[quietbritishjim]

That would just make the data loss problem worse still. I realise OP just chose an arbitrary example, but if you really are talking about users and orders, and if you delete a user, then really deleting the records for their associated orders is even worse than losing track of who made them.

[irrational]

I realize you might not be familiar with how database constraints work, but an on delete no action would totally prevent the user from being deleted. You literally cannot delete the user and their associated orders will definitely not be deleted.

[stouset]

GP did not suggest ON DELETE CASCADE.