damm | Damm algorithm functions , a check digit algorithm | Machine Learning library

I'm building a report that will catch all gaps and overlaps in the Responsible Start and End dates.

Idea is to have a column (Status), that will have 5 outputs (I understand, that there is a possibility of multiple scenarios for a record, but I need them to be assigned in the below order:

1. No Responsible - when no associated Responsible at all (ResponsibleId or ResponsibleName is NULL)
2. No Current Responsible - when across all the records associated with the Client, ResponsibleEndDate is not NULL (means current).
3. Overlap - when ResponsibleEndDate of the previous Responsible overlaps with ResponsibleStartDate of the following Responsible person.
4. Gap - when a gap between ResponsibleEndDate of the previous Responsible and ResponsibleStartDate of the following Responsible person.
5. Valid - when 1 day difference between ResponsibleEndDate of the previous responsible and ResponsibleStartDate of the following Responsible person.

I'm struggling with implementing sanity check where we use a variable

I am trying to make a page which pulls a bunch of data about users and then then displays (this part is fine). However I would like a condition within the fetch so that if there is nothing returned from the server a token or something can be set.

All I want is to have a condition that finds if the fetch statement actually contains any information (I am comfortable doing the rest)

Here is a code snippet describing what I am trying to do.