id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
19360	annotate the sum of related TimeField	Luc Saffre	chrismedrela	"I get a ""TypeError: expected string or buffer"" when I try to annotate the sum of a timefield in a related model.
{{{
class Ticket(models.Model):  
    name = models.CharField(max_length=200)

class Session(models.Model):  
    ticket = models.ForeignKey(Ticket,related_name=""sessions"")
    time = models.TimeField()

qs = Ticket.objects.annotate(timesum=models.Sum('sessions__time'))
print [unicode(t.timesum) for t in qs]
}}}

Please see the attached files for a complete test case."	Bug	closed	Database layer (models, ORM)	dev	Normal	fixed		chrismedrela	Ready for checkin	1	0	0	0	0	0