OK still getting closer. My com interface works, but the SQL inside the dot net dll doesnt. Here is what I have so far that results in the error :

"Dynamic SQL generation for the UpdateCommand is not supported against a SelectCommand that does not return any key column information."

Does that mean the query has to return a Key column?

by the way the code in the previous post put the bytearray into the db , but it put it into a new row which isnt what i wanted. therefore I think the answer to the quedtion about key column above is no?

Code:
        Dim da As New SqlCeDataAdapter(strSQL, strCon)

        Dim ds As New DataSet()
        Dim cb As New SqlCeCommandBuilder(da)
        Dim row As DataRow

        da.Fill(ds)

        Dim arr() As Byte
        ReDim arr(FileLen(strSourceFile) - 1)
        FileOpen(1, strSourceFile, OpenMode.Binary, OpenAccess.Read, OpenShare.Shared)
        FileGet(1, arr)
        FileClose(1)

        

        ' row = ds.Tables(0).NewRow
        row = ds.Tables(0).Rows(0)
        row.Item(0) = arr
        ds.Tables(0).Rows(0).Item("myColumn") = arr
        da.Update(ds)