result= Booking.objects.filter()

方法一 .exists()

if result.exists():
print "QuerySet has Data"
else:
print "QuerySet is empty"

方法二 .count()==0

if result.count() == 0:
print "empty"

方法三

if result:
print "QuerySet has Data"
else:
print "QuerySet is empty"

总结：
QuerySet.exists() > QuerySet.count()==0 > QuerySet