def save(self, force_insert=False, force_update=False, using=None, update_fields=None):
"""
Saves the current instance. Override this in a subclass if you want to
control the saving process.
The 'force_insert' and 'force_update' parameters can be used to insist
that the "save" must be an SQL insert or update (or equivalent for
non-SQL backends), respectively. Normally, they should not be set.
"""
using = using or router.db_for_write(self.__class__, instance=self)
if force_insert and (force_update or update_fields):
raise ValueError("Cannot force both insert and updating in model saving.")
if update_fields is not None:
# If update_fields is empty, skip the save. We do also check for
# no-op saves later on for inheritance cases. This bailout is
# still needed for skipping signal sending.
if len(update_fields) == 0:
return
update_fields = frozenset(update_fields)
field_names = set()
for field in self._meta.fields:
if not field.primary_key:
field_names.add(field.name)
if field.name != field.attname:
field_names.add(field.attname)
non_model_fields = update_fields.difference(field_names)
if non_model_fields:
raise ValueError(
"The following fields do not exist in this "
"model or are m2m fields: %s" % ", ".join(non_model_fields)
)
# If saving to the same database, and this model is deferred, then
# automatically do a "update_fields" save on the loaded fields.
elif not force_insert and self._deferred and using == self._state.db:
field_names = set()
for field in self._meta.fields:
if not field.primary_key and not hasattr(field, "through"):
field_names.add(field.attname)
deferred_fields = [
f.attname
for f in self._meta.fields
if f.attname not in self.__dict__ and isinstance(self.__class__.__dict__[f.attname], DeferredAttribute)
]
loaded_fields = field_names.difference(deferred_fields)
if loaded_fields:
update_fields = frozenset(loaded_fields)
self.save_base(using=using, force_insert=force_insert, force_update=force_update, update_fields=update_fields)
def delete(self, key, version=None):
key = self.make_key(key, version=version)
self.validate_key(key)
db = router.db_for_write(self.cache_model_class)
table = connections[db].ops.quote_name(self._table)
cursor = connections[db].cursor()
cursor.execute("DELETE FROM %s WHERE cache_key = %%s" % table, [key])
transaction.commit_unless_managed(using=db)
def delete(self, using=None):
using = using or router.db_for_write(self.__class__, instance=self)
assert self._get_pk_val() is not None, "%s object can't be deleted because its %s attribute is set to None." % (
self._meta.object_name,
self._meta.pk.attname,
)
collector = Collector(using=using)
collector.collect([self])
collector.delete()
def save(self, must_create=False):
"""
Saves the current session data to the database. If 'must_create' is
True, a database error will be raised if the saving operation doesn't
create a *new* entry (as opposed to possibly updating an existing
entry).
"""
obj = Session(
session_key=self._get_or_create_session_key(),
session_data=self.encode(self._get_session(no_load=must_create)),
expire_date=self.get_expiry_date(),
)
using = router.db_for_write(Session, instance=obj)
sid = transaction.savepoint(using=using)
try:
obj.save(force_insert=must_create, using=using)
except IntegrityError:
if must_create:
transaction.savepoint_rollback(sid, using=using)
raise CreateError
raise
def _base_set(self, mode, key, value, timeout=None):
if timeout is None:
timeout = self.default_timeout
db = router.db_for_write(self.cache_model_class)
table = connections[db].ops.quote_name(self._table)
cursor = connections[db].cursor()
cursor.execute("SELECT COUNT(*) FROM %s" % table)
num = cursor.fetchone()[0]
now = timezone.now()
now = now.replace(microsecond=0)
if settings.USE_TZ:
exp = datetime.utcfromtimestamp(time.time() + timeout)
else:
exp = datetime.fromtimestamp(time.time() + timeout)
exp = exp.replace(microsecond=0)
if num > self._max_entries:
self._cull(db, cursor, now)
pickled = pickle.dumps(value, pickle.HIGHEST_PROTOCOL)
encoded = base64.b64encode(pickled).strip()
cursor.execute("SELECT cache_key, expires FROM %s "
"WHERE cache_key = %%s" % table, [key])
try:
result = cursor.fetchone()
if result and (mode == 'set' or
(mode == 'add' and result[1] < now)):
cursor.execute("UPDATE %s SET value = %%s, expires = %%s "
"WHERE cache_key = %%s" % table,
[encoded, connections[db].ops.value_to_db_datetime(exp), key])
else:
cursor.execute("INSERT INTO %s (cache_key, value, expires) "
"VALUES (%%s, %%s, %%s)" % table,
[key, encoded, connections[db].ops.value_to_db_datetime(exp)])
except DatabaseError:
# To be threadsafe, updates/inserts are allowed to fail silently
transaction.rollback_unless_managed(using=db)
return False
else:
transaction.commit_unless_managed(using=db)
return True
def get(self, key, default=None, version=None):
key = self.make_key(key, version=version)
self.validate_key(key)
db = router.db_for_read(self.cache_model_class)
table = connections[db].ops.quote_name(self._table)
cursor = connections[db].cursor()
cursor.execute("SELECT cache_key, value, expires FROM %s "
"WHERE cache_key = %%s" % table, [key])
row = cursor.fetchone()
if row is None:
return default
now = timezone.now()
if row[2] < now:
db = router.db_for_write(self.cache_model_class)
cursor = connections[db].cursor()
cursor.execute("DELETE FROM %s "
"WHERE cache_key = %%s" % table, [key])
transaction.commit_unless_managed(using=db)
return default
value = connections[db].ops.process_clob(row[1])
return pickle.loads(base64.b64decode(force_bytes(value)))
def create(self, **kwargs):
kwargs[self.content_type_field_name] = self.content_type
kwargs[self.object_id_field_name] = self.pk_val
db = router.db_for_write(self.model, instance=self.instance)
return super(GenericRelatedObjectManager, self).using(db).create(**kwargs)
def clear(self):
db = router.db_for_write(self.model, instance=self.instance)
for obj in self.all():
obj.delete(using=db)
def remove(self, *objs):
db = router.db_for_write(self.model, instance=self.instance)
for obj in objs:
obj.delete(using=db)
def clear(self):
db = router.db_for_write(self.cache_model_class)
table = connections[db].ops.quote_name(self._table)
cursor = connections[db].cursor()
cursor.execute('DELETE FROM %s' % table)
def delete_selected(modeladmin, request, queryset):
"""
Default action which deletes the selected objects.
This action first displays a confirmation page whichs shows all the
deleteable objects, or, if the user has no permission one of the related
childs (foreignkeys), a "permission denied" message.
Next, it delets all selected objects and redirects back to the change list.
"""
opts = modeladmin.model._meta
app_label = opts.app_label
# Check that the user has delete permission for the actual model
if not modeladmin.has_delete_permission(request):
raise PermissionDenied
using = router.db_for_write(modeladmin.model)
# Populate deletable_objects, a data structure of all related objects that
# will also be deleted.
deletable_objects, perms_needed, protected = get_deleted_objects(
queryset, opts, request.user, modeladmin.admin_site, using)
# The user has already confirmed the deletion.
# Do the deletion and return a None to display the change list view again.
if request.POST.get('post'):
if perms_needed:
raise PermissionDenied
n = queryset.count()
if n:
for obj in queryset:
obj_display = force_text(obj)
modeladmin.log_deletion(request, obj, obj_display)
queryset.delete()
modeladmin.message_user(request, _("Successfully deleted %(count)d %(items)s.") % {
"count": n, "items": model_ngettext(modeladmin.opts, n)
})
# Return None to display the change list page again.
return None
if len(queryset) == 1:
objects_name = force_text(opts.verbose_name)
else:
objects_name = force_text(opts.verbose_name_plural)
if perms_needed or protected:
title = _("Cannot delete %(name)s") % {"name": objects_name}
else:
title = _("Are you sure?")
context = {
"title": title,
"objects_name": objects_name,
"deletable_objects": [deletable_objects],
'queryset': queryset,
"perms_lacking": perms_needed,
"protected": protected,
"opts": opts,
"app_label": app_label,
'action_checkbox_name': helpers.ACTION_CHECKBOX_NAME,
}
# Display the confirmation page
return TemplateResponse(request, modeladmin.delete_selected_confirmation_template or [
"admin/%s/%s/delete_selected_confirmation.html" % (app_label, opts.object_name.lower()),
"admin/%s/delete_selected_confirmation.html" % app_label,
"admin/delete_selected_confirmation.html"
], context, current_app=modeladmin.admin_site.name)
def save_base(
self, raw=False, cls=None, origin=None, force_insert=False, force_update=False, using=None, update_fields=None
):
"""
Does the heavy-lifting involved in saving. Subclasses shouldn't need to
override this method. It's separate from save() in order to hide the
need for overrides of save() to pass around internal-only parameters
('raw', 'cls', and 'origin').
"""
using = using or router.db_for_write(self.__class__, instance=self)
assert not (force_insert and (force_update or update_fields))
assert update_fields is None or len(update_fields) > 0
if cls is None:
cls = self.__class__
meta = cls._meta
if not meta.proxy:
origin = cls
else:
meta = cls._meta
if origin and not meta.auto_created:
signals.pre_save.send(sender=origin, instance=self, raw=raw, using=using, update_fields=update_fields)
# If we are in a raw save, save the object exactly as presented.
# That means that we don't try to be smart about saving attributes
# that might have come from the parent class - we just save the
# attributes we have been given to the class we have been given.
# We also go through this process to defer the save of proxy objects
# to their actual underlying model.
if not raw or meta.proxy:
if meta.proxy:
org = cls
else:
org = None
for parent, field in meta.parents.items():
# At this point, parent's primary key field may be unknown
# (for example, from administration form which doesn't fill
# this field). If so, fill it.
if (
field
and getattr(self, parent._meta.pk.attname) is None
and getattr(self, field.attname) is not None
):
setattr(self, parent._meta.pk.attname, getattr(self, field.attname))
self.save_base(cls=parent, origin=org, using=using, update_fields=update_fields)
if field:
setattr(self, field.attname, self._get_pk_val(parent._meta))
if meta.proxy:
return
if not meta.proxy:
non_pks = [f for f in meta.local_fields if not f.primary_key]
if update_fields:
non_pks = [f for f in non_pks if f.name in update_fields or f.attname in update_fields]
# First, try an UPDATE. If that doesn't update anything, do an INSERT.
pk_val = self._get_pk_val(meta)
pk_set = pk_val is not None
record_exists = True
manager = cls._base_manager
if pk_set:
# Determine if we should do an update (pk already exists, forced update,
# no force_insert)
if (force_update or update_fields) or (
not force_insert and manager.using(using).filter(pk=pk_val).exists()
):
if force_update or non_pks:
values = [
(f, None, (raw and getattr(self, f.attname) or f.pre_save(self, False))) for f in non_pks
]
if values:
rows = manager.using(using).filter(pk=pk_val)._update(values)
if force_update and not rows:
raise DatabaseError("Forced update did not affect any rows.")
if update_fields and not rows:
raise DatabaseError("Save with update_fields did not affect any rows.")
else:
record_exists = False
if not pk_set or not record_exists:
if meta.order_with_respect_to:
# If this is a model with an order_with_respect_to
# autopopulate the _order field
field = meta.order_with_respect_to
order_value = manager.using(using).filter(**{field.name: getattr(self, field.attname)}).count()
self._order = order_value
fields = meta.local_fields
if not pk_set:
if force_update or update_fields:
raise ValueError("Cannot force an update in save() with no primary key.")
fields = [f for f in fields if not isinstance(f, AutoField)]
record_exists = False
update_pk = bool(meta.has_auto_field and not pk_set)
result = manager._insert([self], fields=fields, return_id=update_pk, using=using, raw=raw)
if update_pk:
setattr(self, meta.pk.attname, result)
transaction.commit_unless_managed(using=using)
# Store the database on which the object was saved
self._state.db = using
# Once saved, this is no longer a to-be-added instance.
self._state.adding = False
# Signal that the save is complete
if origin and not meta.auto_created:
signals.post_save.send(
sender=origin,
instance=self,
created=(not record_exists),
update_fields=update_fields,
raw=raw,
using=using,
)
