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, )