How to use lookup processor to compare NULL Value？

[#1]

I have chain of look up processors.

Suppose I have a flowfile where the lookup key is a null value, and I intend to retrieve a corresponding value from a MySQL table. However, I consistently encounter an issue where the lookup process returns unmatched results, even when there are null values present in the MySQL table.

For instance, the 'filing_status_ID' field contains null values. When attempting to compare it with specific columns in the MySQL table, where the comparison value is also null, the outcome consistently registers as unmatched.

what can I do so that there will be match case? Like flowfile.key = mysqltable.key return match (NULL = NULL)

[#2]

Can anyone help this?

[#3]

This is the exactly problem I was facing, still no idea how it can be done.