diff options
| -rw-r--r-- | MANIFEST.in | 1 | ||||
| -rw-r--r-- | lib/sqlalchemy/engine/base.py | 8 | ||||
| -rw-r--r-- | lib/sqlalchemy/ext/asyncio/engine.py | 275 | ||||
| -rw-r--r-- | lib/sqlalchemy/ext/asyncio/scoping.py | 1121 | ||||
| -rw-r--r-- | lib/sqlalchemy/ext/asyncio/session.py | 510 | ||||
| -rw-r--r-- | lib/sqlalchemy/orm/scoping.py | 1577 | ||||
| -rw-r--r-- | lib/sqlalchemy/orm/session.py | 6 | ||||
| -rw-r--r-- | lib/sqlalchemy/testing/plugin/plugin_base.py | 17 | ||||
| -rw-r--r-- | lib/sqlalchemy/testing/plugin/pytestplugin.py | 18 | ||||
| -rw-r--r-- | lib/sqlalchemy/util/compat.py | 8 | ||||
| -rw-r--r-- | lib/sqlalchemy/util/langhelpers.py | 106 | ||||
| -rw-r--r-- | test/ext/asyncio/test_scoping_py3k.py | 3 | ||||
| -rw-r--r-- | tools/generate_proxy_methods.py | 413 |
13 files changed, 3936 insertions, 127 deletions
diff --git a/MANIFEST.in b/MANIFEST.in index eb447a0bd..7a272fe6b 100644 --- a/MANIFEST.in +++ b/MANIFEST.in @@ -4,6 +4,7 @@ recursive-include doc *.html *.css *.txt *.js *.png *.py Makefile *.rst *.sty recursive-include examples *.py *.xml recursive-include test *.py *.dat *.testpatch +recursive-include tools *.py # for some reason in some environments stale Cython .c files # are being pulled in, these should never be in a dist diff --git a/lib/sqlalchemy/engine/base.py b/lib/sqlalchemy/engine/base.py index f3d30860a..5c446a91d 100644 --- a/lib/sqlalchemy/engine/base.py +++ b/lib/sqlalchemy/engine/base.py @@ -2672,14 +2672,18 @@ class Engine( @property def name(self) -> str: """String name of the :class:`~sqlalchemy.engine.interfaces.Dialect` - in use by this :class:`Engine`.""" + in use by this :class:`Engine`. + + """ return self.dialect.name @property def driver(self) -> str: """Driver name of the :class:`~sqlalchemy.engine.interfaces.Dialect` - in use by this :class:`Engine`.""" + in use by this :class:`Engine`. + + """ return self.dialect.driver diff --git a/lib/sqlalchemy/ext/asyncio/engine.py b/lib/sqlalchemy/ext/asyncio/engine.py index fcf3b974d..3b54405c1 100644 --- a/lib/sqlalchemy/ext/asyncio/engine.py +++ b/lib/sqlalchemy/ext/asyncio/engine.py @@ -4,6 +4,10 @@ # # This module is part of SQLAlchemy and is released under # the MIT License: https://www.opensource.org/licenses/mit-license.php +from __future__ import annotations + +from typing import Any + from . import exc as async_exc from .base import ProxyComparable from .base import StartableContext @@ -72,7 +76,7 @@ class AsyncConnectable: @util.create_proxy_methods( Connection, - ":class:`_future.Connection`", + ":class:`_engine.Connection`", ":class:`_asyncio.AsyncConnection`", classmethods=[], methods=[], @@ -125,6 +129,7 @@ class AsyncConnection(ProxyComparable, StartableContext, AsyncConnectable): .. seealso:: :ref:`asyncio_events` + """ sync_engine: Engine @@ -137,6 +142,7 @@ class AsyncConnection(ProxyComparable, StartableContext, AsyncConnectable): .. seealso:: :ref:`asyncio_events` + """ @classmethod @@ -552,10 +558,100 @@ class AsyncConnection(ProxyComparable, StartableContext, AsyncConnectable): async def __aexit__(self, type_, value, traceback): await self.close() + # START PROXY METHODS AsyncConnection + + # code within this block is **programmatically, + # statically generated** by tools/generate_proxy_methods.py + + @property + def closed(self) -> Any: + r"""Return True if this connection is closed. + + .. container:: class_bases + + Proxied for the :class:`_engine.Connection` class + on behalf of the :class:`_asyncio.AsyncConnection` class. + + """ # noqa: E501 + + return self._proxied.closed + + @property + def invalidated(self) -> Any: + r"""Return True if this connection was invalidated. + + .. container:: class_bases + + Proxied for the :class:`_engine.Connection` class + on behalf of the :class:`_asyncio.AsyncConnection` class. + + This does not indicate whether or not the connection was + invalidated at the pool level, however + + + """ # noqa: E501 + + return self._proxied.invalidated + + @property + def dialect(self) -> Any: + r"""Proxy for the :attr:`_engine.Connection.dialect` attribute + on behalf of the :class:`_asyncio.AsyncConnection` class. + + """ # noqa: E501 + + return self._proxied.dialect + + @dialect.setter + def dialect(self, attr: Any) -> None: + self._proxied.dialect = attr + + @property + def default_isolation_level(self) -> Any: + r"""The default isolation level assigned to this + :class:`_engine.Connection`. + + .. container:: class_bases + + Proxied for the :class:`_engine.Connection` class + on behalf of the :class:`_asyncio.AsyncConnection` class. + + This is the isolation level setting that the + :class:`_engine.Connection` + has when first procured via the :meth:`_engine.Engine.connect` method. + This level stays in place until the + :paramref:`.Connection.execution_options.isolation_level` is used + to change the setting on a per-:class:`_engine.Connection` basis. + + Unlike :meth:`_engine.Connection.get_isolation_level`, + this attribute is set + ahead of time from the first connection procured by the dialect, + so SQL query is not invoked when this accessor is called. + + .. versionadded:: 0.9.9 + + .. seealso:: + + :meth:`_engine.Connection.get_isolation_level` + - view current level + + :paramref:`_sa.create_engine.isolation_level` + - set per :class:`_engine.Engine` isolation level + + :paramref:`.Connection.execution_options.isolation_level` + - set per :class:`_engine.Connection` isolation level + + + """ # noqa: E501 + + return self._proxied.default_isolation_level + + # END PROXY METHODS AsyncConnection + @util.create_proxy_methods( Engine, - ":class:`_future.Engine`", + ":class:`_engine.Engine`", ":class:`_asyncio.AsyncEngine`", classmethods=[], methods=[ @@ -701,6 +797,181 @@ class AsyncEngine(ProxyComparable, AsyncConnectable): return await greenlet_spawn(self.sync_engine.dispose) + # START PROXY METHODS AsyncEngine + + # code within this block is **programmatically, + # statically generated** by tools/generate_proxy_methods.py + + def clear_compiled_cache(self) -> None: + r"""Clear the compiled cache associated with the dialect. + + .. container:: class_bases + + Proxied for the :class:`_engine.Engine` class on + behalf of the :class:`_asyncio.AsyncEngine` class. + + This applies **only** to the built-in cache that is established + via the :paramref:`_engine.create_engine.query_cache_size` parameter. + It will not impact any dictionary caches that were passed via the + :paramref:`.Connection.execution_options.query_cache` parameter. + + .. versionadded:: 1.4 + + + """ # noqa: E501 + + return self._proxied.clear_compiled_cache() + + def update_execution_options(self, **opt: Any) -> None: + r"""Update the default execution_options dictionary + of this :class:`_engine.Engine`. + + .. container:: class_bases + + Proxied for the :class:`_engine.Engine` class on + behalf of the :class:`_asyncio.AsyncEngine` class. + + The given keys/values in \**opt are added to the + default execution options that will be used for + all connections. The initial contents of this dictionary + can be sent via the ``execution_options`` parameter + to :func:`_sa.create_engine`. + + .. seealso:: + + :meth:`_engine.Connection.execution_options` + + :meth:`_engine.Engine.execution_options` + + + """ # noqa: E501 + + return self._proxied.update_execution_options(**opt) + + def get_execution_options(self) -> _ExecuteOptions: + r"""Get the non-SQL options which will take effect during execution. + + .. container:: class_bases + + Proxied for the :class:`_engine.Engine` class on + behalf of the :class:`_asyncio.AsyncEngine` class. + + .. versionadded: 1.3 + + .. seealso:: + + :meth:`_engine.Engine.execution_options` + + """ # noqa: E501 + + return self._proxied.get_execution_options() + + @property + def url(self) -> URL: + r"""Proxy for the :attr:`_engine.Engine.url` attribute + on behalf of the :class:`_asyncio.AsyncEngine` class. + + """ # noqa: E501 + + return self._proxied.url + + @url.setter + def url(self, attr: URL) -> None: + self._proxied.url = attr + + @property + def pool(self) -> Pool: + r"""Proxy for the :attr:`_engine.Engine.pool` attribute + on behalf of the :class:`_asyncio.AsyncEngine` class. + + """ # noqa: E501 + + return self._proxied.pool + + @pool.setter + def pool(self, attr: Pool) -> None: + self._proxied.pool = attr + + @property + def dialect(self) -> Dialect: + r"""Proxy for the :attr:`_engine.Engine.dialect` attribute + on behalf of the :class:`_asyncio.AsyncEngine` class. + + """ # noqa: E501 + + return self._proxied.dialect + + @dialect.setter + def dialect(self, attr: Dialect) -> None: + self._proxied.dialect = attr + + @property + def engine(self) -> Any: + r""".. container:: class_bases + + Proxied for the :class:`_engine.Engine` class + on behalf of the :class:`_asyncio.AsyncEngine` class. + + + """ # noqa: E501 + + return self._proxied.engine + + @property + def name(self) -> Any: + r"""String name of the :class:`~sqlalchemy.engine.interfaces.Dialect` + in use by this :class:`Engine`. + + .. container:: class_bases + + Proxied for the :class:`_engine.Engine` class + on behalf of the :class:`_asyncio.AsyncEngine` class. + + + """ # noqa: E501 + + return self._proxied.name + + @property + def driver(self) -> Any: + r"""Driver name of the :class:`~sqlalchemy.engine.interfaces.Dialect` + in use by this :class:`Engine`. + + .. container:: class_bases + + Proxied for the :class:`_engine.Engine` class + on behalf of the :class:`_asyncio.AsyncEngine` class. + + + """ # noqa: E501 + + return self._proxied.driver + + @property + def echo(self) -> Any: + r"""When ``True``, enable log output for this element. + + .. container:: class_bases + + Proxied for the :class:`_engine.Engine` class + on behalf of the :class:`_asyncio.AsyncEngine` class. + + This has the effect of setting the Python logging level for the namespace + of this element's class and object reference. A value of boolean ``True`` + indicates that the loglevel ``logging.INFO`` will be set for the logger, + whereas the string value ``debug`` will set the loglevel to + ``logging.DEBUG``. + + """ # noqa: E501 + + return self._proxied.echo + + @echo.setter + def echo(self, attr: Any) -> None: + self._proxied.echo = attr + + # END PROXY METHODS AsyncEngine + class AsyncTransaction(ProxyComparable, StartableContext): """An asyncio proxy for a :class:`_engine.Transaction`.""" diff --git a/lib/sqlalchemy/ext/asyncio/scoping.py b/lib/sqlalchemy/ext/asyncio/scoping.py index 8eca8c524..cc5725125 100644 --- a/lib/sqlalchemy/ext/asyncio/scoping.py +++ b/lib/sqlalchemy/ext/asyncio/scoping.py @@ -5,7 +5,12 @@ # This module is part of SQLAlchemy and is released under # the MIT License: https://www.opensource.org/licenses/mit-license.php +from __future__ import annotations + +from typing import Any + from .session import AsyncSession +from ... import util from ...orm.scoping import ScopedSessionMixin from ...util import create_proxy_methods from ...util import ScopedRegistry @@ -105,3 +110,1119 @@ class async_scoped_session(ScopedSessionMixin): if self.registry.has(): await self.registry().close() self.registry.clear() + + # START PROXY METHODS async_scoped_session + + # code within this block is **programmatically, + # statically generated** by tools/generate_proxy_methods.py + + def __contains__(self, instance): + r"""Return True if the instance is associated with this session. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + The instance may be pending or persistent within the Session for a + result of True. + + + + """ # noqa: E501 + + return self._proxied.__contains__(instance) + + def __iter__(self): + r"""Iterate over all pending or persistent instances within this + Session. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + """ + + return self._proxied.__iter__() + + def add(self, instance: Any, _warn: bool = True) -> None: + r"""Place an object in the ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + Its state will be persisted to the database on the next flush + operation. + + Repeated calls to ``add()`` will be ignored. The opposite of ``add()`` + is ``expunge()``. + + + + """ # noqa: E501 + + return self._proxied.add(instance, _warn=_warn) + + def add_all(self, instances): + r"""Add the given collection of instances to this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + + """ # noqa: E501 + + return self._proxied.add_all(instances) + + def begin(self): + r"""Return an :class:`_asyncio.AsyncSessionTransaction` object. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + The underlying :class:`_orm.Session` will perform the + "begin" action when the :class:`_asyncio.AsyncSessionTransaction` + object is entered:: + + async with async_session.begin(): + # .. ORM transaction is begun + + Note that database IO will not normally occur when the session-level + transaction is begun, as database transactions begin on an + on-demand basis. However, the begin block is async to accommodate + for a :meth:`_orm.SessionEvents.after_transaction_create` + event hook that may perform IO. + + For a general description of ORM begin, see + :meth:`_orm.Session.begin`. + + + """ # noqa: E501 + + return self._proxied.begin() + + def begin_nested(self): + r"""Return an :class:`_asyncio.AsyncSessionTransaction` object + which will begin a "nested" transaction, e.g. SAVEPOINT. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + Behavior is the same as that of :meth:`_asyncio.AsyncSession.begin`. + + For a general description of ORM begin nested, see + :meth:`_orm.Session.begin_nested`. + + + """ # noqa: E501 + + return self._proxied.begin_nested() + + async def close(self): + r"""Close out the transactional resources and ORM objects used by this + :class:`_asyncio.AsyncSession`. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + This expunges all ORM objects associated with this + :class:`_asyncio.AsyncSession`, ends any transaction in progress and + :term:`releases` any :class:`_asyncio.AsyncConnection` objects which + this :class:`_asyncio.AsyncSession` itself has checked out from + associated :class:`_asyncio.AsyncEngine` objects. The operation then + leaves the :class:`_asyncio.AsyncSession` in a state which it may be + used again. + + .. tip:: + + The :meth:`_asyncio.AsyncSession.close` method **does not prevent + the Session from being used again**. The + :class:`_asyncio.AsyncSession` itself does not actually have a + distinct "closed" state; it merely means the + :class:`_asyncio.AsyncSession` will release all database + connections and ORM objects. + + + .. seealso:: + + :ref:`session_closing` - detail on the semantics of + :meth:`_asyncio.AsyncSession.close` + + + """ # noqa: E501 + + return await self._proxied.close() + + async def commit(self): + r"""Commit the current transaction in progress. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + """ # noqa: E501 + + return await self._proxied.commit() + + async def connection(self, **kw): + r"""Return a :class:`_asyncio.AsyncConnection` object corresponding to + this :class:`.Session` object's transactional state. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + This method may also be used to establish execution options for the + database connection used by the current transaction. + + .. versionadded:: 1.4.24 Added **kw arguments which are passed through + to the underlying :meth:`_orm.Session.connection` method. + + .. seealso:: + + :meth:`_orm.Session.connection` - main documentation for + "connection" + + + """ # noqa: E501 + + return await self._proxied.connection(**kw) + + async def delete(self, instance): + r"""Mark an instance as deleted. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + The database delete operation occurs upon ``flush()``. + + As this operation may need to cascade along unloaded relationships, + it is awaitable to allow for those queries to take place. + + .. seealso:: + + :meth:`_orm.Session.delete` - main documentation for delete + + + """ # noqa: E501 + + return await self._proxied.delete(instance) + + async def execute( + self, + statement, + params=None, + execution_options=util.EMPTY_DICT, + bind_arguments=None, + **kw, + ): + r"""Execute a statement and return a buffered + :class:`_engine.Result` object. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. seealso:: + + :meth:`_orm.Session.execute` - main documentation for execute + + + """ # noqa: E501 + + return await self._proxied.execute( + statement, + params=params, + execution_options=execution_options, + bind_arguments=bind_arguments, + **kw, + ) + + def expire(self, instance, attribute_names=None): + r"""Expire the attributes on an instance. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + Marks the attributes of an instance as out of date. When an expired + attribute is next accessed, a query will be issued to the + :class:`.Session` object's current transactional context in order to + load all expired attributes for the given instance. Note that + a highly isolated transaction will return the same values as were + previously read in that same transaction, regardless of changes + in database state outside of that transaction. + + To expire all objects in the :class:`.Session` simultaneously, + use :meth:`Session.expire_all`. + + The :class:`.Session` object's default behavior is to + expire all state whenever the :meth:`Session.rollback` + or :meth:`Session.commit` methods are called, so that new + state can be loaded for the new transaction. For this reason, + calling :meth:`Session.expire` only makes sense for the specific + case that a non-ORM SQL statement was emitted in the current + transaction. + + :param instance: The instance to be refreshed. + :param attribute_names: optional list of string attribute names + indicating a subset of attributes to be expired. + + .. seealso:: + + :ref:`session_expire` - introductory material + + :meth:`.Session.expire` + + :meth:`.Session.refresh` + + :meth:`_orm.Query.populate_existing` + + + + """ # noqa: E501 + + return self._proxied.expire(instance, attribute_names=attribute_names) + + def expire_all(self): + r"""Expires all persistent instances within this Session. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + When any attributes on a persistent instance is next accessed, + a query will be issued using the + :class:`.Session` object's current transactional context in order to + load all expired attributes for the given instance. Note that + a highly isolated transaction will return the same values as were + previously read in that same transaction, regardless of changes + in database state outside of that transaction. + + To expire individual objects and individual attributes + on those objects, use :meth:`Session.expire`. + + The :class:`.Session` object's default behavior is to + expire all state whenever the :meth:`Session.rollback` + or :meth:`Session.commit` methods are called, so that new + state can be loaded for the new transaction. For this reason, + calling :meth:`Session.expire_all` is not usually needed, + assuming the transaction is isolated. + + .. seealso:: + + :ref:`session_expire` - introductory material + + :meth:`.Session.expire` + + :meth:`.Session.refresh` + + :meth:`_orm.Query.populate_existing` + + + + """ # noqa: E501 + + return self._proxied.expire_all() + + def expunge(self, instance): + r"""Remove the `instance` from this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This will free all internal references to the instance. Cascading + will be applied according to the *expunge* cascade rule. + + + + """ # noqa: E501 + + return self._proxied.expunge(instance) + + def expunge_all(self): + r"""Remove all object instances from this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This is equivalent to calling ``expunge(obj)`` on all objects in this + ``Session``. + + + + """ # noqa: E501 + + return self._proxied.expunge_all() + + async def flush(self, objects=None): + r"""Flush all the object changes to the database. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. seealso:: + + :meth:`_orm.Session.flush` - main documentation for flush + + + """ # noqa: E501 + + return await self._proxied.flush(objects=objects) + + async def get( + self, + entity, + ident, + options=None, + populate_existing=False, + with_for_update=None, + identity_token=None, + ): + r"""Return an instance based on the given primary key identifier, + or ``None`` if not found. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. seealso:: + + :meth:`_orm.Session.get` - main documentation for get + + + + """ # noqa: E501 + + return await self._proxied.get( + entity, + ident, + options=options, + populate_existing=populate_existing, + with_for_update=with_for_update, + identity_token=identity_token, + ) + + def get_bind(self, mapper=None, clause=None, bind=None, **kw): + r"""Return a "bind" to which the synchronous proxied :class:`_orm.Session` + is bound. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + Unlike the :meth:`_orm.Session.get_bind` method, this method is + currently **not** used by this :class:`.AsyncSession` in any way + in order to resolve engines for requests. + + .. note:: + + This method proxies directly to the :meth:`_orm.Session.get_bind` + method, however is currently **not** useful as an override target, + in contrast to that of the :meth:`_orm.Session.get_bind` method. + The example below illustrates how to implement custom + :meth:`_orm.Session.get_bind` schemes that work with + :class:`.AsyncSession` and :class:`.AsyncEngine`. + + The pattern introduced at :ref:`session_custom_partitioning` + illustrates how to apply a custom bind-lookup scheme to a + :class:`_orm.Session` given a set of :class:`_engine.Engine` objects. + To apply a corresponding :meth:`_orm.Session.get_bind` implementation + for use with a :class:`.AsyncSession` and :class:`.AsyncEngine` + objects, continue to subclass :class:`_orm.Session` and apply it to + :class:`.AsyncSession` using + :paramref:`.AsyncSession.sync_session_class`. The inner method must + continue to return :class:`_engine.Engine` instances, which can be + acquired from a :class:`_asyncio.AsyncEngine` using the + :attr:`_asyncio.AsyncEngine.sync_engine` attribute:: + + # using example from "Custom Vertical Partitioning" + + + import random + + from sqlalchemy.ext.asyncio import AsyncSession + from sqlalchemy.ext.asyncio import create_async_engine + from sqlalchemy.orm import Session, sessionmaker + + # construct async engines w/ async drivers + engines = { + 'leader':create_async_engine("sqlite+aiosqlite:///leader.db"), + 'other':create_async_engine("sqlite+aiosqlite:///other.db"), + 'follower1':create_async_engine("sqlite+aiosqlite:///follower1.db"), + 'follower2':create_async_engine("sqlite+aiosqlite:///follower2.db"), + } + + class RoutingSession(Session): + def get_bind(self, mapper=None, clause=None, **kw): + # within get_bind(), return sync engines + if mapper and issubclass(mapper.class_, MyOtherClass): + return engines['other'].sync_engine + elif self._flushing or isinstance(clause, (Update, Delete)): + return engines['leader'].sync_engine + else: + return engines[ + random.choice(['follower1','follower2']) + ].sync_engine + + # apply to AsyncSession using sync_session_class + AsyncSessionMaker = sessionmaker( + class_=AsyncSession, + sync_session_class=RoutingSession + ) + + The :meth:`_orm.Session.get_bind` method is called in a non-asyncio, + implicitly non-blocking context in the same manner as ORM event hooks + and functions that are invoked via :meth:`.AsyncSession.run_sync`, so + routines that wish to run SQL commands inside of + :meth:`_orm.Session.get_bind` can continue to do so using + blocking-style code, which will be translated to implicitly async calls + at the point of invoking IO on the database drivers. + + + """ # noqa: E501 + + return self._proxied.get_bind( + mapper=mapper, clause=clause, bind=bind, **kw + ) + + def is_modified(self, instance, include_collections=True): + r"""Return ``True`` if the given instance has locally + modified attributes. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This method retrieves the history for each instrumented + attribute on the instance and performs a comparison of the current + value to its previously committed value, if any. + + It is in effect a more expensive and accurate + version of checking for the given instance in the + :attr:`.Session.dirty` collection; a full test for + each attribute's net "dirty" status is performed. + + E.g.:: + + return session.is_modified(someobject) + + A few caveats to this method apply: + + * Instances present in the :attr:`.Session.dirty` collection may + report ``False`` when tested with this method. This is because + the object may have received change events via attribute mutation, + thus placing it in :attr:`.Session.dirty`, but ultimately the state + is the same as that loaded from the database, resulting in no net + change here. + * Scalar attributes may not have recorded the previously set + value when a new value was applied, if the attribute was not loaded, + or was expired, at the time the new value was received - in these + cases, the attribute is assumed to have a change, even if there is + ultimately no net change against its database value. SQLAlchemy in + most cases does not need the "old" value when a set event occurs, so + it skips the expense of a SQL call if the old value isn't present, + based on the assumption that an UPDATE of the scalar value is + usually needed, and in those few cases where it isn't, is less + expensive on average than issuing a defensive SELECT. + + The "old" value is fetched unconditionally upon set only if the + attribute container has the ``active_history`` flag set to ``True``. + This flag is set typically for primary key attributes and scalar + object references that are not a simple many-to-one. To set this + flag for any arbitrary mapped column, use the ``active_history`` + argument with :func:`.column_property`. + + :param instance: mapped instance to be tested for pending changes. + :param include_collections: Indicates if multivalued collections + should be included in the operation. Setting this to ``False`` is a + way to detect only local-column based properties (i.e. scalar columns + or many-to-one foreign keys) that would result in an UPDATE for this + instance upon flush. + + + + """ # noqa: E501 + + return self._proxied.is_modified( + instance, include_collections=include_collections + ) + + async def invalidate(self): + r"""Close this Session, using connection invalidation. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + For a complete description, see :meth:`_orm.Session.invalidate`. + + """ # noqa: E501 + + return await self._proxied.invalidate() + + async def merge(self, instance, load=True, options=None): + r"""Copy the state of a given instance into a corresponding instance + within this :class:`_asyncio.AsyncSession`. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. seealso:: + + :meth:`_orm.Session.merge` - main documentation for merge + + + """ # noqa: E501 + + return await self._proxied.merge(instance, load=load, options=options) + + async def refresh( + self, instance, attribute_names=None, with_for_update=None + ): + r"""Expire and refresh the attributes on the given instance. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + A query will be issued to the database and all attributes will be + refreshed with their current database value. + + This is the async version of the :meth:`_orm.Session.refresh` method. + See that method for a complete description of all options. + + .. seealso:: + + :meth:`_orm.Session.refresh` - main documentation for refresh + + + """ # noqa: E501 + + return await self._proxied.refresh( + instance, + attribute_names=attribute_names, + with_for_update=with_for_update, + ) + + async def rollback(self): + r"""Rollback the current transaction in progress. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + """ # noqa: E501 + + return await self._proxied.rollback() + + async def scalar( + self, + statement, + params=None, + execution_options=util.EMPTY_DICT, + bind_arguments=None, + **kw, + ): + r"""Execute a statement and return a scalar result. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. seealso:: + + :meth:`_orm.Session.scalar` - main documentation for scalar + + + """ # noqa: E501 + + return await self._proxied.scalar( + statement, + params=params, + execution_options=execution_options, + bind_arguments=bind_arguments, + **kw, + ) + + async def scalars( + self, + statement, + params=None, + execution_options=util.EMPTY_DICT, + bind_arguments=None, + **kw, + ): + r"""Execute a statement and return scalar results. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + :return: a :class:`_result.ScalarResult` object + + .. versionadded:: 1.4.24 + + .. seealso:: + + :meth:`_orm.Session.scalars` - main documentation for scalars + + :meth:`_asyncio.AsyncSession.stream_scalars` - streaming version + + + """ # noqa: E501 + + return await self._proxied.scalars( + statement, + params=params, + execution_options=execution_options, + bind_arguments=bind_arguments, + **kw, + ) + + async def stream( + self, + statement, + params=None, + execution_options=util.EMPTY_DICT, + bind_arguments=None, + **kw, + ): + r"""Execute a statement and return a streaming + :class:`_asyncio.AsyncResult` object. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + + """ # noqa: E501 + + return await self._proxied.stream( + statement, + params=params, + execution_options=execution_options, + bind_arguments=bind_arguments, + **kw, + ) + + async def stream_scalars( + self, + statement, + params=None, + execution_options=util.EMPTY_DICT, + bind_arguments=None, + **kw, + ): + r"""Execute a statement and return a stream of scalar results. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + :return: an :class:`_asyncio.AsyncScalarResult` object + + .. versionadded:: 1.4.24 + + .. seealso:: + + :meth:`_orm.Session.scalars` - main documentation for scalars + + :meth:`_asyncio.AsyncSession.scalars` - non streaming version + + + """ # noqa: E501 + + return await self._proxied.stream_scalars( + statement, + params=params, + execution_options=execution_options, + bind_arguments=bind_arguments, + **kw, + ) + + @property + def bind(self) -> Any: + r"""Proxy for the :attr:`_asyncio.AsyncSession.bind` attribute + on behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + """ # noqa: E501 + + return self._proxied.bind + + @bind.setter + def bind(self, attr: Any) -> None: + self._proxied.bind = attr + + @property + def dirty(self) -> Any: + r"""The set of all persistent instances considered dirty. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class + on behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + E.g.:: + + some_mapped_object in session.dirty + + Instances are considered dirty when they were modified but not + deleted. + + Note that this 'dirty' calculation is 'optimistic'; most + attribute-setting or collection modification operations will + mark an instance as 'dirty' and place it in this set, even if + there is no net change to the attribute's value. At flush + time, the value of each attribute is compared to its + previously saved value, and if there's no net change, no SQL + operation will occur (this is a more expensive operation so + it's only done at flush time). + + To check if an instance has actionable net changes to its + attributes, use the :meth:`.Session.is_modified` method. + + + + """ # noqa: E501 + + return self._proxied.dirty + + @property + def deleted(self) -> Any: + r"""The set of all instances marked as 'deleted' within this ``Session`` + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class + on behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + + """ # noqa: E501 + + return self._proxied.deleted + + @property + def new(self) -> Any: + r"""The set of all instances marked as 'new' within this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class + on behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + + """ # noqa: E501 + + return self._proxied.new + + @property + def identity_map(self) -> Any: + r"""Proxy for the :attr:`_orm.Session.identity_map` attribute + on behalf of the :class:`_asyncio.AsyncSession` class. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class + on behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + + """ # noqa: E501 + + return self._proxied.identity_map + + @identity_map.setter + def identity_map(self, attr: Any) -> None: + self._proxied.identity_map = attr + + @property + def is_active(self) -> Any: + r"""True if this :class:`.Session` not in "partial rollback" state. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class + on behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + .. versionchanged:: 1.4 The :class:`_orm.Session` no longer begins + a new transaction immediately, so this attribute will be False + when the :class:`_orm.Session` is first instantiated. + + "partial rollback" state typically indicates that the flush process + of the :class:`_orm.Session` has failed, and that the + :meth:`_orm.Session.rollback` method must be emitted in order to + fully roll back the transaction. + + If this :class:`_orm.Session` is not in a transaction at all, the + :class:`_orm.Session` will autobegin when it is first used, so in this + case :attr:`_orm.Session.is_active` will return True. + + Otherwise, if this :class:`_orm.Session` is within a transaction, + and that transaction has not been rolled back internally, the + :attr:`_orm.Session.is_active` will also return True. + + .. seealso:: + + :ref:`faq_session_rollback` + + :meth:`_orm.Session.in_transaction` + + + + """ # noqa: E501 + + return self._proxied.is_active + + @property + def autoflush(self) -> Any: + r"""Proxy for the :attr:`_orm.Session.autoflush` attribute + on behalf of the :class:`_asyncio.AsyncSession` class. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class + on behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + + """ # noqa: E501 + + return self._proxied.autoflush + + @autoflush.setter + def autoflush(self, attr: Any) -> None: + self._proxied.autoflush = attr + + @property + def no_autoflush(self) -> Any: + r"""Return a context manager that disables autoflush. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class + on behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + e.g.:: + + with session.no_autoflush: + + some_object = SomeClass() + session.add(some_object) + # won't autoflush + some_object.related_thing = session.query(SomeRelated).first() + + Operations that proceed within the ``with:`` block + will not be subject to flushes occurring upon query + access. This is useful when initializing a series + of objects which involve existing database queries, + where the uncompleted object should not yet be flushed. + + + + """ # noqa: E501 + + return self._proxied.no_autoflush + + @property + def info(self) -> Any: + r"""A user-modifiable dictionary. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class + on behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + The initial value of this dictionary can be populated using the + ``info`` argument to the :class:`.Session` constructor or + :class:`.sessionmaker` constructor or factory methods. The dictionary + here is always local to this :class:`.Session` and can be modified + independently of all other :class:`.Session` objects. + + + + """ # noqa: E501 + + return self._proxied.info + + @classmethod + async def close_all(self): + r"""Close all :class:`_asyncio.AsyncSession` sessions. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + """ # noqa: E501 + + return await AsyncSession.close_all() + + @classmethod + def object_session(cls, instance: Any) -> "Session": + r"""Return the :class:`.Session` to which an object belongs. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This is an alias of :func:`.object_session`. + + + + """ # noqa: E501 + + return AsyncSession.object_session(instance) + + @classmethod + def identity_key( + cls, + class_=None, + ident=None, + *, + instance=None, + row=None, + identity_token=None, + ) -> _IdentityKeyType: + r"""Return an identity key. + + .. container:: class_bases + + Proxied for the :class:`_asyncio.AsyncSession` class on + behalf of the :class:`_asyncio.scoping.async_scoped_session` class. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This is an alias of :func:`.util.identity_key`. + + + + """ # noqa: E501 + + return AsyncSession.identity_key( + class_=class_, + ident=ident, + instance=instance, + row=row, + identity_token=identity_token, + ) + + # END PROXY METHODS async_scoped_session diff --git a/lib/sqlalchemy/ext/asyncio/session.py b/lib/sqlalchemy/ext/asyncio/session.py index c39a8d6e0..0bd2530b2 100644 --- a/lib/sqlalchemy/ext/asyncio/session.py +++ b/lib/sqlalchemy/ext/asyncio/session.py @@ -4,6 +4,10 @@ # # This module is part of SQLAlchemy and is released under # the MIT License: https://www.opensource.org/licenses/mit-license.php +from __future__ import annotations + +from typing import Any + from . import engine from . import result as _result from .base import ReversibleProxy @@ -312,7 +316,9 @@ class AsyncSession(ReversibleProxy): **kw, ): """Execute a statement and return a streaming - :class:`_asyncio.AsyncResult` object.""" + :class:`_asyncio.AsyncResult` object. + + """ if execution_options: execution_options = util.immutabledict(execution_options).union( @@ -629,6 +635,508 @@ class AsyncSession(ReversibleProxy): # TODO: can this use asynccontextmanager ?? return _AsyncSessionContextManager(self) + # START PROXY METHODS AsyncSession + + # code within this block is **programmatically, + # statically generated** by tools/generate_proxy_methods.py + + def __contains__(self, instance): + r"""Return True if the instance is associated with this session. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + The instance may be pending or persistent within the Session for a + result of True. + + + """ # noqa: E501 + + return self._proxied.__contains__(instance) + + def __iter__(self): + r"""Iterate over all pending or persistent instances within this + Session. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + + """ # noqa: E501 + + return self._proxied.__iter__() + + def add(self, instance: Any, _warn: bool = True) -> None: + r"""Place an object in the ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + Its state will be persisted to the database on the next flush + operation. + + Repeated calls to ``add()`` will be ignored. The opposite of ``add()`` + is ``expunge()``. + + + """ # noqa: E501 + + return self._proxied.add(instance, _warn=_warn) + + def add_all(self, instances): + r"""Add the given collection of instances to this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + """ # noqa: E501 + + return self._proxied.add_all(instances) + + def expire(self, instance, attribute_names=None): + r"""Expire the attributes on an instance. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + Marks the attributes of an instance as out of date. When an expired + attribute is next accessed, a query will be issued to the + :class:`.Session` object's current transactional context in order to + load all expired attributes for the given instance. Note that + a highly isolated transaction will return the same values as were + previously read in that same transaction, regardless of changes + in database state outside of that transaction. + + To expire all objects in the :class:`.Session` simultaneously, + use :meth:`Session.expire_all`. + + The :class:`.Session` object's default behavior is to + expire all state whenever the :meth:`Session.rollback` + or :meth:`Session.commit` methods are called, so that new + state can be loaded for the new transaction. For this reason, + calling :meth:`Session.expire` only makes sense for the specific + case that a non-ORM SQL statement was emitted in the current + transaction. + + :param instance: The instance to be refreshed. + :param attribute_names: optional list of string attribute names + indicating a subset of attributes to be expired. + + .. seealso:: + + :ref:`session_expire` - introductory material + + :meth:`.Session.expire` + + :meth:`.Session.refresh` + + :meth:`_orm.Query.populate_existing` + + + """ # noqa: E501 + + return self._proxied.expire(instance, attribute_names=attribute_names) + + def expire_all(self): + r"""Expires all persistent instances within this Session. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + When any attributes on a persistent instance is next accessed, + a query will be issued using the + :class:`.Session` object's current transactional context in order to + load all expired attributes for the given instance. Note that + a highly isolated transaction will return the same values as were + previously read in that same transaction, regardless of changes + in database state outside of that transaction. + + To expire individual objects and individual attributes + on those objects, use :meth:`Session.expire`. + + The :class:`.Session` object's default behavior is to + expire all state whenever the :meth:`Session.rollback` + or :meth:`Session.commit` methods are called, so that new + state can be loaded for the new transaction. For this reason, + calling :meth:`Session.expire_all` is not usually needed, + assuming the transaction is isolated. + + .. seealso:: + + :ref:`session_expire` - introductory material + + :meth:`.Session.expire` + + :meth:`.Session.refresh` + + :meth:`_orm.Query.populate_existing` + + + """ # noqa: E501 + + return self._proxied.expire_all() + + def expunge(self, instance): + r"""Remove the `instance` from this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This will free all internal references to the instance. Cascading + will be applied according to the *expunge* cascade rule. + + + """ # noqa: E501 + + return self._proxied.expunge(instance) + + def expunge_all(self): + r"""Remove all object instances from this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This is equivalent to calling ``expunge(obj)`` on all objects in this + ``Session``. + + + """ # noqa: E501 + + return self._proxied.expunge_all() + + def is_modified(self, instance, include_collections=True): + r"""Return ``True`` if the given instance has locally + modified attributes. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This method retrieves the history for each instrumented + attribute on the instance and performs a comparison of the current + value to its previously committed value, if any. + + It is in effect a more expensive and accurate + version of checking for the given instance in the + :attr:`.Session.dirty` collection; a full test for + each attribute's net "dirty" status is performed. + + E.g.:: + + return session.is_modified(someobject) + + A few caveats to this method apply: + + * Instances present in the :attr:`.Session.dirty` collection may + report ``False`` when tested with this method. This is because + the object may have received change events via attribute mutation, + thus placing it in :attr:`.Session.dirty`, but ultimately the state + is the same as that loaded from the database, resulting in no net + change here. + * Scalar attributes may not have recorded the previously set + value when a new value was applied, if the attribute was not loaded, + or was expired, at the time the new value was received - in these + cases, the attribute is assumed to have a change, even if there is + ultimately no net change against its database value. SQLAlchemy in + most cases does not need the "old" value when a set event occurs, so + it skips the expense of a SQL call if the old value isn't present, + based on the assumption that an UPDATE of the scalar value is + usually needed, and in those few cases where it isn't, is less + expensive on average than issuing a defensive SELECT. + + The "old" value is fetched unconditionally upon set only if the + attribute container has the ``active_history`` flag set to ``True``. + This flag is set typically for primary key attributes and scalar + object references that are not a simple many-to-one. To set this + flag for any arbitrary mapped column, use the ``active_history`` + argument with :func:`.column_property`. + + :param instance: mapped instance to be tested for pending changes. + :param include_collections: Indicates if multivalued collections + should be included in the operation. Setting this to ``False`` is a + way to detect only local-column based properties (i.e. scalar columns + or many-to-one foreign keys) that would result in an UPDATE for this + instance upon flush. + + + """ # noqa: E501 + + return self._proxied.is_modified( + instance, include_collections=include_collections + ) + + def in_transaction(self): + r"""Return True if this :class:`_orm.Session` has begun a transaction. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + .. versionadded:: 1.4 + + .. seealso:: + + :attr:`_orm.Session.is_active` + + + + """ # noqa: E501 + + return self._proxied.in_transaction() + + def in_nested_transaction(self): + r"""Return True if this :class:`_orm.Session` has begun a nested + transaction, e.g. SAVEPOINT. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + .. versionadded:: 1.4 + + + """ # noqa: E501 + + return self._proxied.in_nested_transaction() + + @property + def dirty(self) -> Any: + r"""The set of all persistent instances considered dirty. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + E.g.:: + + some_mapped_object in session.dirty + + Instances are considered dirty when they were modified but not + deleted. + + Note that this 'dirty' calculation is 'optimistic'; most + attribute-setting or collection modification operations will + mark an instance as 'dirty' and place it in this set, even if + there is no net change to the attribute's value. At flush + time, the value of each attribute is compared to its + previously saved value, and if there's no net change, no SQL + operation will occur (this is a more expensive operation so + it's only done at flush time). + + To check if an instance has actionable net changes to its + attributes, use the :meth:`.Session.is_modified` method. + + + """ # noqa: E501 + + return self._proxied.dirty + + @property + def deleted(self) -> Any: + r"""The set of all instances marked as 'deleted' within this ``Session`` + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + """ # noqa: E501 + + return self._proxied.deleted + + @property + def new(self) -> Any: + r"""The set of all instances marked as 'new' within this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + """ # noqa: E501 + + return self._proxied.new + + @property + def identity_map(self) -> identity.IdentityMap: + r"""Proxy for the :attr:`_orm.Session.identity_map` attribute + on behalf of the :class:`_asyncio.AsyncSession` class. + + """ # noqa: E501 + + return self._proxied.identity_map + + @identity_map.setter + def identity_map(self, attr: identity.IdentityMap) -> None: + self._proxied.identity_map = attr + + @property + def is_active(self) -> Any: + r"""True if this :class:`.Session` not in "partial rollback" state. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + .. versionchanged:: 1.4 The :class:`_orm.Session` no longer begins + a new transaction immediately, so this attribute will be False + when the :class:`_orm.Session` is first instantiated. + + "partial rollback" state typically indicates that the flush process + of the :class:`_orm.Session` has failed, and that the + :meth:`_orm.Session.rollback` method must be emitted in order to + fully roll back the transaction. + + If this :class:`_orm.Session` is not in a transaction at all, the + :class:`_orm.Session` will autobegin when it is first used, so in this + case :attr:`_orm.Session.is_active` will return True. + + Otherwise, if this :class:`_orm.Session` is within a transaction, + and that transaction has not been rolled back internally, the + :attr:`_orm.Session.is_active` will also return True. + + .. seealso:: + + :ref:`faq_session_rollback` + + :meth:`_orm.Session.in_transaction` + + + """ # noqa: E501 + + return self._proxied.is_active + + @property + def autoflush(self) -> bool: + r"""Proxy for the :attr:`_orm.Session.autoflush` attribute + on behalf of the :class:`_asyncio.AsyncSession` class. + + """ # noqa: E501 + + return self._proxied.autoflush + + @autoflush.setter + def autoflush(self, attr: bool) -> None: + self._proxied.autoflush = attr + + @property + def no_autoflush(self) -> Any: + r"""Return a context manager that disables autoflush. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + e.g.:: + + with session.no_autoflush: + + some_object = SomeClass() + session.add(some_object) + # won't autoflush + some_object.related_thing = session.query(SomeRelated).first() + + Operations that proceed within the ``with:`` block + will not be subject to flushes occurring upon query + access. This is useful when initializing a series + of objects which involve existing database queries, + where the uncompleted object should not yet be flushed. + + + """ # noqa: E501 + + return self._proxied.no_autoflush + + @property + def info(self) -> Any: + r"""A user-modifiable dictionary. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_asyncio.AsyncSession` class. + + The initial value of this dictionary can be populated using the + ``info`` argument to the :class:`.Session` constructor or + :class:`.sessionmaker` constructor or factory methods. The dictionary + here is always local to this :class:`.Session` and can be modified + independently of all other :class:`.Session` objects. + + + """ # noqa: E501 + + return self._proxied.info + + @classmethod + def object_session(cls, instance: Any) -> "Session": + r"""Return the :class:`.Session` to which an object belongs. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This is an alias of :func:`.object_session`. + + + """ # noqa: E501 + + return Session.object_session(instance) + + @classmethod + def identity_key( + cls, + class_=None, + ident=None, + *, + instance=None, + row=None, + identity_token=None, + ) -> _IdentityKeyType: + r"""Return an identity key. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_asyncio.AsyncSession` class. + + This is an alias of :func:`.util.identity_key`. + + + """ # noqa: E501 + + return Session.identity_key( + class_=class_, + ident=ident, + instance=instance, + row=row, + identity_token=identity_token, + ) + + # END PROXY METHODS AsyncSession + class _AsyncSessionContextManager: def __init__(self, async_session): diff --git a/lib/sqlalchemy/orm/scoping.py b/lib/sqlalchemy/orm/scoping.py index 9eb80a107..cc9d5a23b 100644 --- a/lib/sqlalchemy/orm/scoping.py +++ b/lib/sqlalchemy/orm/scoping.py @@ -11,6 +11,7 @@ from . import exc as orm_exc from .base import class_mapper from .session import Session from .. import exc as sa_exc +from .. import util from ..util import create_proxy_methods from ..util import ScopedRegistry from ..util import ThreadLocalRegistry @@ -225,6 +226,1582 @@ class scoped_session(ScopedSessionMixin): return query() + # START PROXY METHODS scoped_session + + # code within this block is **programmatically, + # statically generated** by tools/generate_proxy_methods.py + + def __contains__(self, instance): + r"""Return True if the instance is associated with this session. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + The instance may be pending or persistent within the Session for a + result of True. + + + """ # noqa: E501 + + return self._proxied.__contains__(instance) + + def __iter__(self): + r"""Iterate over all pending or persistent instances within this + Session. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + + """ # noqa: E501 + + return self._proxied.__iter__() + + def add(self, instance: Any, _warn: bool = True) -> None: + r"""Place an object in the ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + Its state will be persisted to the database on the next flush + operation. + + Repeated calls to ``add()`` will be ignored. The opposite of ``add()`` + is ``expunge()``. + + + """ # noqa: E501 + + return self._proxied.add(instance, _warn=_warn) + + def add_all(self, instances): + r"""Add the given collection of instances to this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + """ # noqa: E501 + + return self._proxied.add_all(instances) + + def begin(self, nested=False, _subtrans=False): + r"""Begin a transaction, or nested transaction, + on this :class:`.Session`, if one is not already begun. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + The :class:`_orm.Session` object features **autobegin** behavior, + so that normally it is not necessary to call the + :meth:`_orm.Session.begin` + method explicitly. However, it may be used in order to control + the scope of when the transactional state is begun. + + When used to begin the outermost transaction, an error is raised + if this :class:`.Session` is already inside of a transaction. + + :param nested: if True, begins a SAVEPOINT transaction and is + equivalent to calling :meth:`~.Session.begin_nested`. For + documentation on SAVEPOINT transactions, please see + :ref:`session_begin_nested`. + + :return: the :class:`.SessionTransaction` object. Note that + :class:`.SessionTransaction` + acts as a Python context manager, allowing :meth:`.Session.begin` + to be used in a "with" block. See :ref:`session_explicit_begin` for + an example. + + .. seealso:: + + :ref:`session_autobegin` + + :ref:`unitofwork_transaction` + + :meth:`.Session.begin_nested` + + + + """ # noqa: E501 + + return self._proxied.begin(nested=nested, _subtrans=_subtrans) + + def begin_nested(self): + r"""Begin a "nested" transaction on this Session, e.g. SAVEPOINT. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + 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. + + + """ # noqa: E501 + + return self._proxied.begin_nested() + + def close(self): + r"""Close out the transactional resources and ORM objects used by this + :class:`_orm.Session`. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + This expunges all ORM objects associated with this + :class:`_orm.Session`, ends any transaction in progress and + :term:`releases` any :class:`_engine.Connection` objects which this + :class:`_orm.Session` itself has checked out from associated + :class:`_engine.Engine` objects. The operation then leaves the + :class:`_orm.Session` in a state which it may be used again. + + .. tip:: + + The :meth:`_orm.Session.close` method **does not prevent the + Session from being used again**. The :class:`_orm.Session` itself + does not actually have a distinct "closed" state; it merely means + the :class:`_orm.Session` will release all database connections + and ORM objects. + + .. versionchanged:: 1.4 The :meth:`.Session.close` method does not + immediately create a new :class:`.SessionTransaction` object; + instead, the new :class:`.SessionTransaction` is created only if + the :class:`.Session` is used again for a database operation. + + .. seealso:: + + :ref:`session_closing` - detail on the semantics of + :meth:`_orm.Session.close` + + + """ # noqa: E501 + + return self._proxied.close() + + def commit(self) -> None: + r"""Flush pending changes and commit the current transaction. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + If no transaction is in progress, the method will first + "autobegin" a new transaction and commit. + + The outermost database transaction is committed unconditionally, + automatically releasing any SAVEPOINTs in effect. + + .. seealso:: + + :ref:`session_committing` + + :ref:`unitofwork_transaction` + + + """ # noqa: E501 + + return self._proxied.commit() + + def connection( + self, + bind_arguments: Optional[Dict[str, Any]] = None, + execution_options: Optional["_ExecuteOptions"] = None, + ) -> "Connection": + r"""Return a :class:`_engine.Connection` object corresponding to this + :class:`.Session` object's transactional state. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + Either the :class:`_engine.Connection` corresponding to the current + transaction is returned, or if no transaction is in progress, a new + one is begun and the :class:`_engine.Connection` + returned (note that no + transactional state is established with the DBAPI until the first + SQL statement is emitted). + + Ambiguity in multi-bind or unbound :class:`.Session` objects can be + resolved through any of the optional keyword arguments. This + ultimately makes usage of the :meth:`.get_bind` method for resolution. + + :param bind_arguments: dictionary of bind arguments. May include + "mapper", "bind", "clause", other custom arguments that are passed + to :meth:`.Session.get_bind`. + + :param execution_options: a dictionary of execution options that will + be passed to :meth:`_engine.Connection.execution_options`, **when the + connection is first procured only**. If the connection is already + present within the :class:`.Session`, a warning is emitted and + the arguments are ignored. + + .. seealso:: + + :ref:`session_transaction_isolation` + + + """ # noqa: E501 + + return self._proxied.connection( + bind_arguments=bind_arguments, execution_options=execution_options + ) + + def delete(self, instance): + r"""Mark an instance as deleted. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + The database delete operation occurs upon ``flush()``. + + + """ # noqa: E501 + + return self._proxied.delete(instance) + + def execute( + self, + statement: "Executable", + params: Optional["_ExecuteParams"] = None, + execution_options: "_ExecuteOptions" = util.EMPTY_DICT, + bind_arguments: Optional[Dict[str, Any]] = None, + _parent_execute_state: Optional[Any] = None, + _add_event: Optional[Any] = None, + ): + r"""Execute a SQL expression construct. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + Returns a :class:`_engine.Result` object representing + results of the statement execution. + + E.g.:: + + from sqlalchemy import select + result = session.execute( + select(User).where(User.id == 5) + ) + + The API contract of :meth:`_orm.Session.execute` is similar to that + of :meth:`_engine.Connection.execute`, the :term:`2.0 style` version + of :class:`_engine.Connection`. + + .. versionchanged:: 1.4 the :meth:`_orm.Session.execute` method is + now the primary point of ORM statement execution when using + :term:`2.0 style` ORM usage. + + :param statement: + An executable statement (i.e. an :class:`.Executable` expression + such as :func:`_expression.select`). + + :param params: + Optional dictionary, or list of dictionaries, containing + bound parameter values. If a single dictionary, single-row + execution occurs; if a list of dictionaries, an + "executemany" will be invoked. The keys in each dictionary + must correspond to parameter names present in the statement. + + :param execution_options: optional dictionary of execution options, + which will be associated with the statement execution. This + dictionary can provide a subset of the options that are accepted + by :meth:`_engine.Connection.execution_options`, and may also + provide additional options understood only in an ORM context. + + .. seealso:: + + :ref:`orm_queryguide_execution_options` - ORM-specific execution + options + + :param bind_arguments: dictionary of additional arguments to determine + the bind. May include "mapper", "bind", or other custom arguments. + Contents of this dictionary are passed to the + :meth:`.Session.get_bind` method. + + :return: a :class:`_engine.Result` object. + + + + """ # noqa: E501 + + return self._proxied.execute( + statement, + params=params, + execution_options=execution_options, + bind_arguments=bind_arguments, + _parent_execute_state=_parent_execute_state, + _add_event=_add_event, + ) + + def expire(self, instance, attribute_names=None): + r"""Expire the attributes on an instance. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + Marks the attributes of an instance as out of date. When an expired + attribute is next accessed, a query will be issued to the + :class:`.Session` object's current transactional context in order to + load all expired attributes for the given instance. Note that + a highly isolated transaction will return the same values as were + previously read in that same transaction, regardless of changes + in database state outside of that transaction. + + To expire all objects in the :class:`.Session` simultaneously, + use :meth:`Session.expire_all`. + + The :class:`.Session` object's default behavior is to + expire all state whenever the :meth:`Session.rollback` + or :meth:`Session.commit` methods are called, so that new + state can be loaded for the new transaction. For this reason, + calling :meth:`Session.expire` only makes sense for the specific + case that a non-ORM SQL statement was emitted in the current + transaction. + + :param instance: The instance to be refreshed. + :param attribute_names: optional list of string attribute names + indicating a subset of attributes to be expired. + + .. seealso:: + + :ref:`session_expire` - introductory material + + :meth:`.Session.expire` + + :meth:`.Session.refresh` + + :meth:`_orm.Query.populate_existing` + + + """ # noqa: E501 + + return self._proxied.expire(instance, attribute_names=attribute_names) + + def expire_all(self): + r"""Expires all persistent instances within this Session. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + When any attributes on a persistent instance is next accessed, + a query will be issued using the + :class:`.Session` object's current transactional context in order to + load all expired attributes for the given instance. Note that + a highly isolated transaction will return the same values as were + previously read in that same transaction, regardless of changes + in database state outside of that transaction. + + To expire individual objects and individual attributes + on those objects, use :meth:`Session.expire`. + + The :class:`.Session` object's default behavior is to + expire all state whenever the :meth:`Session.rollback` + or :meth:`Session.commit` methods are called, so that new + state can be loaded for the new transaction. For this reason, + calling :meth:`Session.expire_all` is not usually needed, + assuming the transaction is isolated. + + .. seealso:: + + :ref:`session_expire` - introductory material + + :meth:`.Session.expire` + + :meth:`.Session.refresh` + + :meth:`_orm.Query.populate_existing` + + + """ # noqa: E501 + + return self._proxied.expire_all() + + def expunge(self, instance): + r"""Remove the `instance` from this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + This will free all internal references to the instance. Cascading + will be applied according to the *expunge* cascade rule. + + + """ # noqa: E501 + + return self._proxied.expunge(instance) + + def expunge_all(self): + r"""Remove all object instances from this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + This is equivalent to calling ``expunge(obj)`` on all objects in this + ``Session``. + + + """ # noqa: E501 + + return self._proxied.expunge_all() + + def flush(self, objects=None): + r"""Flush all the object changes to the database. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + Writes out all pending object creations, deletions and modifications + to the database as INSERTs, DELETEs, UPDATEs, etc. Operations are + automatically ordered by the Session's unit of work dependency + solver. + + Database operations will be issued in the current transactional + context and do not affect the state of the transaction, unless an + error occurs, in which case the entire transaction is rolled back. + You may flush() as often as you like within a transaction to move + changes from Python to the database's transaction buffer. + + :param objects: Optional; restricts the flush operation to operate + only on elements that are in the given collection. + + This feature is for an extremely narrow set of use cases where + particular objects may need to be operated upon before the + full flush() occurs. It is not intended for general use. + + + """ # noqa: E501 + + return self._proxied.flush(objects=objects) + + def get( + self, + entity, + ident, + options=None, + populate_existing=False, + with_for_update=None, + identity_token=None, + execution_options=None, + ): + r"""Return an instance based on the given primary key identifier, + or ``None`` if not found. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + E.g.:: + + my_user = session.get(User, 5) + + some_object = session.get(VersionedFoo, (5, 10)) + + some_object = session.get( + VersionedFoo, + {"id": 5, "version_id": 10} + ) + + .. versionadded:: 1.4 Added :meth:`_orm.Session.get`, which is moved + from the now legacy :meth:`_orm.Query.get` method. + + :meth:`_orm.Session.get` is special in that it provides direct + access to the identity map of the :class:`.Session`. + If the given primary key identifier is present + in the local identity map, the object is returned + directly from this collection and no SQL is emitted, + unless the object has been marked fully expired. + If not present, + a SELECT is performed in order to locate the object. + + :meth:`_orm.Session.get` also will perform a check if + the object is present in the identity map and + marked as expired - a SELECT + is emitted to refresh the object as well as to + ensure that the row is still present. + If not, :class:`~sqlalchemy.orm.exc.ObjectDeletedError` is raised. + + :param entity: a mapped class or :class:`.Mapper` indicating the + type of entity to be loaded. + + :param ident: A scalar, tuple, or dictionary representing the + primary key. For a composite (e.g. multiple column) primary key, + a tuple or dictionary should be passed. + + For a single-column primary key, the scalar calling form is typically + the most expedient. If the primary key of a row is the value "5", + the call looks like:: + + my_object = session.get(SomeClass, 5) + + The tuple form contains primary key values typically in + the order in which they correspond to the mapped + :class:`_schema.Table` + object's primary key columns, or if the + :paramref:`_orm.Mapper.primary_key` configuration parameter were + used, in + the order used for that parameter. For example, if the primary key + of a row is represented by the integer + digits "5, 10" the call would look like:: + + my_object = session.get(SomeClass, (5, 10)) + + The dictionary form should include as keys the mapped attribute names + corresponding to each element of the primary key. If the mapped class + has the attributes ``id``, ``version_id`` as the attributes which + store the object's primary key value, the call would look like:: + + my_object = session.get(SomeClass, {"id": 5, "version_id": 10}) + + :param options: optional sequence of loader options which will be + applied to the query, if one is emitted. + + :param populate_existing: causes the method to unconditionally emit + a SQL query and refresh the object with the newly loaded data, + regardless of whether or not the object is already present. + + :param with_for_update: optional boolean ``True`` indicating FOR UPDATE + should be used, or may be a dictionary containing flags to + indicate a more specific set of FOR UPDATE flags for the SELECT; + flags should match the parameters of + :meth:`_query.Query.with_for_update`. + Supersedes the :paramref:`.Session.refresh.lockmode` parameter. + + :param execution_options: optional dictionary of execution options, + which will be associated with the query execution if one is emitted. + This dictionary can provide a subset of the options that are + accepted by :meth:`_engine.Connection.execution_options`, and may + also provide additional options understood only in an ORM context. + + .. versionadded:: 1.4.29 + + .. seealso:: + + :ref:`orm_queryguide_execution_options` - ORM-specific execution + options + + :return: The object instance, or ``None``. + + + """ # noqa: E501 + + return self._proxied.get( + entity, + ident, + options=options, + populate_existing=populate_existing, + with_for_update=with_for_update, + identity_token=identity_token, + execution_options=execution_options, + ) + + def get_bind( + self, + mapper=None, + clause=None, + bind=None, + _sa_skip_events=None, + _sa_skip_for_implicit_returning=False, + ): + r"""Return a "bind" to which this :class:`.Session` is bound. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + The "bind" is usually an instance of :class:`_engine.Engine`, + except in the case where the :class:`.Session` has been + explicitly bound directly to a :class:`_engine.Connection`. + + For a multiply-bound or unbound :class:`.Session`, the + ``mapper`` or ``clause`` arguments are used to determine the + appropriate bind to return. + + Note that the "mapper" argument is usually present + when :meth:`.Session.get_bind` is called via an ORM + operation such as a :meth:`.Session.query`, each + individual INSERT/UPDATE/DELETE operation within a + :meth:`.Session.flush`, call, etc. + + The order of resolution is: + + 1. if mapper given and :paramref:`.Session.binds` is present, + locate a bind based first on the mapper in use, then + on the mapped class in use, then on any base classes that are + present in the ``__mro__`` of the mapped class, from more specific + superclasses to more general. + 2. if clause given and ``Session.binds`` is present, + locate a bind based on :class:`_schema.Table` objects + found in the given clause present in ``Session.binds``. + 3. if ``Session.binds`` is present, return that. + 4. if clause given, attempt to return a bind + linked to the :class:`_schema.MetaData` ultimately + associated with the clause. + 5. if mapper given, attempt to return a bind + linked to the :class:`_schema.MetaData` ultimately + associated with the :class:`_schema.Table` or other + selectable to which the mapper is mapped. + 6. No bind can be found, :exc:`~sqlalchemy.exc.UnboundExecutionError` + is raised. + + Note that the :meth:`.Session.get_bind` method can be overridden on + a user-defined subclass of :class:`.Session` to provide any kind + of bind resolution scheme. See the example at + :ref:`session_custom_partitioning`. + + :param mapper: + Optional mapped class or corresponding :class:`_orm.Mapper` instance. + The bind can be derived from a :class:`_orm.Mapper` first by + consulting the "binds" map associated with this :class:`.Session`, + and secondly by consulting the :class:`_schema.MetaData` associated + with the :class:`_schema.Table` to which the :class:`_orm.Mapper` is + mapped for a bind. + + :param clause: + A :class:`_expression.ClauseElement` (i.e. + :func:`_expression.select`, + :func:`_expression.text`, + etc.). If the ``mapper`` argument is not present or could not + produce a bind, the given expression construct will be searched + for a bound element, typically a :class:`_schema.Table` + associated with + bound :class:`_schema.MetaData`. + + .. seealso:: + + :ref:`session_partitioning` + + :paramref:`.Session.binds` + + :meth:`.Session.bind_mapper` + + :meth:`.Session.bind_table` + + + """ # noqa: E501 + + return self._proxied.get_bind( + mapper=mapper, + clause=clause, + bind=bind, + _sa_skip_events=_sa_skip_events, + _sa_skip_for_implicit_returning=_sa_skip_for_implicit_returning, + ) + + def is_modified(self, instance, include_collections=True): + r"""Return ``True`` if the given instance has locally + modified attributes. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + This method retrieves the history for each instrumented + attribute on the instance and performs a comparison of the current + value to its previously committed value, if any. + + It is in effect a more expensive and accurate + version of checking for the given instance in the + :attr:`.Session.dirty` collection; a full test for + each attribute's net "dirty" status is performed. + + E.g.:: + + return session.is_modified(someobject) + + A few caveats to this method apply: + + * Instances present in the :attr:`.Session.dirty` collection may + report ``False`` when tested with this method. This is because + the object may have received change events via attribute mutation, + thus placing it in :attr:`.Session.dirty`, but ultimately the state + is the same as that loaded from the database, resulting in no net + change here. + * Scalar attributes may not have recorded the previously set + value when a new value was applied, if the attribute was not loaded, + or was expired, at the time the new value was received - in these + cases, the attribute is assumed to have a change, even if there is + ultimately no net change against its database value. SQLAlchemy in + most cases does not need the "old" value when a set event occurs, so + it skips the expense of a SQL call if the old value isn't present, + based on the assumption that an UPDATE of the scalar value is + usually needed, and in those few cases where it isn't, is less + expensive on average than issuing a defensive SELECT. + + The "old" value is fetched unconditionally upon set only if the + attribute container has the ``active_history`` flag set to ``True``. + This flag is set typically for primary key attributes and scalar + object references that are not a simple many-to-one. To set this + flag for any arbitrary mapped column, use the ``active_history`` + argument with :func:`.column_property`. + + :param instance: mapped instance to be tested for pending changes. + :param include_collections: Indicates if multivalued collections + should be included in the operation. Setting this to ``False`` is a + way to detect only local-column based properties (i.e. scalar columns + or many-to-one foreign keys) that would result in an UPDATE for this + instance upon flush. + + + """ # noqa: E501 + + return self._proxied.is_modified( + instance, include_collections=include_collections + ) + + def bulk_save_objects( + self, + objects, + return_defaults=False, + update_changed_only=True, + preserve_order=True, + ): + r"""Perform a bulk save of the given list of objects. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + The bulk save feature allows mapped objects to be used as the + source of simple INSERT and UPDATE operations which can be more easily + grouped together into higher performing "executemany" + operations; the extraction of data from the objects is also performed + using a lower-latency process that ignores whether or not attributes + have actually been modified in the case of UPDATEs, and also ignores + SQL expressions. + + The objects as given are not added to the session and no additional + state is established on them. If the + :paramref:`_orm.Session.bulk_save_objects.return_defaults` flag is set, + then server-generated primary key values will be assigned to the + returned objects, but **not server side defaults**; this is a + limitation in the implementation. If stateful objects are desired, + please use the standard :meth:`_orm.Session.add_all` approach or + as an alternative newer mass-insert features such as + :ref:`orm_dml_returning_objects`. + + .. warning:: + + The bulk save feature allows for a lower-latency INSERT/UPDATE + of rows at the expense of most other unit-of-work features. + Features such as object management, relationship handling, + and SQL clause support are **silently omitted** in favor of raw + INSERT/UPDATES of records. + + Please note that newer versions of SQLAlchemy are **greatly + improving the efficiency** of the standard flush process. It is + **strongly recommended** to not use the bulk methods as they + represent a forking of SQLAlchemy's functionality and are slowly + being moved into legacy status. New features such as + :ref:`orm_dml_returning_objects` are both more efficient than + the "bulk" methods and provide more predictable functionality. + + **Please read the list of caveats at** + :ref:`bulk_operations_caveats` **before using this method, and + fully test and confirm the functionality of all code developed + using these systems.** + + :param objects: a sequence of mapped object instances. The mapped + objects are persisted as is, and are **not** associated with the + :class:`.Session` afterwards. + + For each object, whether the object is sent as an INSERT or an + UPDATE is dependent on the same rules used by the :class:`.Session` + in traditional operation; if the object has the + :attr:`.InstanceState.key` + attribute set, then the object is assumed to be "detached" and + will result in an UPDATE. Otherwise, an INSERT is used. + + In the case of an UPDATE, statements are grouped based on which + attributes have changed, and are thus to be the subject of each + SET clause. If ``update_changed_only`` is False, then all + attributes present within each object are applied to the UPDATE + statement, which may help in allowing the statements to be grouped + together into a larger executemany(), and will also reduce the + overhead of checking history on attributes. + + :param return_defaults: when True, rows that are missing values which + generate defaults, namely integer primary key defaults and sequences, + will be inserted **one at a time**, so that the primary key value + is available. In particular this will allow joined-inheritance + and other multi-table mappings to insert correctly without the need + to provide primary key values ahead of time; however, + :paramref:`.Session.bulk_save_objects.return_defaults` **greatly + reduces the performance gains** of the method overall. It is strongly + advised to please use the standard :meth:`_orm.Session.add_all` + approach. + + :param update_changed_only: when True, UPDATE statements are rendered + based on those attributes in each state that have logged changes. + When False, all attributes present are rendered into the SET clause + with the exception of primary key attributes. + + :param preserve_order: when True, the order of inserts and updates + matches exactly the order in which the objects are given. When + False, common types of objects are grouped into inserts + and updates, to allow for more batching opportunities. + + .. versionadded:: 1.3 + + .. seealso:: + + :ref:`bulk_operations` + + :meth:`.Session.bulk_insert_mappings` + + :meth:`.Session.bulk_update_mappings` + + + """ # noqa: E501 + + return self._proxied.bulk_save_objects( + objects, + return_defaults=return_defaults, + update_changed_only=update_changed_only, + preserve_order=preserve_order, + ) + + def bulk_insert_mappings( + self, mapper, mappings, return_defaults=False, render_nulls=False + ): + r"""Perform a bulk insert of the given list of mapping dictionaries. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + The bulk insert feature allows plain Python dictionaries to be used as + the source of simple INSERT operations which can be more easily + grouped together into higher performing "executemany" + operations. Using dictionaries, there is no "history" or session + state management features in use, reducing latency when inserting + large numbers of simple rows. + + The values within the dictionaries as given are typically passed + without modification into Core :meth:`_expression.Insert` constructs, + after + organizing the values within them across the tables to which + the given mapper is mapped. + + .. versionadded:: 1.0.0 + + .. warning:: + + The bulk insert feature allows for a lower-latency INSERT + of rows at the expense of most other unit-of-work features. + Features such as object management, relationship handling, + and SQL clause support are **silently omitted** in favor of raw + INSERT of records. + + Please note that newer versions of SQLAlchemy are **greatly + improving the efficiency** of the standard flush process. It is + **strongly recommended** to not use the bulk methods as they + represent a forking of SQLAlchemy's functionality and are slowly + being moved into legacy status. New features such as + :ref:`orm_dml_returning_objects` are both more efficient than + the "bulk" methods and provide more predictable functionality. + + **Please read the list of caveats at** + :ref:`bulk_operations_caveats` **before using this method, and + fully test and confirm the functionality of all code developed + using these systems.** + + :param mapper: a mapped class, or the actual :class:`_orm.Mapper` + object, + representing the single kind of object represented within the mapping + list. + + :param mappings: a sequence of dictionaries, each one containing the + state of the mapped row to be inserted, in terms of the attribute + names on the mapped class. If the mapping refers to multiple tables, + such as a joined-inheritance mapping, each dictionary must contain all + keys to be populated into all tables. + + :param return_defaults: when True, rows that are missing values which + generate defaults, namely integer primary key defaults and sequences, + will be inserted **one at a time**, so that the primary key value + is available. In particular this will allow joined-inheritance + and other multi-table mappings to insert correctly without the need + to provide primary + key values ahead of time; however, + :paramref:`.Session.bulk_insert_mappings.return_defaults` + **greatly reduces the performance gains** of the method overall. + If the rows + to be inserted only refer to a single table, then there is no + reason this flag should be set as the returned default information + is not used. + + :param render_nulls: When True, a value of ``None`` will result + in a NULL value being included in the INSERT statement, rather + than the column being omitted from the INSERT. This allows all + the rows being INSERTed to have the identical set of columns which + allows the full set of rows to be batched to the DBAPI. Normally, + each column-set that contains a different combination of NULL values + than the previous row must omit a different series of columns from + the rendered INSERT statement, which means it must be emitted as a + separate statement. By passing this flag, the full set of rows + are guaranteed to be batchable into one batch; the cost however is + that server-side defaults which are invoked by an omitted column will + be skipped, so care must be taken to ensure that these are not + necessary. + + .. warning:: + + When this flag is set, **server side default SQL values will + not be invoked** for those columns that are inserted as NULL; + the NULL value will be sent explicitly. Care must be taken + to ensure that no server-side default functions need to be + invoked for the operation as a whole. + + .. versionadded:: 1.1 + + .. seealso:: + + :ref:`bulk_operations` + + :meth:`.Session.bulk_save_objects` + + :meth:`.Session.bulk_update_mappings` + + + """ # noqa: E501 + + return self._proxied.bulk_insert_mappings( + mapper, + mappings, + return_defaults=return_defaults, + render_nulls=render_nulls, + ) + + def bulk_update_mappings(self, mapper, mappings): + r"""Perform a bulk update of the given list of mapping dictionaries. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + The bulk update feature allows plain Python dictionaries to be used as + the source of simple UPDATE operations which can be more easily + grouped together into higher performing "executemany" + operations. Using dictionaries, there is no "history" or session + state management features in use, reducing latency when updating + large numbers of simple rows. + + .. versionadded:: 1.0.0 + + .. warning:: + + The bulk update feature allows for a lower-latency UPDATE + of rows at the expense of most other unit-of-work features. + Features such as object management, relationship handling, + and SQL clause support are **silently omitted** in favor of raw + UPDATES of records. + + Please note that newer versions of SQLAlchemy are **greatly + improving the efficiency** of the standard flush process. It is + **strongly recommended** to not use the bulk methods as they + represent a forking of SQLAlchemy's functionality and are slowly + being moved into legacy status. New features such as + :ref:`orm_dml_returning_objects` are both more efficient than + the "bulk" methods and provide more predictable functionality. + + **Please read the list of caveats at** + :ref:`bulk_operations_caveats` **before using this method, and + fully test and confirm the functionality of all code developed + using these systems.** + + :param mapper: a mapped class, or the actual :class:`_orm.Mapper` + object, + representing the single kind of object represented within the mapping + list. + + :param mappings: a sequence of dictionaries, each one containing the + state of the mapped row to be updated, in terms of the attribute names + on the mapped class. If the mapping refers to multiple tables, such + as a joined-inheritance mapping, each dictionary may contain keys + corresponding to all tables. All those keys which are present and + are not part of the primary key are applied to the SET clause of the + UPDATE statement; the primary key values, which are required, are + applied to the WHERE clause. + + + .. seealso:: + + :ref:`bulk_operations` + + :meth:`.Session.bulk_insert_mappings` + + :meth:`.Session.bulk_save_objects` + + + """ # noqa: E501 + + return self._proxied.bulk_update_mappings(mapper, mappings) + + def merge(self, instance, load=True, options=None): + r"""Copy the state of a given instance into a corresponding instance + within this :class:`.Session`. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + :meth:`.Session.merge` examines the primary key attributes of the + source instance, and attempts to reconcile it with an instance of the + same primary key in the session. If not found locally, it attempts + to load the object from the database based on primary key, and if + none can be located, creates a new instance. The state of each + attribute on the source instance is then copied to the target + instance. The resulting target instance is then returned by the + method; the original source instance is left unmodified, and + un-associated with the :class:`.Session` if not already. + + This operation cascades to associated instances if the association is + mapped with ``cascade="merge"``. + + See :ref:`unitofwork_merging` for a detailed discussion of merging. + + .. versionchanged:: 1.1 - :meth:`.Session.merge` will now reconcile + pending objects with overlapping primary keys in the same way + as persistent. See :ref:`change_3601` for discussion. + + :param instance: Instance to be merged. + :param load: Boolean, when False, :meth:`.merge` switches into + a "high performance" mode which causes it to forego emitting history + events as well as all database access. This flag is used for + cases such as transferring graphs of objects into a :class:`.Session` + from a second level cache, or to transfer just-loaded objects + into the :class:`.Session` owned by a worker thread or process + without re-querying the database. + + The ``load=False`` use case adds the caveat that the given + object has to be in a "clean" state, that is, has no pending changes + to be flushed - even if the incoming object is detached from any + :class:`.Session`. This is so that when + the merge operation populates local attributes and + cascades to related objects and + collections, the values can be "stamped" onto the + target object as is, without generating any history or attribute + events, and without the need to reconcile the incoming data with + any existing related objects or collections that might not + be loaded. The resulting objects from ``load=False`` are always + produced as "clean", so it is only appropriate that the given objects + should be "clean" as well, else this suggests a mis-use of the + method. + :param options: optional sequence of loader options which will be + applied to the :meth:`_orm.Session.get` method when the merge + operation loads the existing version of the object from the database. + + .. versionadded:: 1.4.24 + + + .. seealso:: + + :func:`.make_transient_to_detached` - provides for an alternative + means of "merging" a single object into the :class:`.Session` + + + """ # noqa: E501 + + return self._proxied.merge(instance, load=load, options=options) + + def query(self, *entities: _ColumnsClauseArgument, **kwargs: Any) -> Query: + r"""Return a new :class:`_query.Query` object corresponding to this + :class:`_orm.Session`. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + Note that the :class:`_query.Query` object is legacy as of + SQLAlchemy 2.0; the :func:`_sql.select` construct is now used + to construct ORM queries. + + .. seealso:: + + :ref:`unified_tutorial` + + :ref:`queryguide_toplevel` + + :ref:`query_api_toplevel` - legacy API doc + + + """ # noqa: E501 + + return self._proxied.query(*entities, **kwargs) + + def refresh(self, instance, attribute_names=None, with_for_update=None): + r"""Expire and refresh attributes on the given instance. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + The selected attributes will first be expired as they would when using + :meth:`_orm.Session.expire`; then a SELECT statement will be issued to + the database to refresh column-oriented attributes with the current + value available in the current transaction. + + :func:`_orm.relationship` oriented attributes will also be immediately + loaded if they were already eagerly loaded on the object, using the + same eager loading strategy that they were loaded with originally. + Unloaded relationship attributes will remain unloaded, as will + relationship attributes that were originally lazy loaded. + + .. versionadded:: 1.4 - the :meth:`_orm.Session.refresh` method + can also refresh eagerly loaded attributes. + + .. tip:: + + While the :meth:`_orm.Session.refresh` method is capable of + refreshing both column and relationship oriented attributes, its + primary focus is on refreshing of local column-oriented attributes + on a single instance. For more open ended "refresh" functionality, + including the ability to refresh the attributes on many objects at + once while having explicit control over relationship loader + strategies, use the + :ref:`populate existing <orm_queryguide_populate_existing>` feature + instead. + + Note that a highly isolated transaction will return the same values as + were previously read in that same transaction, regardless of changes + in database state outside of that transaction. Refreshing + attributes usually only makes sense at the start of a transaction + where database rows have not yet been accessed. + + :param attribute_names: optional. An iterable collection of + string attribute names indicating a subset of attributes to + be refreshed. + + :param with_for_update: optional boolean ``True`` indicating FOR UPDATE + should be used, or may be a dictionary containing flags to + indicate a more specific set of FOR UPDATE flags for the SELECT; + flags should match the parameters of + :meth:`_query.Query.with_for_update`. + Supersedes the :paramref:`.Session.refresh.lockmode` parameter. + + .. seealso:: + + :ref:`session_expire` - introductory material + + :meth:`.Session.expire` + + :meth:`.Session.expire_all` + + :ref:`orm_queryguide_populate_existing` - allows any ORM query + to refresh objects as they would be loaded normally. + + + """ # noqa: E501 + + return self._proxied.refresh( + instance, + attribute_names=attribute_names, + with_for_update=with_for_update, + ) + + def rollback(self): + r"""Rollback the current transaction in progress. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + If no transaction is in progress, this method is a pass-through. + + The method always rolls back + the topmost database transaction, discarding any nested + transactions that may be in progress. + + .. seealso:: + + :ref:`session_rollback` + + :ref:`unitofwork_transaction` + + + """ # noqa: E501 + + return self._proxied.rollback() + + def scalar( + self, + statement, + params=None, + execution_options=util.EMPTY_DICT, + bind_arguments=None, + **kw, + ): + r"""Execute a statement and return a scalar result. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + Usage and parameters are the same as that of + :meth:`_orm.Session.execute`; the return result is a scalar Python + value. + + + """ # noqa: E501 + + return self._proxied.scalar( + statement, + params=params, + execution_options=execution_options, + bind_arguments=bind_arguments, + **kw, + ) + + def scalars( + self, + statement, + params=None, + execution_options=util.EMPTY_DICT, + bind_arguments=None, + **kw, + ): + r"""Execute a statement and return the results as scalars. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + Usage and parameters are the same as that of + :meth:`_orm.Session.execute`; the return result is a + :class:`_result.ScalarResult` filtering object which + will return single elements rather than :class:`_row.Row` objects. + + :return: a :class:`_result.ScalarResult` object + + .. versionadded:: 1.4.24 + + + """ # noqa: E501 + + return self._proxied.scalars( + statement, + params=params, + execution_options=execution_options, + bind_arguments=bind_arguments, + **kw, + ) + + @property + def bind(self) -> Optional[Union[Engine, Connection]]: + r"""Proxy for the :attr:`_orm.Session.bind` attribute + on behalf of the :class:`_orm.scoping.scoped_session` class. + + """ # noqa: E501 + + return self._proxied.bind + + @bind.setter + def bind(self, attr: Optional[Union[Engine, Connection]]) -> None: + self._proxied.bind = attr + + @property + def dirty(self) -> Any: + r"""The set of all persistent instances considered dirty. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_orm.scoping.scoped_session` class. + + E.g.:: + + some_mapped_object in session.dirty + + Instances are considered dirty when they were modified but not + deleted. + + Note that this 'dirty' calculation is 'optimistic'; most + attribute-setting or collection modification operations will + mark an instance as 'dirty' and place it in this set, even if + there is no net change to the attribute's value. At flush + time, the value of each attribute is compared to its + previously saved value, and if there's no net change, no SQL + operation will occur (this is a more expensive operation so + it's only done at flush time). + + To check if an instance has actionable net changes to its + attributes, use the :meth:`.Session.is_modified` method. + + + """ # noqa: E501 + + return self._proxied.dirty + + @property + def deleted(self) -> Any: + r"""The set of all instances marked as 'deleted' within this ``Session`` + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_orm.scoping.scoped_session` class. + + """ # noqa: E501 + + return self._proxied.deleted + + @property + def new(self) -> Any: + r"""The set of all instances marked as 'new' within this ``Session``. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_orm.scoping.scoped_session` class. + + """ # noqa: E501 + + return self._proxied.new + + @property + def identity_map(self) -> identity.IdentityMap: + r"""Proxy for the :attr:`_orm.Session.identity_map` attribute + on behalf of the :class:`_orm.scoping.scoped_session` class. + + """ # noqa: E501 + + return self._proxied.identity_map + + @identity_map.setter + def identity_map(self, attr: identity.IdentityMap) -> None: + self._proxied.identity_map = attr + + @property + def is_active(self) -> Any: + r"""True if this :class:`.Session` not in "partial rollback" state. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_orm.scoping.scoped_session` class. + + .. versionchanged:: 1.4 The :class:`_orm.Session` no longer begins + a new transaction immediately, so this attribute will be False + when the :class:`_orm.Session` is first instantiated. + + "partial rollback" state typically indicates that the flush process + of the :class:`_orm.Session` has failed, and that the + :meth:`_orm.Session.rollback` method must be emitted in order to + fully roll back the transaction. + + If this :class:`_orm.Session` is not in a transaction at all, the + :class:`_orm.Session` will autobegin when it is first used, so in this + case :attr:`_orm.Session.is_active` will return True. + + Otherwise, if this :class:`_orm.Session` is within a transaction, + and that transaction has not been rolled back internally, the + :attr:`_orm.Session.is_active` will also return True. + + .. seealso:: + + :ref:`faq_session_rollback` + + :meth:`_orm.Session.in_transaction` + + + """ # noqa: E501 + + return self._proxied.is_active + + @property + def autoflush(self) -> bool: + r"""Proxy for the :attr:`_orm.Session.autoflush` attribute + on behalf of the :class:`_orm.scoping.scoped_session` class. + + """ # noqa: E501 + + return self._proxied.autoflush + + @autoflush.setter + def autoflush(self, attr: bool) -> None: + self._proxied.autoflush = attr + + @property + def no_autoflush(self) -> Any: + r"""Return a context manager that disables autoflush. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_orm.scoping.scoped_session` class. + + e.g.:: + + with session.no_autoflush: + + some_object = SomeClass() + session.add(some_object) + # won't autoflush + some_object.related_thing = session.query(SomeRelated).first() + + Operations that proceed within the ``with:`` block + will not be subject to flushes occurring upon query + access. This is useful when initializing a series + of objects which involve existing database queries, + where the uncompleted object should not yet be flushed. + + + """ # noqa: E501 + + return self._proxied.no_autoflush + + @property + def info(self) -> Any: + r"""A user-modifiable dictionary. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class + on behalf of the :class:`_orm.scoping.scoped_session` class. + + The initial value of this dictionary can be populated using the + ``info`` argument to the :class:`.Session` constructor or + :class:`.sessionmaker` constructor or factory methods. The dictionary + here is always local to this :class:`.Session` and can be modified + independently of all other :class:`.Session` objects. + + + """ # noqa: E501 + + return self._proxied.info + + @property + def autocommit(self) -> Any: + r"""Proxy for the :attr:`_orm.Session.autocommit` attribute + on behalf of the :class:`_orm.scoping.scoped_session` class. + + """ # noqa: E501 + + return self._proxied.autocommit + + @autocommit.setter + def autocommit(self, attr: Any) -> None: + self._proxied.autocommit = attr + + @classmethod + def close_all(cls) -> None: + r"""Close *all* sessions in memory. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + .. deprecated:: 1.3 The :meth:`.Session.close_all` method is deprecated and will be removed in a future release. Please refer to :func:`.session.close_all_sessions`. + + """ # noqa: E501 + + return Session.close_all() + + @classmethod + def object_session(cls, instance: Any) -> "Session": + r"""Return the :class:`.Session` to which an object belongs. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + This is an alias of :func:`.object_session`. + + + """ # noqa: E501 + + return Session.object_session(instance) + + @classmethod + def identity_key( + cls, + class_=None, + ident=None, + *, + instance=None, + row=None, + identity_token=None, + ) -> _IdentityKeyType: + r"""Return an identity key. + + .. container:: class_bases + + Proxied for the :class:`_orm.Session` class on + behalf of the :class:`_orm.scoping.scoped_session` class. + + This is an alias of :func:`.util.identity_key`. + + + """ # noqa: E501 + + return Session.identity_key( + class_=class_, + ident=ident, + instance=instance, + row=row, + identity_token=identity_token, + ) + + # END PROXY METHODS scoped_session + ScopedSession = scoped_session """Old name for backwards compatibility.""" diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py index 6279c17fb..77a97936b 100644 --- a/lib/sqlalchemy/orm/session.py +++ b/lib/sqlalchemy/orm/session.py @@ -56,7 +56,6 @@ from ..sql import coercions from ..sql import dml from ..sql import roles from ..sql import visitors -from ..sql._typing import _ColumnsClauseArgument from ..sql.base import CompileState from ..sql.selectable import LABEL_STYLE_TABLENAME_PLUS_COL from ..util.typing import Literal @@ -64,6 +63,7 @@ from ..util.typing import Literal if typing.TYPE_CHECKING: from .mapper import Mapper from ..engine import Row + from ..sql._typing import _ColumnsClauseArgument from ..sql._typing import _ExecuteOptions from ..sql._typing import _ExecuteParams from ..sql.base import Executable @@ -2043,9 +2043,7 @@ class Session(_SessionClassMethods): % (", ".join(context),), ) - def query( - self, *entities: "_ColumnsClauseArgument", **kwargs: Any - ) -> "Query": + def query(self, *entities: _ColumnsClauseArgument, **kwargs: Any) -> Query: """Return a new :class:`_query.Query` object corresponding to this :class:`_orm.Session`. diff --git a/lib/sqlalchemy/testing/plugin/plugin_base.py b/lib/sqlalchemy/testing/plugin/plugin_base.py index 52e42bb97..b90858512 100644 --- a/lib/sqlalchemy/testing/plugin/plugin_base.py +++ b/lib/sqlalchemy/testing/plugin/plugin_base.py @@ -5,14 +5,8 @@ # This module is part of SQLAlchemy and is released under # the MIT License: https://www.opensource.org/licenses/mit-license.php -"""Testing extensions. - -this module is designed to work as a testing-framework-agnostic library, -created so that multiple test frameworks can be supported at once -(mostly so that we can migrate to new ones). The current target -is pytest. +from __future__ import annotations -""" import abc import configparser import logging @@ -23,6 +17,15 @@ from typing import Any from sqlalchemy.testing import asyncio +"""Testing extensions. + +this module is designed to work as a testing-framework-agnostic library, +created so that multiple test frameworks can be supported at once +(mostly so that we can migrate to new ones). The current target +is pytest. + +""" + # flag which indicates we are in the SQLAlchemy testing suite, # and not that of Alembic or a third party dialect. bootstrapped_as_sqlalchemy = False diff --git a/lib/sqlalchemy/testing/plugin/pytestplugin.py b/lib/sqlalchemy/testing/plugin/pytestplugin.py index 6efeac504..ab93e60e2 100644 --- a/lib/sqlalchemy/testing/plugin/pytestplugin.py +++ b/lib/sqlalchemy/testing/plugin/pytestplugin.py @@ -1,9 +1,4 @@ -try: - # installed by bootstrap.py - import sqla_plugin_base as plugin_base -except ImportError: - # assume we're a package, use traditional import - from . import plugin_base +from __future__ import annotations import argparse import collections @@ -17,6 +12,13 @@ import uuid import pytest +try: + # installed by bootstrap.py + import sqla_plugin_base as plugin_base +except ImportError: + # assume we're a package, use traditional import + from . import plugin_base + def pytest_addoption(parser): group = parser.getgroup("sqlalchemy") @@ -565,6 +567,10 @@ def _pytest_fn_decorator(target): from sqlalchemy.util.compat import inspect_getfullargspec def _exec_code_in_env(code, env, fn_name): + # note this is affected by "from __future__ import annotations" at + # the top; exec'ed code will use non-evaluated annotations + # which allows us to be more flexible with code rendering + # in format_argpsec_plus() exec(code, env) return env[fn_name] diff --git a/lib/sqlalchemy/util/compat.py b/lib/sqlalchemy/util/compat.py index d30236dd9..aeaefa40e 100644 --- a/lib/sqlalchemy/util/compat.py +++ b/lib/sqlalchemy/util/compat.py @@ -139,17 +139,17 @@ def _formatannotation(annotation, base_module=None): """vendored from python 3.7""" if isinstance(annotation, str): - return f'"{annotation}"' + return annotation if getattr(annotation, "__module__", None) == "typing": - return f'"{repr(annotation).replace("typing.", "").replace("~", "")}"' + return repr(annotation).replace("typing.", "").replace("~", "") if isinstance(annotation, type): if annotation.__module__ in ("builtins", base_module): return repr(annotation.__qualname__) return annotation.__module__ + "." + annotation.__qualname__ elif isinstance(annotation, typing.TypeVar): - return f'"{repr(annotation).replace("~", "")}"' - return f'"{repr(annotation).replace("~", "")}"' + return repr(annotation).replace("~", "") + return repr(annotation).replace("~", "") def inspect_formatargspec( diff --git a/lib/sqlalchemy/util/langhelpers.py b/lib/sqlalchemy/util/langhelpers.py index 8f0ec700f..3e89c72bb 100644 --- a/lib/sqlalchemy/util/langhelpers.py +++ b/lib/sqlalchemy/util/langhelpers.py @@ -678,111 +678,17 @@ def create_proxy_methods( methods=(), attributes=(), ): - """A class decorator that will copy attributes to a proxy class. + """A class decorator indicating attributes should refer to a proxy + class. - The class to be instrumented must define a single accessor "_proxied". + This decorator is now a "marker" that does nothing at runtime. Instead, + it is consumed by the tools/generate_proxy_methods.py script to + statically generate proxy methods and attributes that are fully + recognized by typing tools such as mypy. """ def decorate(cls): - def instrument(name, clslevel=False): - fn = cast(types.FunctionType, getattr(target_cls, name)) - spec = compat.inspect_getfullargspec(fn) - env = {"__name__": fn.__module__} - - spec = _update_argspec_defaults_into_env(spec, env) - caller_argspec = format_argspec_plus(spec, grouped=False) - - metadata = { - "name": fn.__name__, - "apply_pos_proxied": caller_argspec["apply_pos_proxied"], - "apply_kw_proxied": caller_argspec["apply_kw_proxied"], - "grouped_args": caller_argspec["grouped_args"], - "self_arg": caller_argspec["self_arg"], - } - - if clslevel: - code = ( - "def %(name)s%(grouped_args)s:\n" - " return target_cls.%(name)s(%(apply_kw_proxied)s)" - % metadata - ) - env["target_cls"] = target_cls - else: - code = ( - "def %(name)s%(grouped_args)s:\n" - " return %(self_arg)s._proxied.%(name)s(%(apply_kw_proxied)s)" # noqa: E501 - % metadata - ) - - proxy_fn = cast( - types.FunctionType, _exec_code_in_env(code, env, fn.__name__) - ) - proxy_fn.__defaults__ = getattr(fn, "__func__", fn).__defaults__ - proxy_fn.__doc__ = inject_docstring_text( - fn.__doc__, - ".. container:: class_bases\n\n " - "Proxied for the %s class on behalf of the %s class." - % (target_cls_sphinx_name, proxy_cls_sphinx_name), - 1, - ) - - if clslevel: - return classmethod(proxy_fn) - else: - return proxy_fn - - def makeprop(name): - attr = target_cls.__dict__.get(name, None) - - if attr is not None: - doc = inject_docstring_text( - attr.__doc__, - ".. container:: class_bases\n\n " - "Proxied for the %s class on behalf of the %s class." - % ( - target_cls_sphinx_name, - proxy_cls_sphinx_name, - ), - 1, - ) - else: - doc = None - - code = ( - "def set_(self, attr):\n" - " self._proxied.%(name)s = attr\n" - "def get(self):\n" - " return self._proxied.%(name)s\n" - "get.__doc__ = doc\n" - "getset = property(get, set_)" - ) % {"name": name} - - getset = _exec_code_in_env(code, {"doc": doc}, "getset") - - return getset - - for meth in methods: - if hasattr(cls, meth): - raise TypeError( - "class %s already has a method %s" % (cls, meth) - ) - setattr(cls, meth, instrument(meth)) - - for prop in attributes: - if hasattr(cls, prop): - raise TypeError( - "class %s already has a method %s" % (cls, prop) - ) - setattr(cls, prop, makeprop(prop)) - - for prop in classmethods: - if hasattr(cls, prop): - raise TypeError( - "class %s already has a method %s" % (cls, prop) - ) - setattr(cls, prop, instrument(prop, clslevel=True)) - return cls return decorate diff --git a/test/ext/asyncio/test_scoping_py3k.py b/test/ext/asyncio/test_scoping_py3k.py index d722320f3..caba1c660 100644 --- a/test/ext/asyncio/test_scoping_py3k.py +++ b/test/ext/asyncio/test_scoping_py3k.py @@ -37,8 +37,9 @@ class AsyncScopedSessionTest(AsyncFixture): await AsyncSession.flush() conn = await AsyncSession.connection() + stmt = select(func.count(User.id)).where(User.name == user_name) - eq_(await conn.scalar(stmt), 1) + eq_(await AsyncSession.scalar(stmt), 1) await AsyncSession.delete(u1) await AsyncSession.flush() diff --git a/tools/generate_proxy_methods.py b/tools/generate_proxy_methods.py new file mode 100644 index 000000000..eec4d878a --- /dev/null +++ b/tools/generate_proxy_methods.py @@ -0,0 +1,413 @@ +"""Generate static proxy code for SQLAlchemy classes that proxy other +objects. + +This tool is run at source code authoring / commit time whenever we add new +methods to engines/connections/sessions that need to be generically proxied by +scoped_session or asyncio. The generated code is part of what's committed +to source just as though we typed it all by hand. + +The original "proxy" class was scoped_session. Then with asyncio, all the +asyncio objects are essentially "proxy" objects as well; while all the methods +that are "async" needed to be written by hand, there's lots of other attributes +and methods that are proxied exactly. + +To eliminate redundancy, all of these classes made use of the +@langhelpers.create_proxy_methods() decorator which at runtime would read a +selected list of methods and attributes from the proxied class and generate new +methods and properties descriptors on the proxying class; this way the proxy +would have all the same methods signatures / attributes / docstrings consumed +by Sphinx and look just like the proxied class. + +Then mypy and typing came along, which don't care about runtime generated code +and never will. So this script takes that same +@langhelpers.create_proxy_methods() decorator, keeps its public interface just +as is, and uses it to generate all the code and docs in those proxy classes +statically, as though we sat there and spent seven hours typing it all by hand. +The runtime code generation part is removed from ``create_proxy_methods()``. +Now we have static code that is perfectly consumable by all the typing tools +and we also reduce import time a bit. + +A similar approach is used in Alembic where a dynamic approach towards creating +alembic "ops" was enhanced to generate a .pyi stubs file statically for +consumption by typing tools. + +.. versionadded:: 2.0 + +""" +from __future__ import annotations + +from argparse import ArgumentParser +import collections +import importlib +import inspect +import os +from pathlib import Path +import re +import shlex +import shutil +import subprocess +import sys +from tempfile import NamedTemporaryFile +import textwrap +from typing import Any +from typing import Callable +from typing import Dict +from typing import Iterable +from typing import TextIO +from typing import Tuple +from typing import Type +from typing import TypeVar + +from sqlalchemy import util +from sqlalchemy.util import compat +from sqlalchemy.util import langhelpers +from sqlalchemy.util.langhelpers import format_argspec_plus +from sqlalchemy.util.langhelpers import inject_docstring_text + +is_posix = os.name == "posix" + + +sys.path.append(str(Path(__file__).parent.parent)) + + +class _repr_sym: + __slots__ = ("sym",) + + def __init__(self, sym: str): + self.sym = sym + + def __repr__(self) -> str: + return self.sym + + +classes: collections.defaultdict[ + str, Dict[str, Tuple[Any, ...]] +] = collections.defaultdict(dict) + +_T = TypeVar("_T", bound="Any") + + +def create_proxy_methods( + target_cls: Type[Any], + target_cls_sphinx_name: str, + proxy_cls_sphinx_name: str, + classmethods: Iterable[str] = (), + methods: Iterable[str] = (), + attributes: Iterable[str] = (), +) -> Callable[[Type[_T]], Type[_T]]: + """A class decorator that will copy attributes to a proxy class. + + The class to be instrumented must define a single accessor "_proxied". + + """ + + def decorate(cls: Type[_T]) -> Type[_T]: + # collect the class as a separate step. since the decorator + # is called as a result of imports, the order in which classes + # are collected (like in asyncio) can't be well controlled. however, + # the proxies (specifically asyncio session and asyncio scoped_session) + # have to be generated in dependency order, so run them in order in a + # second step. + classes[cls.__module__][cls.__name__] = ( + target_cls, + target_cls_sphinx_name, + proxy_cls_sphinx_name, + classmethods, + methods, + attributes, + cls, + ) + return cls + + return decorate + + +def process_class( + buf: TextIO, + target_cls: Type[Any], + target_cls_sphinx_name: str, + proxy_cls_sphinx_name: str, + classmethods: Iterable[str], + methods: Iterable[str], + attributes: Iterable[str], + cls: Type[Any], +): + + sphinx_symbol_match = re.match(r":class:`(.+)`", target_cls_sphinx_name) + if not sphinx_symbol_match: + raise Exception( + f"Couldn't match sphinx class identifier from " + f"target_cls_sphinx_name f{target_cls_sphinx_name!r}. Currently " + 'this program expects the form ":class:`_<prefix>.<clsname>`"' + ) + + sphinx_symbol = sphinx_symbol_match.group(1) + + def instrument(buf: TextIO, name: str, clslevel: bool = False) -> None: + fn = getattr(target_cls, name) + spec = compat.inspect_getfullargspec(fn) + + iscoroutine = inspect.iscoroutinefunction(fn) + + if spec.defaults: + new_defaults = tuple( + _repr_sym("util.EMPTY_DICT") if df is util.EMPTY_DICT else df + for df in spec.defaults + ) + elem = list(spec) + elem[3] = tuple(new_defaults) + spec = compat.FullArgSpec(*elem) + + caller_argspec = format_argspec_plus(spec, grouped=False) + + metadata = { + "name": fn.__name__, + "async": "async " if iscoroutine else "", + "await": "await " if iscoroutine else "", + "apply_pos_proxied": caller_argspec["apply_pos_proxied"], + "target_cls_name": target_cls.__name__, + "apply_kw_proxied": caller_argspec["apply_kw_proxied"], + "grouped_args": caller_argspec["grouped_args"], + "self_arg": caller_argspec["self_arg"], + "doc": textwrap.indent( + inject_docstring_text( + fn.__doc__, + textwrap.indent( + ".. container:: class_bases\n\n" + f" Proxied for the {target_cls_sphinx_name} " + "class on \n" + f" behalf of the {proxy_cls_sphinx_name} " + "class.", + " ", + ), + 1, + ), + " ", + ).lstrip(), + } + + if clslevel: + code = ( + "@classmethod\n" + "%(async)sdef %(name)s%(grouped_args)s:\n" + ' r"""%(doc)s\n """ # noqa: E501\n\n' + " return %(await)s%(target_cls_name)s.%(name)s(%(apply_kw_proxied)s)\n\n" # noqa: E501 + % metadata + ) + else: + code = ( + "%(async)sdef %(name)s%(grouped_args)s:\n" + ' r"""%(doc)s\n """ # noqa: E501\n\n' + " return %(await)s%(self_arg)s._proxied.%(name)s(%(apply_kw_proxied)s)\n\n" # noqa: E501 + % metadata + ) + + buf.write(textwrap.indent(code, " ")) + + def makeprop(buf: TextIO, name: str) -> None: + attr = target_cls.__dict__.get(name, None) + + return_type = target_cls.__annotations__.get(name, "Any") + assert isinstance(return_type, str), ( + "expected string annotations, is from __future__ " + "import annotations set up?" + ) + + if attr is not None: + if isinstance(attr, property): + readonly = attr.fset is None + elif isinstance(attr, langhelpers.generic_fn_descriptor): + readonly = True + else: + readonly = not hasattr(attr, "__set__") + doc = textwrap.indent( + inject_docstring_text( + attr.__doc__, + textwrap.indent( + ".. container:: class_bases\n\n" + f" Proxied for the {target_cls_sphinx_name} " + "class \n" + f" on behalf of the {proxy_cls_sphinx_name} " + "class.", + " ", + ), + 1, + ), + " ", + ).lstrip() + else: + readonly = False + doc = ( + f"Proxy for the :attr:`{sphinx_symbol}.{name}` " + "attribute \n" + f" on behalf of the {proxy_cls_sphinx_name} " + "class.\n" + ) + + code = ( + "@property\n" + "def %(name)s(self) -> %(return_type)s:\n" + ' r"""%(doc)s\n """ # noqa: E501\n\n' + " return self._proxied.%(name)s\n\n" + ) % {"name": name, "doc": doc, "return_type": return_type} + + if not readonly: + code += ( + "@%(name)s.setter\n" + "def %(name)s(self, attr: %(return_type)s) -> None:\n" + " self._proxied.%(name)s = attr\n\n" + ) % {"name": name, "doc": doc, "return_type": return_type} + + buf.write(textwrap.indent(code, " ")) + + for meth in methods: + instrument(buf, meth) + + for prop in attributes: + makeprop(buf, prop) + + for prop in classmethods: + instrument(buf, prop, clslevel=True) + + +def process_module(modname: str, filename: str) -> str: + + class_entries = classes[modname] + + # use tempfile in same path as the module, or at least in the + # current working directory, so that black / zimports use + # local pyproject.toml + with NamedTemporaryFile( + mode="w", delete=False, suffix=".py", dir=Path(filename).parent + ) as buf, open(filename) as orig_py: + + in_block = False + current_clsname = None + for line in orig_py: + m = re.match(r" # START PROXY METHODS (.+)$", line) + if m: + current_clsname = m.group(1) + args = class_entries[current_clsname] + sys.stderr.write( + f"Generating attributes for class {current_clsname}\n" + ) + in_block = True + buf.write(line) + buf.write( + "\n # code within this block is " + "**programmatically, \n" + " # statically generated** by" + " tools/generate_proxy_methods.py\n\n" + ) + + process_class(buf, *args) + if line.startswith(f" # END PROXY METHODS {current_clsname}"): + in_block = False + + if not in_block: + buf.write(line) + return buf.name + + +def console_scripts( + path: str, options: dict, ignore_output: bool = False +) -> None: + + entrypoint_name = options["entrypoint"] + + for entry in compat.importlib_metadata_get("console_scripts"): + if entry.name == entrypoint_name: + impl = entry + break + else: + raise Exception( + f"Could not find entrypoint console_scripts.{entrypoint_name}" + ) + cmdline_options_str = options.get("options", "") + cmdline_options_list = shlex.split(cmdline_options_str, posix=is_posix) + [ + path + ] + + kw = {} + if ignore_output: + kw["stdout"] = kw["stderr"] = subprocess.DEVNULL + + subprocess.run( + [ + sys.executable, + "-c", + "import %s; %s.%s()" % (impl.module, impl.module, impl.attr), + ] + + cmdline_options_list, + cwd=Path(__file__).parent.parent, + **kw, + ) + + +def run_module(modname, stdout): + + sys.stderr.write(f"importing module {modname}\n") + mod = importlib.import_module(modname) + filename = destination_path = mod.__file__ + assert filename is not None + + tempfile = process_module(modname, filename) + + ignore_output = stdout + + console_scripts( + str(tempfile), + {"entrypoint": "zimports"}, + ignore_output=ignore_output, + ) + + console_scripts( + str(tempfile), + {"entrypoint": "black"}, + ignore_output=ignore_output, + ) + + if stdout: + with open(tempfile) as tf: + print(tf.read()) + os.unlink(tempfile) + else: + sys.stderr.write(f"Writing {destination_path}...\n") + shutil.move(tempfile, destination_path) + + +def main(args): + from sqlalchemy import util + from sqlalchemy.util import langhelpers + + util.create_proxy_methods = ( + langhelpers.create_proxy_methods + ) = create_proxy_methods + + for entry in entries: + if args.module in {"all", entry}: + run_module(entry, args.stdout) + + +entries = [ + "sqlalchemy.orm.scoping", + "sqlalchemy.ext.asyncio.engine", + "sqlalchemy.ext.asyncio.session", + "sqlalchemy.ext.asyncio.scoping", +] + +if __name__ == "__main__": + parser = ArgumentParser() + parser.add_argument( + "--module", + choices=entries + ["all"], + default="all", + help="Which file to generate. Default is to regenerate all files", + ) + parser.add_argument( + "--stdout", + action="store_true", + help="Write to stdout instead of saving to file", + ) + args = parser.parse_args() + main(args) |