Add a button to export the search results in Django - Part 2

Refering to a previous post, it turns out that using str() to serialize the QuerySet query is not a viable solution if one of the selection criteria is a date. The str() will not quote the date value resulting in an invalid SQL statement.

Using pickle to serialize the query solves the problem.

# Replace str()
request.session['search_sql'] = str(Person.objects.filter(**kw).query)

# with pickle.dumps()
request.session['search_query'] = pickle.dumps(Person.objects.filter(**kw).query)

When the time comes to re-execute the query:

# Rather than executing a raw sql statement:
sql = request.session.get('search_sql')
object_list = Person.objects.raw(sql)

# deserialize the saved query and assign it to the QuerySet instead:
saved_query = request.session.get('search_query')
query = pickle.loads(saved_query)
object_list = Person.objects.all()
object_list.query = query

Although less secured, in order to store the query object in the request session, have to use the pickle based session serializer instead of the JSON based counterpart in Django 1.7.

=== settings.py ===
SESSION_SERIALIZER = 'django.contrib.sessions.serializers.PickleSerializer'