Question

i have a problem in determining an object if it is empty or not…
here is my code :

this value has no data

>>> x = Booking.objects.filter(date_select='2011-12-3')
>>> print x
[]
>>> if x == None:
...  print 'none'
... 
>>> 

this has a data :

>>> x = Booking.objects.filter(date_select='2011-12-2')
>>> print x
[<Booking: arab>, <Booking: arab>, <Booking: vvv>]
>>> if x == None:
...  print 'none'
... 
>>>

I have learned that [] is not equal to None from my prev question…
Here is the algorithm that i want to apply in my code:

if x has an empty queryset
 print empy
else
 print data

can anyone can help me about it?
thanks…

Answer 1

Use exists()

Returns True if the QuerySet contains any results, and False if not.
This tries to perform the query in the simplest and fastest way
possible, but it does execute nearly the same query. This means that
calling QuerySet.exists() is faster than bool(some_query_set), but not
by a large degree.

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