Method doExecute

src/dsql/DsqlRequests.cpp:574–702

Execute a dynamic SQL statement

// Execute a dynamic SQL statement
void DsqlDmlRequest::doExecute(thread_db* tdbb, jrd_tra** traHandle,
	IMessageMetadata* outMetadata, UCHAR* outMsg,
	bool singleton)
{
	firstRowFetched = false;
	const dsql_msg* message = dsqlStatement->getSendMsg();

	if (!message)
		JRD_start(tdbb, request, req_transaction);
	else
	{
		UCHAR* msgBuffer = req_msg_buffers[message->msg_buffer_number];
		JRD_start_and_send(tdbb, request, req_transaction, message->msg_number,
			message->msg_length, msgBuffer);
	}

	// Selectable execute block should get the "proc fetch" flag assigned,
	// which ensures that the savepoint stack is preserved while suspending
	if (dsqlStatement->getType() == DsqlStatement::TYPE_SELECT_BLOCK)
		request->req_flags |= req_proc_fetch;

	// TYPE_EXEC_BLOCK has no outputs so there are no out_msg
	// supplied from client side, but TYPE_EXEC_BLOCK requires
	// 2-byte message for EOS synchronization
	const bool isBlock = (dsqlStatement->getType() == DsqlStatement::TYPE_EXEC_BLOCK);

	message = dsqlStatement->getReceiveMsg();

	if (outMetadata == DELAYED_OUT_FORMAT)
	{
		needDelayedFormat = true;
		outMetadata = NULL;
	}

	if (outMetadata && message)
		parseMetadata(outMetadata, message->msg_parameters);

	if ((outMsg && message) || isBlock)
	{
		UCHAR temp_buffer[FB_DOUBLE_ALIGN * 2];
		dsql_msg temp_msg(*getDefaultMemoryPool());

		// Insure that the metadata for the message is parsed, regardless of
		// whether anything is found by the call to receive.

		UCHAR* msgBuffer = req_msg_buffers[message->msg_buffer_number];

		if (!outMetadata && isBlock)
		{
			message = &temp_msg;
			temp_msg.msg_number = 1;
			temp_msg.msg_length = 2;
			msgBuffer = FB_ALIGN(temp_buffer, FB_DOUBLE_ALIGN);
		}

		JRD_receive(tdbb, request, message->msg_number, message->msg_length, msgBuffer);

		if (outMsg)