Where clause with specific relation

REST
1

I have a table reports that has a 1:n relation with table periods (column name period) which has a 1:1 relation with table companies (column name company).
On my page I have a dynamic list that creates a table with all the reports where the periods company is XXX, using a where clause of period.company.objectId=‘xxxx-xxxx-xxxx’ which pulls through all reports where the company is XXX. I also need to get the details from the related period but if I add &loadRelations=periods (period.company.objectId=‘xxxx-xxxx-xxxx’&loadRelations=periods) then i get all related periods for a report, not just the one period child of the report and is the parent of the company.
I have been trying to use the having clause to pick out the right period but i’m struggling with it.

What I have:
image

What I get:
image
The report and all period relations where the company is Company B

What I need:
image
The report and period 2 relation where the company is Company B

Would this come under aggregation functions and the having clause?

2

How about requesting specific properties from periods through the property= query parameter instead of using loadRelations ?

3

I did not appreciate that the property query would isolate to the child relation in the chain in this way. Many thanks Mark, that will actually simplify a few of my api calls and logic within UI builder.