Jira 7.5 JQL for finding sub-tasks of issues based on Epic-Link of parent

[Michael Ellis]

I have Epics with Stories linked by the Epic Link field, and these stories have sub-tasks.

We want to assign a component X to all Sub-tasks of issues with Epic Link A and a component Y to all Sub-tasks of issues with Epic Link B. 

There is a way to find all the issues and I've done that, but how can I then bulk change 1.5k Sub-Tasks to the correct component, X or Y? 

It seems like JQL lost some functions that would have been useful for doing this by version 7.5, our current version. Is there no way to do this now? 

[Andy Heinzer · Accepted solution]

With native Jira, there is not a simple way to find these in JQL at this time.

But with a 3rd party plugin, like scriptrunner, you could then gain access to a number of other JQL functions, such as subtasksOf.  This JQL query will allow you to find all the subtasks of a particular JQL query.   So for example, you could do something like:

issueFunction in subtasksOf("'Epic Link' = SCRUM-31")

This would return only the subtasks of issues returned by the query

'Epic Link' = SCRUM-31

I don't believe that Jira Server has ever had the JQL functions to be able to make this kind of search of subtask issues whose parents exist in an epic.