django: select_related() on an already-existing object?

Question

If I am retrieving an object with django, I can use .select_related() to instruct django to get all foreign key objects as well, to wit:

obj = ModelClass.objects.select_related().get(id=4) #1 db hit
foo = obj.long.chain.of.stuff #no db hit

If I already have obj, without it having been .select_related(), that is:

def doit(obj):
    obj.long.chain.of.stuff #4 db hits

is there any way to get django to fill in all of its foreign key relations? Something like:

def doit(obj):
    obj.magic() #1 db hit
    obj.long.chain.of.stuff #no db hits

Answer 1

I suppose I can do:

def doit(obj):
    obj = obj.__class__.objects.select_related().get(id=obj.id) #1 db hit
    obj.long.chain.of.stuff #no db hits

But is there any nicer way?