Classe « Query »

Méthode sqlalchemy.orm.Query.one_or_none

Signature de la méthode one_or_none

def one_or_none(self) 

Description

one_or_none.__doc__

Return at most one result or raise an exception.

        Returns ``None`` if the query selects
        no rows.  Raises ``sqlalchemy.orm.exc.MultipleResultsFound``
        if multiple object identities are returned, or if multiple
        rows are returned for a query that returns only scalar values
        as opposed to full identity-mapped entities.

        Calling :meth:`_query.Query.one_or_none`
        results in an execution of the
        underlying query.

        .. versionadded:: 1.0.9

            Added :meth:`_query.Query.one_or_none`

        .. seealso::

            :meth:`_query.Query.first`

            :meth:`_query.Query.one`