When new Attribute Added...

Hi, apologies if this is covered elsewhere but if a new attribute is added to an issue, is there a way to propagate this to existing issues already stored on the database.
The example I'm working on is a new attribute/field for Invoice Status. I've added it in but as I've a couple of months of issues on the database, I'd like to add a 'attr_values' record for this entry for all existing.
I could achieve with some sql work but just wondering if there's an easier way as it's likely to be a fairly common query.

Thanks.