@Override
    public String format() {
        String formatName = name.trim();
        if (!formatName.contains(".")) {
            if (!formatName.startsWith("`")) {
                formatName = String.format("`%s", formatName);
            }
            if (!formatName.endsWith("`")) {
                formatName = String.format("%s`", formatName);
            }
        }
        if (StringUtils.isNotBlank(tableNameAlias)) {
            return String.format("%s.%s", tableNameAlias, formatName);
        }
        return formatName;
    }
It will be null if the field is a meta field
inlong-sort/sort-common/src/main/java/org/apache/inlong/sort/protocol/FieldInfo.java