Hi David,
I have added 2 child records to a Project which has no Parents , so after quering the Inv_hierarchies table found Last updated by as User A , now I have removed the child records with other user account B.
So in Inv_hierarchies table now the parent_id column is null as i have removed child records and Last updated as user .
Please correct me if my analysis is correct.
Thanks,
Santosh.