Django serializer does unnecessary db queries

[anuraguniyal]

When django serializes object, to get the foreign key id referenced in object it queries the db instead of just using the id e.g.

class QBAccount(CompanyModel):
    company = models.ForeignKey(Company)

>>> from deretoapp.models import QBAccount
>>> import logging
>>> l = logging.getLogger('django.db.backends')
>>> l.setLevel(logging.DEBUG)
>>> l.addHandler(logging.StreamHandler())
>>> a = QBAccount.allobjects.all()[0]
>>> from django.core import serializers
>>> serializers.serialize('python', [a])
(0.000) SELECT `deretoapp_company`.`id`, ... FROM `deretoapp_company` WHERE `deretoapp_company`.`id` = 45995613-adeb-488f-9556-d69e856abe5f ; args=(u'45995613-adeb-488f-9556-d69e856abe5f',)
[{'pk': u'3de881eb-8409-4089-8de8-6e24f7281f37', 'model': u'deretoapp.qbaccount', 'fields': {... 'company': u'45995613-adeb-488f-9556-d69e856abe5f' ....}}]

Here db query after serializers.serialize is not needed because compay id could have been obtained directly by a.company_id, and query itself shows id is being passed to db to get the id, it looks like problem is because a.company.id is a db query which in ideal world also should not happen.

[Jannis Leidel]

In [17439]:

Fixed #17602 -- Stopped the XML serializer from doing unneeded queries. Thanks, gnosek.