal KeyPos) As String    ParseVal = ""    If MyString <> "" Then        Dim PosStart        Dim PosEnd        PosStart = InStr(1, MyString, "~")        If PosStart > 0 Then            Select Case KeyPos                Case 1                    ParseVal = Left(MyString, PosStart - 1)                Case 2                    PosEnd = InStr(PosStart + 1, MyString, "~")                    ParseVal = Mid(MyString, PosStart + 1, _                        PosEnd - PosStart - 1)                Case 3                    PosStart = InStr(PosStart + 1, MyString, "~")                    ParseVal = Mid(MyString, PosStart + 1)            End Select        End If    End IfEnd Function

See also  How HealthStream Learning Center Supports Healthcare Education and Compliance

About Our Editorial Process

At DevX, we’re dedicated to tech entrepreneurship. Our team closely follows industry shifts, new products, AI breakthroughs, technology trends, and funding announcements. Articles undergo thorough editing to ensure accuracy and clarity, reflecting DevX’s style and supporting entrepreneurs in the tech sphere.

See our full editorial policy.

About Our Journalist