def create_or_update(self, **kwargs):
"""
Similar to get_or_create, either updates a row or creates it.
The result will be (rows affected, False), if the row was not created,
or (instance, True) if the object is new.
"""
defaults = kwargs.pop("defaults", {})
# before locking attempt to fetch the instance
affected = self.filter(**kwargs).update(**defaults)
if affected:
return affected, False
lock_key = self.__make_key("lock", kwargs)
# instance not found, lets grab a lock and attempt to create it
with Lock(lock_key) as lock:
if lock.was_locked:
affected = self.filter(**kwargs).update(**defaults)
return affected, False
for k, v in defaults.iteritems():
if isinstance(v, ExpressionNode):
kwargs[k] = resolve_expression_node(self.model(), v)
return self.create(**kwargs), True
def create_or_update(self, **kwargs):
"""
Similar to get_or_create, either updates a row or creates it.
The result will be (rows affected, False), if the row was not created,
or (instance, True) if the object is new.
"""
defaults = kwargs.pop('defaults', {})
# before locking attempt to fetch the instance
affected = self.filter(**kwargs).update(**defaults)
if affected:
return affected, False
lock_key = self.__make_key('lock', kwargs)
# instance not found, lets grab a lock and attempt to create it
with Lock(lock_key) as lock:
if lock.was_locked:
affected = self.filter(**kwargs).update(**defaults)
return affected, False
for k, v in defaults.iteritems():
if isinstance(v, ExpressionNode):
kwargs[k] = resolve_expression_node(self.model(), v)
return self.create(**kwargs), True
def update(self, using=None, **kwargs):
"""
Updates specified attributes on the current instance.
"""
assert self.pk, "Cannot update an instance that has not yet been created."
using = using or router.db_for_write(self.__class__, instance=self)
for field in self._meta.fields:
if getattr(field, 'auto_now', False) and field.name not in kwargs:
kwargs[field.name] = field.pre_save(self, False)
affected = self.__class__._base_manager.using(using).filter(pk=self.pk).update(**kwargs)
for k, v in kwargs.iteritems():
if isinstance(v, ExpressionNode):
v = resolve_expression_node(self, v)
setattr(self, k, v)
if affected == 1:
signals.post_save.send(sender=self.__class__, instance=self, created=False)
return True
elif affected == 0:
return False
elif affected < 0:
raise ValueError("Somehow we have updated a negative amount of rows, you seem to have a problem with your db backend.")
else:
raise ValueError("Somehow we have updated multiple rows, and you are now royally f****d.")
def update(self, using=None, **kwargs):
"""
Updates specified attributes on the current instance.
"""
assert self.pk, "Cannot update an instance that has not yet been created."
using = using or router.db_for_write(self.__class__, instance=self)
for field in self._meta.fields:
if getattr(field, 'auto_now', False) and field.name not in kwargs:
kwargs[field.name] = field.pre_save(self, False)
affected = self.__class__._base_manager.using(using).filter(
pk=self.pk).update(**kwargs)
for k, v in kwargs.iteritems():
if isinstance(v, ExpressionNode):
v = resolve_expression_node(self, v)
setattr(self, k, v)
if affected == 1:
signals.post_save.send(sender=self.__class__,
instance=self,
created=False)
return True
elif affected == 0:
return False
elif affected < 0:
raise ValueError(
"Somehow we have updated a negative amount of rows, you seem to have a problem with your db backend."
)
else:
raise ValueError(
"Somehow we have updated multiple rows, and you are now royally f****d."
)
def create_or_update(model, using=None, **kwargs):
"""
Similar to get_or_create, either updates a row or creates it.
The result will be (rows affected, False), if the row was not created,
or (instance, True) if the object is new.
>>> create_or_update(MyModel, key='value', defaults={
>>> 'value': F('value') + 1,
>>> })
"""
defaults = kwargs.pop('defaults', {})
if not using:
using = router.db_for_write(model)
objects = model.objects.using(using)
affected = objects.filter(**kwargs).update(**defaults)
if affected:
return affected, False
create_kwargs = kwargs.copy()
inst = objects.model()
for k, v in defaults.iteritems():
if isinstance(v, ExpressionNode):
create_kwargs[k] = resolve_expression_node(inst, v)
else:
create_kwargs[k] = v
try:
return objects.create(**create_kwargs), True
except IntegrityError:
transaction.rollback_unless_managed(using=using)
affected = objects.filter(**kwargs).update(**defaults)
if not affected:
raise QueryError('No rows updated or created for kwargs: %r' % kwargs)
return affected, False
def create_or_update(model, using=None, **kwargs):
"""
Similar to get_or_create, either updates a row or creates it.
The result will be (rows affected, False), if the row was not created,
or (instance, True) if the object is new.
>>> create_or_update(MyModel, key='value', defaults={
>>> 'value': F('value') + 1,
>>> })
"""
defaults = kwargs.pop("defaults", {})
if not using:
using = router.db_for_write(model)
objects = model.objects.using(using)
affected = objects.filter(**kwargs).update(**defaults)
if affected:
return affected, False
create_kwargs = kwargs.copy()
inst = objects.model()
for k, v in defaults.iteritems():
if isinstance(v, ExpressionNode):
create_kwargs[k] = resolve_expression_node(inst, v)
else:
create_kwargs[k] = v
try:
return objects.create(**create_kwargs), True
except IntegrityError:
transaction.rollback_unless_managed(using=using)
affected = objects.filter(**kwargs).update(**defaults)
if not affected:
raise QueryError("No rows updated or created for kwargs: %r" % kwargs)
return affected, False
