[RESOLVED] Filling combo box with with a filter from a different combo box

[MikeDelke]

Hello,
I use Visual studio 2015, and Access 2016 and I am trying to fill a combo box with a select statement with a filter from another combo box.

Such as if combo box 1 contains State(AK) then In combo box 2 I want to show counties that are in that state (4)from the complete list of counties (3077). Don't want to show the Number I want to show the name of county. Yes the database is there and the table does have state(by 2 letter abrev. and the county by name) Here is the code for the State that works, and the County that doesn't :

Public Sub GetHState()

'Gets the State's to show in comboBox his state

Dim mcall = lblCall.Text
Dim ds As New DataSet
Dim dt As New DataTable
ds.Tables.Add(dt)
Dim da As New OleDbDataAdapter

'------------ FROM HERE THE NEXT LINES SET UP THE CONNECTION STRING FOR USER'S DATABASE------------------

Dim strFilePrefix = "NetControl"
Dim strFileSuffix = ".accdb"
Dim databaseFile As String = "C:\RRLogger Data\" & strFilePrefix & strFileSuffix
Dim conString = "Provider = Microsoft.Ace.OLEDB.12.0; Data Source= " & databaseFile

'--------------------------------------------------------------------------------------------------------------
con.ConnectionString = conString

con.Open()

da = New OleDbDataAdapter("Select State From State1", con) '

da.Fill(dt)

con.Close()


'CLEar combobox
cmbHState.Items.Clear()

'FILL COMBOBOX
For Each R As DataRow In dt.Rows
cmbHState.Items.Add(R("State"))

Next

'DISPLAY FIRST RECORD
cmbHState.Text = CType(dt.Rows(0).Item(0), String)


End Sub

Private Sub GetMCounty()

' Dim Access As New DbControl
'Dim mcall = lblCall.Text
Dim ds As New DataSet
Dim dt As New DataTable
ds.Tables.Add(dt)
Dim da As New OleDbDataAdapter

'------------ FROM HERE THE NEXT LINES SET UP THE CONNECTION STRING FOR USER'S DATABASE------------------

Dim strFilePrefix = "NetControl"
Dim strFileSuffix = ".accdb"
Dim databaseFile As String = "C:\RRLogger Data\" & strFilePrefix & strFileSuffix
Dim conString = "Provider = Microsoft.Ace.OLEDB.12.0; Data Source= " & databaseFile

'--------------------------------------------------------------------------------------------------------------
con.ConnectionString = conString

con.Open()

da = New OleDbDataAdapter("SELECT County FROM County WHERE State = cmbhState.Text", con)


da.Fill(dt)

con.Close()
'CLEar combobox
cmbMCounty.Items.Clear()

For Each R As DataRow In dt.Rows
cmbMCounty.Items.Add(R("County"))
Next

'DISPLAY FIRST RECORD



End Sub

When I run it I get the error...... Message "No value given for one or more required parameters." String

Please help?????

[OptionBase1]

da = New OleDbDataAdapter("SELECT County FROM County WHERE State = cmbhState.Text", con)

There may be more issues than this, but the above line is problematic for two reasons that I see.

The first is that if you want to use the value in cmbhState.Text rather than the literal string "cmbhState.Text", then cmbhState.Text needs to be outside of the quotes. The second is that, assuming State is not a numeric value, then you need to surround the search for value in quotes.

Addressing those issues should look something like this:

        da = New OleDbDataAdapter("SELECT County FROM County WHERE State = '" & cmbhState.Text & "'", con)

[MikeDelke]

Thank You for the Help.

That fixed the problem.