Method update

cassandra/cqlengine/query.py:1203–1334

Performs an update on the row selected by the queryset. Include values to update in the update like so: .. code-block:: python Model.objects(key=n).update(value='x') Passing in updates for columns which are not part of the model will raise a Validation

(self, **values)

        return clone

    def update(self, **values):
        """
        Performs an update on the row selected by the queryset. Include values to update in the
        update like so:

        .. code-block:: python

            Model.objects(key=n).update(value='x')

        Passing in updates for columns which are not part of the model will raise a ValidationError.

        Per column validation will be performed, but instance level validation will not
        (i.e., `Model.validate` is not called).  This is sometimes referred to as a blind update.

        For example:

        .. code-block:: python

            class User(Model):
                id = Integer(primary_key=True)
                name = Text()

            setup(["localhost"], "test")
            sync_table(User)

            u = User.create(id=1, name="jon")

            User.objects(id=1).update(name="Steve")

            # sets name to null
            User.objects(id=1).update(name=None)


        Also supported is blindly adding and removing elements from container columns,
        without loading a model instance from Cassandra.

        Using the syntax `.update(column_name={x, y, z})` will overwrite the contents of the container, like updating a
        non container column. However, adding `__<operation>` to the end of the keyword arg, makes the update call add
        or remove items from the collection, without overwriting then entire column.

        Given the model below, here are the operations that can be performed on the different container columns:

        .. code-block:: python

            class Row(Model):
                row_id      = columns.Integer(primary_key=True)
                set_column  = columns.Set(Integer)
                list_column = columns.List(Integer)
                map_column  = columns.Map(Integer, Integer)

        :class:`~cqlengine.columns.Set`

        - `add`: adds the elements of the given set to the column
        - `remove`: removes the elements of the given set to the column


        .. code-block:: python