Function isEmptyFlightQuery

duckdbservice/flight_handler.go:1005–1013

isEmptyFlightQuery checks if a query is empty or contains only semicolons, whitespace, and/or comments. DuckDB rejects empty queries with SQLSTATE 42000, but PostgreSQL clients use these for pings (e.g., pgx sends "-- ping").

(query string)

	if tx == nil && isTxControl && execErr == nil {
		session.releaseSQLTransactionDrain()
	}
	if execErr != nil {
		if closedErr := sessionClosedStatus(execErr); closedErr != nil {
			return 0, closedErr
		}
		return 0, status.Errorf(codes.InvalidArgument, "failed to execute update: %v", execErr)
	}

	sendProfilingMetadataSince(ctx, execStartedAt)

	affected, err := result.RowsAffected()
	if err != nil {