Deeply Nested Aggregate query is not filtered by parent colum

[sftgoldie]

The query needs to count each occurance of a column value in a "history" table per each "definition" row. This requires looking up possible values and counting each of the possible "ExitReason Codes".

This query gets each subtask, but the count is the total count of each ExitReason, and not the ExitReason count for the give subtask:

query SubtaskExitReasonCount {
  ivr_subtasks {
    friendly_name
    subtask_histories {
      exitReasonByExitReason {
        exit_reason
        subtask_histories_aggregate {
          aggregate {  count  }
        }
      }
    }
  }
}

The following does work as expected; however, it would require filtering by each subtask_id rather depending on the implied relationships.

query SubtaskExitReasonCountWithFilter {
  ivr_subtasks {
    friendly_name
    subtask_histories {
      exitReasonByExitReason {
        exit_reason
        subtask_histories_aggregate(where: {subtask_id: {_eq: 1}}) {
          aggregate { count }
        }
      }
    }
  }
}

• How can the subtask_histories_aggregate be filtered/grouped by the subtask_id?
• Must this be done with a VIEW with an extra group by statement?
• Can a where clause reference a parent relationship property?

## Pseudo Code
subtask_histories_aggregate(where: {subtask_id: {_eq: "_root.id" }}) {
          aggregate { count }
        }

[tirumaraiselvan]

Similar: #5081