Parent - children versions in Jira - oracle sql query needed

Question

We have created versions (parent/children) and we need to know how to get them from the database (oracle sql query). I managed to get all versions for one issue, but I don't have the hierarchy between the versions.  We do have the version v5.2.4 of jira

Harriche · Answer

In the planning board, i create a verdion v1 and a v2. In the version v2 i set v1 as a parent.

Timothy · Answer

We have created versions (parent/children)

How did you actually implement this "parent/child" in JIRA?