protected override object ReadNext() { int fieldSize = GetThisFieldCount(); if (fieldSize >= _messageSize) { AbandonShip(); } _nextFieldSize = null; // Check if this field is null if (fieldSize == -1) // Null value { return(DBNull.Value); } NpgsqlRowDescription.FieldData field_descr = FieldData; byte[] buffer = new byte[fieldSize]; PGUtil.CheckedStreamRead(Stream, buffer, 0, fieldSize); try { if (field_descr.FormatCode == FormatCode.Text) { return (NpgsqlTypesHelper.ConvertBackendStringToSystemType(field_descr.TypeInfo, buffer, field_descr.TypeSize, field_descr.TypeModifier)); } else { return (NpgsqlTypesHelper.ConvertBackendBytesToSystemType(field_descr.TypeInfo, buffer, fieldSize, field_descr.TypeModifier)); } } catch (InvalidCastException ice) { return(ice); } catch (Exception ex) { return(new InvalidCastException(ex.Message, ex)); } }
private void PrepareInternal() { // Use the extended query parsing... planName = m_Connector.NextPlanName(); String portalName = ""; preparedCommandText = GetCommandText(true); NpgsqlParse parse = new NpgsqlParse(planName, preparedCommandText, new Int32[] { }); NpgsqlDescribe statementDescribe = new NpgsqlDescribeStatement(planName); IEnumerable <IServerResponseObject> responseEnum; NpgsqlRowDescription returnRowDesc = null; // Write Parse, Describe, and Sync messages to the wire. m_Connector.Parse(parse); m_Connector.Describe(statementDescribe); m_Connector.Sync(); // Tell to mediator what command is being sent. m_Connector.Mediator.SetSqlSent(preparedCommandText, NpgsqlMediator.SQLSentType.Parse); // Flush and wait for response. responseEnum = m_Connector.ProcessBackendResponsesEnum(); // Look for a NpgsqlRowDescription in the responses, discarding everything else. foreach (IServerResponseObject response in responseEnum) { if (response is NpgsqlRowDescription) { returnRowDesc = (NpgsqlRowDescription)response; } else if (response is IDisposable) { (response as IDisposable).Dispose(); } } Int16[] resultFormatCodes; if (returnRowDesc != null) { resultFormatCodes = new Int16[returnRowDesc.NumFields]; for (int i = 0; i < returnRowDesc.NumFields; i++) { NpgsqlRowDescription.FieldData returnRowDescData = returnRowDesc[i]; if (returnRowDescData.TypeInfo != null) { // Binary format? // PG always defaults to text encoding. We can fix up the row description // here based on support for binary encoding. Once this is done, // there is no need to request another row description after Bind. returnRowDescData.FormatCode = returnRowDescData.TypeInfo.SupportsBinaryBackendData ? FormatCode.Binary : FormatCode.Text; resultFormatCodes[i] = (Int16)returnRowDescData.FormatCode; } else { // Text format (default). resultFormatCodes[i] = (Int16)FormatCode.Text; } } } else { resultFormatCodes = new Int16[] { 0 }; } // Save the row description for use with all future Executes. currentRowDescription = returnRowDesc; // The Bind and Execute message objects live through multiple Executes. // Only Bind changes at all between Executes, which is done in BindParameters(). bind = new NpgsqlBind(portalName, planName, new Int16[Parameters.Count], null, resultFormatCodes); execute = new NpgsqlExecute(portalName, 0); PrepareStatus = PrepareStatus.Prepared; }