@Override
    public boolean wasNull() throws SQLException {
        ensureOpen();

        try {
            return currentRow != null && lastReadColumn > 0 && getColumns().get(lastReadColumn - 1).isNullable()
                    && currentRow.getValue(lastReadColumn - 1).isNullOrEmpty();
        } catch (Exception e) {
            throw SqlExceptionUtils.handle(e);
        }
    }
Check if there is another row.

@return {@code true} if this result set has another row after the current
        cursor position, {@code false} else
@throws SQLException if something goes wrong
clickhouse-jdbc/src/main/java/com/clickhouse/jdbc/ClickHouseResultSet.java