Python sqlalchemy.orm.mapper() Examples

def before_insert(self, mapper, connection, instance):
        """Receive an object instance before that instance is inserted
        into its table.

        This is a good place to set up primary key values and such
        that aren't handled otherwise.

        Column-based attributes can be modified within this method
        which will result in the new value being inserted.  However
        *no* changes to the overall flush plan can be made, and
        manipulation of the ``Session`` will not have the desired effect.
        To manipulate the ``Session`` within an extension, use
        ``SessionExtension``.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """

        return EXT_CONTINUE 

def _accept_with(cls, orm, target):
        if isinstance(target, instrumentation.ClassManager):
            return target
        elif isinstance(target, mapperlib.Mapper):
            return target.class_manager
        elif target is orm.mapper:
            return instrumentation.ClassManager
        elif isinstance(target, type):
            if issubclass(target, mapperlib.Mapper):
                return instrumentation.ClassManager
            else:
                manager = instrumentation.manager_of_class(target)
                if manager:
                    return manager
                else:
                    return _InstanceEventsHold(target)
        return None 

def instrument_class(self, mapper, class_):
        """Receive a class when the mapper is first constructed,
        before instrumentation is applied to the mapped class.

        This event is the earliest phase of mapper construction.
        Most attributes of the mapper are not yet initialized.

        This listener can either be applied to the :class:`.Mapper`
        class overall, or to any un-mapped class which serves as a base
        for classes that will be mapped (using the ``propagate=True`` flag)::

            Base = declarative_base()

            @event.listens_for(Base, "instrument_class", propagate=True)
            def on_new_class(mapper, cls_):
                " ... "

        :param mapper: the :class:`.Mapper` which is the target
         of this event.
        :param class\_: the mapped class.

        """ 

def instrument_class(self, mapper, class_):
        """Receive a class when the mapper is first constructed,
        before instrumentation is applied to the mapped class.

        This event is the earliest phase of mapper construction.
        Most attributes of the mapper are not yet initialized.

        This listener can either be applied to the :class:`.Mapper`
        class overall, or to any un-mapped class which serves as a base
        for classes that will be mapped (using the ``propagate=True`` flag)::

            Base = declarative_base()

            @event.listens_for(Base, "instrument_class", propagate=True)
            def on_new_class(mapper, cls_):
                " ... "

        :param mapper: the :class:`.Mapper` which is the target
         of this event.
        :param class\_: the mapped class.

        """ 

def before_insert(self, mapper, connection, instance):
        """Receive an object instance before that instance is inserted
        into its table.

        This is a good place to set up primary key values and such
        that aren't handled otherwise.

        Column-based attributes can be modified within this method
        which will result in the new value being inserted.  However
        *no* changes to the overall flush plan can be made, and
        manipulation of the ``Session`` will not have the desired effect.
        To manipulate the ``Session`` within an extension, use
        ``SessionExtension``.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """

        return EXT_CONTINUE 

def reconstruct_instance(self, mapper, instance):
        """Receive an object instance after it has been created via
        ``__new__``, and after initial attribute population has
        occurred.

        This typically occurs when the instance is created based on
        incoming result rows, and is only called once for that
        instance's lifetime.

        Note that during a result-row load, this method is called upon
        the first row received for this instance.  Note that some
        attributes and collections may or may not be loaded or even
        initialized, depending on what's present in the result rows.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """
        return EXT_CONTINUE 

def reconstruct_instance(self, mapper, instance):
        """Receive an object instance after it has been created via
        ``__new__``, and after initial attribute population has
        occurred.

        This typically occurs when the instance is created based on
        incoming result rows, and is only called once for that
        instance's lifetime.

        Note that during a result-row load, this method is called upon
        the first row received for this instance.  Note that some
        attributes and collections may or may not be loaded or even
        initialized, depending on what's present in the result rows.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """
        return EXT_CONTINUE 

def instrument_class(self, mapper, class_):
        r"""Receive a class when the mapper is first constructed,
        before instrumentation is applied to the mapped class.

        This event is the earliest phase of mapper construction.
        Most attributes of the mapper are not yet initialized.

        This listener can either be applied to the :class:`.Mapper`
        class overall, or to any un-mapped class which serves as a base
        for classes that will be mapped (using the ``propagate=True`` flag)::

            Base = declarative_base()

            @event.listens_for(Base, "instrument_class", propagate=True)
            def on_new_class(mapper, cls_):
                " ... "

        :param mapper: the :class:`.Mapper` which is the target
         of this event.
        :param class\_: the mapped class.

        """ 

def _accept_with(cls, orm, target):
        if isinstance(target, instrumentation.ClassManager):
            return target
        elif isinstance(target, mapperlib.Mapper):
            return target.class_manager
        elif target is orm.mapper:
            return instrumentation.ClassManager
        elif isinstance(target, type):
            if issubclass(target, mapperlib.Mapper):
                return instrumentation.ClassManager
            else:
                manager = instrumentation.manager_of_class(target)
                if manager:
                    return manager
                else:
                    return _InstanceEventsHold(target)
        return None 

def _accept_with(cls, orm, target):
        if isinstance(target, instrumentation.ClassManager):
            return target
        elif isinstance(target, mapperlib.Mapper):
            return target.class_manager
        elif target is orm.mapper:
            return instrumentation.ClassManager
        elif isinstance(target, type):
            if issubclass(target, mapperlib.Mapper):
                return instrumentation.ClassManager
            else:
                manager = instrumentation.manager_of_class(target)
                if manager:
                    return manager
                else:
                    return _InstanceEventsHold(target)
        return None 

def reconstruct_instance(self, mapper, instance):
        """Receive an object instance after it has been created via
        ``__new__``, and after initial attribute population has
        occurred.

        This typically occurs when the instance is created based on
        incoming result rows, and is only called once for that
        instance's lifetime.

        Note that during a result-row load, this method is called upon
        the first row received for this instance.  Note that some
        attributes and collections may or may not be loaded or even
        initialized, depending on what's present in the result rows.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """
        return EXT_CONTINUE 

def before_insert(self, mapper, connection, instance):
        """Receive an object instance before that instance is inserted
        into its table.

        This is a good place to set up primary key values and such
        that aren't handled otherwise.

        Column-based attributes can be modified within this method
        which will result in the new value being inserted.  However
        *no* changes to the overall flush plan can be made, and
        manipulation of the ``Session`` will not have the desired effect.
        To manipulate the ``Session`` within an extension, use
        ``SessionExtension``.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """

        return EXT_CONTINUE 

def test_sql_bulk_insert_from_records__sqlite(self):
        engine, metadata = create_db_memory()
        fields = [
            Column("id", Integer(), primary_key=True, autoincrement=True),
            Column("sf_id", Unicode(24)),
        ]
        id_t = Table("TestTable", metadata, *fields)
        id_t.create()
        model = type("TestModel", (object,), {})
        mapper(model, id_t)

        util = bulkdata.utils.SqlAlchemyMixin()
        util.metadata = metadata
        session = create_session(bind=engine, autocommit=False)
        util.session = session
        connection = session.connection()

        util._sql_bulk_insert_from_records(
            connection=connection,
            table="TestTable",
            columns=("id", "sf_id"),
            record_iterable=([f"{x}", f"00100000000000{x}"] for x in range(10)),
        )

        assert session.query(model).count() == 10 

def reconstruct_instance(self, mapper, instance):
        """Receive an object instance after it has been created via
        ``__new__``, and after initial attribute population has
        occurred.

        This typically occurs when the instance is created based on
        incoming result rows, and is only called once for that
        instance's lifetime.

        Note that during a result-row load, this method is called upon
        the first row received for this instance.  Note that some
        attributes and collections may or may not be loaded or even
        initialized, depending on what's present in the result rows.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """
        return EXT_CONTINUE 

def before_insert(self, mapper, connection, instance):
        """Receive an object instance before that instance is inserted
        into its table.

        This is a good place to set up primary key values and such
        that aren't handled otherwise.

        Column-based attributes can be modified within this method
        which will result in the new value being inserted.  However
        *no* changes to the overall flush plan can be made, and
        manipulation of the ``Session`` will not have the desired effect.
        To manipulate the ``Session`` within an extension, use
        ``SessionExtension``.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """

        return EXT_CONTINUE 

def loaded_as_persistent(self, session, instance):
        """Intercept the "loaded as persistent" transition for a specific object.

        This event is invoked within the ORM loading process, and is invoked
        very similarly to the :meth:`.InstanceEvents.load` event.  However,
        the event here is linkable to a :class:`.Session` class or instance,
        rather than to a mapper or class hierarchy, and integrates
        with the other session lifecycle events smoothly.  The object
        is guaranteed to be present in the session's identity map when
        this event is called.


        :param session: target :class:`.Session`

        :param instance: the ORM-mapped instance being operated upon.

        .. versionadded:: 1.1

        .. seealso::

            :ref:`session_lifecycle_events`

        """ 

def _accept_with(cls, orm, target):
        if isinstance(target, instrumentation.ClassManager):
            return target
        elif isinstance(target, mapperlib.Mapper):
            return target.class_manager
        elif target is orm.mapper:
            return instrumentation.ClassManager
        elif isinstance(target, type):
            if issubclass(target, mapperlib.Mapper):
                return instrumentation.ClassManager
            else:
                manager = instrumentation.manager_of_class(target)
                if manager:
                    return manager
                else:
                    return _InstanceEventsHold(target)
        return None 

def before_update(self, mapper, connection, instance):
        """Receive an object instance before that instance is updated.

        Note that this method is called for all instances that are marked as
        "dirty", even those which have no net changes to their column-based
        attributes. An object is marked as dirty when any of its column-based
        attributes have a "set attribute" operation called or when any of its
        collections are modified. If, at update time, no column-based
        attributes have any net changes, no UPDATE statement will be issued.
        This means that an instance being sent to before_update is *not* a
        guarantee that an UPDATE statement will be issued (although you can
        affect the outcome here).

        To detect if the column-based attributes on the object have net
        changes, and will therefore generate an UPDATE statement, use
        ``object_session(instance).is_modified(instance,
        include_collections=False)``.

        Column-based attributes can be modified within this method
        which will result in the new value being updated.  However
        *no* changes to the overall flush plan can be made, and
        manipulation of the ``Session`` will not have the desired effect.
        To manipulate the ``Session`` within an extension, use
        ``SessionExtension``.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """

        return EXT_CONTINUE 

def before_delete(self, mapper, connection, instance):
        """Receive an object instance before that instance is deleted.

        Note that *no* changes to the overall flush plan can be made
        here; and manipulation of the ``Session`` will not have the
        desired effect. To manipulate the ``Session`` within an
        extension, use ``SessionExtension``.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """

        return EXT_CONTINUE 

def after_update(self, mapper, connection, instance):
        """Receive an object instance after that instance is updated.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """

        return EXT_CONTINUE 

def after_delete(self, mapper, connection, instance):
        """Receive an object instance after that instance is deleted.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """

        return EXT_CONTINUE 

def before_delete(self, mapper, connection, target):
        """Receive an object instance before a DELETE statement
        is emitted corresponding to that instance.

        This event is used to emit additional SQL statements on
        the given connection as well as to perform application
        specific bookkeeping related to a deletion event.

        The event is often called for a batch of objects of the
        same class before their DELETE statements are emitted at
        once in a later step.

        .. warning::

            Mapper-level flush events only allow **very limited operations**,
            on attributes local to the row being operated upon only,
            as well as allowing any SQL to be emitted on the given
            :class:`.Connection`.  **Please read fully** the notes
            at :ref:`session_persistence_mapper` for guidelines on using
            these methods; generally, the :meth:`.SessionEvents.before_flush`
            method should be preferred for general on-flush changes.

        :param mapper: the :class:`.Mapper` which is the target
         of this event.
        :param connection: the :class:`.Connection` being used to
         emit DELETE statements for this instance.  This
         provides a handle into the current transaction on the
         target database specific to this instance.
        :param target: the mapped instance being deleted.  If
         the event is configured with ``raw=True``, this will
         instead be the :class:`.InstanceState` state-management
         object associated with the instance.
        :return: No return value is supported by this event.

        .. seealso::

            :ref:`session_persistence_events`

        """ 

def test_create_record_type_table(self, mapper, table):
        util = bulkdata.utils.SqlAlchemyMixin()
        util.models = {}
        util.metadata = mock.Mock()

        util._create_record_type_table("Account_rt_mapping")

        self.assertIn("Account_rt_mapping", util.models) 

def after_delete(self, mapper, connection, target):
        """Receive an object instance after a DELETE statement
        has been emitted corresponding to that instance.

        This event is used to emit additional SQL statements on
        the given connection as well as to perform application
        specific bookkeeping related to a deletion event.

        The event is often called for a batch of objects of the
        same class after their DELETE statements have been emitted at
        once in a previous step.

        .. warning::

            Mapper-level flush events only allow **very limited operations**,
            on attributes local to the row being operated upon only,
            as well as allowing any SQL to be emitted on the given
            :class:`.Connection`.  **Please read fully** the notes
            at :ref:`session_persistence_mapper` for guidelines on using
            these methods; generally, the :meth:`.SessionEvents.before_flush`
            method should be preferred for general on-flush changes.

        :param mapper: the :class:`.Mapper` which is the target
         of this event.
        :param connection: the :class:`.Connection` being used to
         emit DELETE statements for this instance.  This
         provides a handle into the current transaction on the
         target database specific to this instance.
        :param target: the mapped instance being deleted.  If
         the event is configured with ``raw=True``, this will
         instead be the :class:`.InstanceState` state-management
         object associated with the instance.
        :return: No return value is supported by this event.

        .. seealso::

            :ref:`session_persistence_events`

        """ 

def before_delete(self, mapper, connection, target):
        """Receive an object instance before a DELETE statement
        is emitted corresponding to that instance.

        This event is used to emit additional SQL statements on
        the given connection as well as to perform application
        specific bookkeeping related to a deletion event.

        The event is often called for a batch of objects of the
        same class before their DELETE statements are emitted at
        once in a later step.

        .. warning::

            Mapper-level flush events only allow **very limited operations**,
            on attributes local to the row being operated upon only,
            as well as allowing any SQL to be emitted on the given
            :class:`.Connection`.  **Please read fully** the notes
            at :ref:`session_persistence_mapper` for guidelines on using
            these methods; generally, the :meth:`.SessionEvents.before_flush`
            method should be preferred for general on-flush changes.

        :param mapper: the :class:`.Mapper` which is the target
         of this event.
        :param connection: the :class:`.Connection` being used to
         emit DELETE statements for this instance.  This
         provides a handle into the current transaction on the
         target database specific to this instance.
        :param target: the mapped instance being deleted.  If
         the event is configured with ``raw=True``, this will
         instead be the :class:`.InstanceState` state-management
         object associated with the instance.
        :return: No return value is supported by this event.

        .. seealso::

            :ref:`session_persistence_events`

        """ 

def after_delete(self, mapper, connection, target):
        """Receive an object instance after a DELETE statement
        has been emitted corresponding to that instance.

        This event is used to emit additional SQL statements on
        the given connection as well as to perform application
        specific bookkeeping related to a deletion event.

        The event is often called for a batch of objects of the
        same class after their DELETE statements have been emitted at
        once in a previous step.

        .. warning::

            Mapper-level flush events only allow **very limited operations**,
            on attributes local to the row being operated upon only,
            as well as allowing any SQL to be emitted on the given
            :class:`.Connection`.  **Please read fully** the notes
            at :ref:`session_persistence_mapper` for guidelines on using
            these methods; generally, the :meth:`.SessionEvents.before_flush`
            method should be preferred for general on-flush changes.

        :param mapper: the :class:`.Mapper` which is the target
         of this event.
        :param connection: the :class:`.Connection` being used to
         emit DELETE statements for this instance.  This
         provides a handle into the current transaction on the
         target database specific to this instance.
        :param target: the mapped instance being deleted.  If
         the event is configured with ``raw=True``, this will
         instead be the :class:`.InstanceState` state-management
         object associated with the instance.
        :return: No return value is supported by this event.

        .. seealso::

            :ref:`session_persistence_events`

        """ 

def before_update(self, mapper, connection, instance):
        """Receive an object instance before that instance is updated.

        Note that this method is called for all instances that are marked as
        "dirty", even those which have no net changes to their column-based
        attributes. An object is marked as dirty when any of its column-based
        attributes have a "set attribute" operation called or when any of its
        collections are modified. If, at update time, no column-based
        attributes have any net changes, no UPDATE statement will be issued.
        This means that an instance being sent to before_update is *not* a
        guarantee that an UPDATE statement will be issued (although you can
        affect the outcome here).

        To detect if the column-based attributes on the object have net
        changes, and will therefore generate an UPDATE statement, use
        ``object_session(instance).is_modified(instance,
        include_collections=False)``.

        Column-based attributes can be modified within this method
        which will result in the new value being updated.  However
        *no* changes to the overall flush plan can be made, and
        manipulation of the ``Session`` will not have the desired effect.
        To manipulate the ``Session`` within an extension, use
        ``SessionExtension``.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """

        return EXT_CONTINUE 

def after_update(self, mapper, connection, instance):
        """Receive an object instance after that instance is updated.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """

        return EXT_CONTINUE 

def after_delete(self, mapper, connection, instance):
        """Receive an object instance after that instance is deleted.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """

        return EXT_CONTINUE 

def init_instance(self, mapper, class_, oldinit, instance, args, kwargs):
        """Receive an instance when its constructor is called.

        This method is only called during a userland construction of
        an object.  It is not called when an object is loaded from the
        database.

        The return value is only significant within the ``MapperExtension``
        chain; the parent mapper's behavior isn't modified by this method.

        """
        return EXT_CONTINUE