EF + ODP.NET + CLOB = Value Cannot be Null - Parameter name: byteArray?

Question

Our project recently updated to the newer Oracle.ManagedDataAccess DLL\'s (v 4.121.2.0) and this error has been cropping up intermittently. We\'ve fixed it a few times with

Answer 1

We have this problem as well on some computers, and we are running the latest Oracle.ManagedDataAccess.dll (4.121.2.20150926 ODAC RELEASE 4).

We found a solution to our problem, and I just wanted to share.

This was our problem that occurred some computers.

Using connection As New OracleConnection(yourConnectionString)
    Dim command As New OracleCommand(yourQuery, connection)
    connection.Open()

    Using reader As OracleDataReader = command.ExecuteReader()
        Dim clobField As String = CStr(reader.Item("CLOB_FIELD"))
    End Using

    connection.Close()
End Using

And here's the solution that made it work on all computers.

Using connection As New OracleConnection(yourConnectionString)
    Dim command As New OracleCommand(yourQuery, connection)
    connection.Open()

    Using reader As OracleDataReader = command.ExecuteReader()
        Dim clobField As String = reader.GetOracleClob(0).Value
    End Using

    connection.Close()
End Using