Question

I am stupidly new to VB.. I have my Class (dalv1) where all my functions are stored and my Main Form.

Code is as follows:

Public Sub getCustomerDetails()

        Try
            Dim cust_dataTable As New DataTable()
            Dim Connection As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & "Data Source = C:\Users\Public\Documents\VP - A1\Database\Database.mdb"
            Dim SQL As String = ("SELECT * FROM tblCustomers")
            Dim dataAdapter As New OleDbDataAdapter(SQL, Connection)
            dataAdapter.Fill(cust_dataTable)
            dataAdapter.Dispose()

        Catch ex As Exception
            MsgBox("ERROR : " & ex.Message.ToString)
        End Try

End Sub

I want to pass the DataTable, cust_dataTable to the Main Form so I can populate text boxes when the form loads.

Answer 1

You need to turn it into a function so that the table gets returned to the caller:

Public Function getCustomerDetails() As DataTable
  Dim cust_dataTable As New DataTable()
  Try
    Dim Connection As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & "Data Source = C:\Users\Public\Documents\VP - A1\Database\Database.mdb"
    Dim SQL As String = ("SELECT * FROM tblCustomers")
    Dim dataAdapter As New OleDbDataAdapter(SQL, Connection)
    dataAdapter.Fill(cust_dataTable)
    dataAdapter.Dispose()        
  Catch ex As Exception
    MsgBox("ERROR : " & ex.Message.ToString)
  End Try

  Return cust_dataTable
End Function

You didn’t share your form’s code, but here is an example of how you would call it:

Private da As New dalv1
Private _MyDataTable As DataTable

Protected Overrides Sub OnLoad(ByVal e As EventArgs)
  MyBase.OnLoad(e)
  _MyDataTable = da.getCustomerDetails
End Sub