Classe « Session »

Méthode sqlalchemy.orm.Session.begin_nested

Signature de la méthode begin_nested

def begin_nested(self) 

Description

begin_nested.__doc__

Begin a "nested" transaction on this Session, e.g. SAVEPOINT.

        The target database(s) and associated drivers must support SQL
        SAVEPOINT for this method to function correctly.

        For documentation on SAVEPOINT
        transactions, please see :ref:`session_begin_nested`.

        :return: the :class:`.SessionTransaction` object.  Note that
         :class:`.SessionTransaction` acts as a context manager, allowing
         :meth:`.Session.begin_nested` to be used in a "with" block.
         See :ref:`session_begin_nested` for a usage example.

        .. seealso::

            :ref:`session_begin_nested`

            :ref:`pysqlite_serializable` - special workarounds required
            with the SQLite driver in order for SAVEPOINT to work
            correctly.