>I don't know about other back ends.

So far, I have adjusted my framework to support VFP, SQL Server, DBaseIV and SQL Anywhere. When I have to add a parameter, where I construct my SQL command, I can call a ParameterAddSQL() method which would add the proper syntax in the command such as:

        ' Add a parameter in the SQL with a proper syntax depending on the backend
        ' expC1 Field
        Public Function ParameterAddSQL(ByVal tcField As String) As String
            Dim lcString As String = ""

            ' Different backends handle it differently
            Select Case nBackend

                ' Visual FoxPro
                Case 1
                    lcString = "?"

                    ' SQL Server
                Case 2
                    lcString = "@" + tcField

                    ' SQL Anywhere
                Case 4
                    lcString = "?"

            End Select

            Return lcString
        End Function

An example would be:

            loDataProvider.ParameterAdd("Numero", oProcess.nNoMember, , "Member", "Numero")
            If Not loDataProvider.SQLExec("SELECT Member.NoType " + _
             "FROM Member " + _
             "WHERE Member.Numero=" + loDataProvider.ParameterAddSQL("Numero") ) Then
                Return False
            End If

I am still not sure however if I could change ParameterAddSQL() to adjust the string based on the type of connection instead such as:

        ' Add a parameter in the SQL with a proper syntax depending on the backend
        ' expC1 Field
        Public Function ParameterAddSQL(ByVal tcField As String) As String
            Dim lcString As String = ""

            ' Different SQL mode handle it differently
            Select Case nSQLMode

                ' OleDb
                Case 1
                    lcString = "?"

                    ' SQL client
                Case 2
                    lcString = "@" + tcField

                    ' ODBC
                Case 3
                    lcString = "?"

            End Select

            Return lcString
        End Function