# dialects/postgresql/psycopg.py # Copyright (C) 2005-2024 the SQLAlchemy authors and contributors # # # This module is part of SQLAlchemy and is released under # the MIT License: https://www.opensource.org/licenses/mit-license.php # mypy: ignore-errors r""" .. dialect:: postgresql+psycopg :name: psycopg (a.k.a. psycopg 3) :dbapi: psycopg :connectstring: postgresql+psycopg://user:password@host:port/dbname[?key=value&key=value...] :url: https://pypi.org/project/psycopg/ ``psycopg`` is the package and module name for version 3 of the ``psycopg`` database driver, formerly known as ``psycopg2``. This driver is different enough from its ``psycopg2`` predecessor that SQLAlchemy supports it via a totally separate dialect; support for ``psycopg2`` is expected to remain for as long as that package continues to function for modern Python versions, and also remains the default dialect for the ``postgresql://`` dialect series. The SQLAlchemy ``psycopg`` dialect provides both a sync and an async implementation under the same dialect name. The proper version is selected depending on how the engine is created: * calling :func:`_sa.create_engine` with ``postgresql+psycopg://...`` will automatically select the sync version, e.g.:: from sqlalchemy import create_engine sync_engine = create_engine("postgresql+psycopg://scott:tiger@localhost/test") * calling :func:`_asyncio.create_async_engine` with ``postgresql+psycopg://...`` will automatically select the async version, e.g.:: from sqlalchemy.ext.asyncio import create_async_engine asyncio_engine = create_async_engine("postgresql+psycopg://scott:tiger@localhost/test") The asyncio version of the dialect may also be specified explicitly using the ``psycopg_async`` suffix, as:: from sqlalchemy.ext.asyncio import create_async_engine asyncio_engine = create_async_engine("postgresql+psycopg_async://scott:tiger@localhost/test") .. seealso:: :ref:`postgresql_psycopg2` - The SQLAlchemy ``psycopg`` dialect shares most of its behavior with the ``psycopg2`` dialect. Further documentation is available there. Using a different Cursor class ------------------------------ One of the differences between ``psycopg`` and the older ``psycopg2`` is how bound parameters are handled: ``psycopg2`` would bind them client side, while ``psycopg`` by default will bind them server side. It's possible to configure ``psycopg`` to do client side binding by specifying the ``cursor_factory`` to be ``ClientCursor`` when creating the engine:: from psycopg import ClientCursor client_side_engine = create_engine( "postgresql+psycopg://...", connect_args={"cursor_factory": ClientCursor}, ) Similarly when using an async engine the ``AsyncClientCursor`` can be specified:: from psycopg import AsyncClientCursor client_side_engine = create_async_engine( "postgresql+psycopg://...", connect_args={"cursor_factory": AsyncClientCursor}, ) .. seealso:: `Client-side-binding cursors `_ """ # noqa from __future__ import annotations from collections import deque import logging import re from typing import cast from typing import TYPE_CHECKING from . import ranges from ._psycopg_common import _PGDialect_common_psycopg from ._psycopg_common import _PGExecutionContext_common_psycopg from .base import INTERVAL from .base import PGCompiler from .base import PGIdentifierPreparer from .base import REGCONFIG from .json import JSON from .json import JSONB from .json import JSONPathType from .types import CITEXT from ... import pool from ... import util from ...engine import AdaptedConnection from ...sql import sqltypes from ...util.concurrency import await_fallback from ...util.concurrency import await_only if TYPE_CHECKING: from typing import Iterable from psycopg import AsyncConnection logger = logging.getLogger("sqlalchemy.dialects.postgresql") class _PGString(sqltypes.String): render_bind_cast = True class _PGREGCONFIG(REGCONFIG): render_bind_cast = True class _PGJSON(JSON): render_bind_cast = True def bind_processor(self, dialect): return self._make_bind_processor(None, dialect._psycopg_Json) def result_processor(self, dialect, coltype): return None class _PGJSONB(JSONB): render_bind_cast = True def bind_processor(self, dialect): return self._make_bind_processor(None, dialect._psycopg_Jsonb) def result_processor(self, dialect, coltype): return None class _PGJSONIntIndexType(sqltypes.JSON.JSONIntIndexType): __visit_name__ = "json_int_index" render_bind_cast = True class _PGJSONStrIndexType(sqltypes.JSON.JSONStrIndexType): __visit_name__ = "json_str_index" render_bind_cast = True class _PGJSONPathType(JSONPathType): pass class _PGInterval(INTERVAL): render_bind_cast = True class _PGTimeStamp(sqltypes.DateTime): render_bind_cast = True class _PGDate(sqltypes.Date): render_bind_cast = True class _PGTime(sqltypes.Time): render_bind_cast = True class _PGInteger(sqltypes.Integer): render_bind_cast = True class _PGSmallInteger(sqltypes.SmallInteger): render_bind_cast = True class _PGNullType(sqltypes.NullType): render_bind_cast = True class _PGBigInteger(sqltypes.BigInteger): render_bind_cast = True class _PGBoolean(sqltypes.Boolean): render_bind_cast = True class _PsycopgRange(ranges.AbstractSingleRangeImpl): def bind_processor(self, dialect): psycopg_Range = cast(PGDialect_psycopg, dialect)._psycopg_Range def to_range(value): if isinstance(value, ranges.Range): value = psycopg_Range( value.lower, value.upper, value.bounds, value.empty ) return value return to_range def result_processor(self, dialect, coltype): def to_range(value): if value is not None: value = ranges.Range( value._lower, value._upper, bounds=value._bounds if value._bounds else "[)", empty=not value._bounds, ) return value return to_range class _PsycopgMultiRange(ranges.AbstractMultiRangeImpl): def bind_processor(self, dialect): psycopg_Range = cast(PGDialect_psycopg, dialect)._psycopg_Range psycopg_Multirange = cast( PGDialect_psycopg, dialect )._psycopg_Multirange NoneType = type(None) def to_range(value): if isinstance(value, (str, NoneType, psycopg_Multirange)): return value return psycopg_Multirange( [ psycopg_Range( element.lower, element.upper, element.bounds, element.empty, ) for element in cast("Iterable[ranges.Range]", value) ] ) return to_range def result_processor(self, dialect, coltype): def to_range(value): if value is None: return None else: return ranges.MultiRange( ranges.Range( elem._lower, elem._upper, bounds=elem._bounds if elem._bounds else "[)", empty=not elem._bounds, ) for elem in value ) return to_range class PGExecutionContext_psycopg(_PGExecutionContext_common_psycopg): pass class PGCompiler_psycopg(PGCompiler): pass class PGIdentifierPreparer_psycopg(PGIdentifierPreparer): pass def _log_notices(diagnostic): logger.info("%s: %s", diagnostic.severity, diagnostic.message_primary) class PGDialect_psycopg(_PGDialect_common_psycopg): driver = "psycopg" supports_statement_cache = True supports_server_side_cursors = True default_paramstyle = "pyformat" supports_sane_multi_rowcount = True execution_ctx_cls = PGExecutionContext_psycopg statement_compiler = PGCompiler_psycopg preparer = PGIdentifierPreparer_psycopg psycopg_version = (0, 0) _has_native_hstore = True _psycopg_adapters_map = None colspecs = util.update_copy( _PGDialect_common_psycopg.colspecs, { sqltypes.String: _PGString, REGCONFIG: _PGREGCONFIG, JSON: _PGJSON, CITEXT: CITEXT, sqltypes.JSON: _PGJSON, JSONB: _PGJSONB, sqltypes.JSON.JSONPathType: _PGJSONPathType, sqltypes.JSON.JSONIntIndexType: _PGJSONIntIndexType, sqltypes.JSON.JSONStrIndexType: _PGJSONStrIndexType, sqltypes.Interval: _PGInterval, INTERVAL: _PGInterval, sqltypes.Date: _PGDate, sqltypes.DateTime: _PGTimeStamp, sqltypes.Time: _PGTime, sqltypes.Integer: _PGInteger, sqltypes.SmallInteger: _PGSmallInteger, sqltypes.BigInteger: _PGBigInteger, ranges.AbstractSingleRange: _PsycopgRange, ranges.AbstractMultiRange: _PsycopgMultiRange, }, ) def __init__(self, **kwargs): super().__init__(**kwargs) if self.dbapi: m = re.match(r"(\d+)\.(\d+)(?:\.(\d+))?", self.dbapi.__version__) if m: self.psycopg_version = tuple( int(x) for x in m.group(1, 2, 3) if x is not None ) if self.psycopg_version < (3, 0, 2): raise ImportError( "psycopg version 3.0.2 or higher is required." ) from psycopg.adapt import AdaptersMap self._psycopg_adapters_map = adapters_map = AdaptersMap( self.dbapi.adapters ) if self._native_inet_types is False: import psycopg.types.string adapters_map.register_loader( "inet", psycopg.types.string.TextLoader ) adapters_map.register_loader( "cidr", psycopg.types.string.TextLoader ) if self._json_deserializer: from psycopg.types.json import set_json_loads set_json_loads(self._json_deserializer, adapters_map) if self._json_serializer: from psycopg.types.json import set_json_dumps set_json_dumps(self._json_serializer, adapters_map) def create_connect_args(self, url): # see https://github.com/psycopg/psycopg/issues/83 cargs, cparams = super().create_connect_args(url) if self._psycopg_adapters_map: cparams["context"] = self._psycopg_adapters_map if self.client_encoding is not None: cparams["client_encoding"] = self.client_encoding return cargs, cparams def _type_info_fetch(self, connection, name): from psycopg.types import TypeInfo return TypeInfo.fetch(connection.connection.driver_connection, name) def initialize(self, connection): super().initialize(connection) # PGDialect.initialize() checks server version for <= 8.2 and sets # this flag to False if so if not self.insert_returning: self.insert_executemany_returning = False # HSTORE can't be registered until we have a connection so that # we can look up its OID, so we set up this adapter in # initialize() if self.use_native_hstore: info = self._type_info_fetch(connection, "hstore") self._has_native_hstore = info is not None if self._has_native_hstore: from psycopg.types.hstore import register_hstore # register the adapter for connections made subsequent to # this one register_hstore(info, self._psycopg_adapters_map) # register the adapter for this connection register_hstore(info, connection.connection) @classmethod def import_dbapi(cls): import psycopg return psycopg @classmethod def get_async_dialect_cls(cls, url): return PGDialectAsync_psycopg @util.memoized_property def _isolation_lookup(self): return { "READ COMMITTED": self.dbapi.IsolationLevel.READ_COMMITTED, "READ UNCOMMITTED": self.dbapi.IsolationLevel.READ_UNCOMMITTED, "REPEATABLE READ": self.dbapi.IsolationLevel.REPEATABLE_READ, "SERIALIZABLE": self.dbapi.IsolationLevel.SERIALIZABLE, } @util.memoized_property def _psycopg_Json(self): from psycopg.types import json return json.Json @util.memoized_property def _psycopg_Jsonb(self): from psycopg.types import json return json.Jsonb @util.memoized_property def _psycopg_TransactionStatus(self): from psycopg.pq import TransactionStatus return TransactionStatus @util.memoized_property def _psycopg_Range(self): from psycopg.types.range import Range return Range @util.memoized_property def _psycopg_Multirange(self): from psycopg.types.multirange import Multirange return Multirange def _do_isolation_level(self, connection, autocommit, isolation_level): connection.autocommit = autocommit connection.isolation_level = isolation_level def get_isolation_level(self, dbapi_connection): status_before = dbapi_connection.info.transaction_status value = super().get_isolation_level(dbapi_connection) # don't rely on psycopg providing enum symbols, compare with # eq/ne if status_before == self._psycopg_TransactionStatus.IDLE: dbapi_connection.rollback() return value def set_isolation_level(self, dbapi_connection, level): if level == "AUTOCOMMIT": self._do_isolation_level( dbapi_connection, autocommit=True, isolation_level=None ) else: self._do_isolation_level( dbapi_connection, autocommit=False, isolation_level=self._isolation_lookup[level], ) def set_readonly(self, connection, value): connection.read_only = value def get_readonly(self, connection): return connection.read_only def on_connect(self): def notices(conn): conn.add_notice_handler(_log_notices) fns = [notices] if self.isolation_level is not None: def on_connect(conn): self.set_isolation_level(conn, self.isolation_level) fns.append(on_connect) # fns always has the notices function def on_connect(conn): for fn in fns: fn(conn) return on_connect def is_disconnect(self, e, connection, cursor): if isinstance(e, self.dbapi.Error) and connection is not None: if connection.closed or connection.broken: return True return False def _do_prepared_twophase(self, connection, command, recover=False): dbapi_conn = connection.connection.dbapi_connection if ( recover # don't rely on psycopg providing enum symbols, compare with # eq/ne or dbapi_conn.info.transaction_status != self._psycopg_TransactionStatus.IDLE ): dbapi_conn.rollback() before_autocommit = dbapi_conn.autocommit try: if not before_autocommit: self._do_autocommit(dbapi_conn, True) dbapi_conn.execute(command) finally: if not before_autocommit: self._do_autocommit(dbapi_conn, before_autocommit) def do_rollback_twophase( self, connection, xid, is_prepared=True, recover=False ): if is_prepared: self._do_prepared_twophase( connection, f"ROLLBACK PREPARED '{xid}'", recover=recover ) else: self.do_rollback(connection.connection) def do_commit_twophase( self, connection, xid, is_prepared=True, recover=False ): if is_prepared: self._do_prepared_twophase( connection, f"COMMIT PREPARED '{xid}'", recover=recover ) else: self.do_commit(connection.connection) @util.memoized_property def _dialect_specific_select_one(self): return ";" class AsyncAdapt_psycopg_cursor: __slots__ = ("_cursor", "await_", "_rows") _psycopg_ExecStatus = None def __init__(self, cursor, await_) -> None: self._cursor = cursor self.await_ = await_ self._rows = deque() def __getattr__(self, name): return getattr(self._cursor, name) @property def arraysize(self): return self._cursor.arraysize @arraysize.setter def arraysize(self, value): self._cursor.arraysize = value def close(self): self._rows.clear() # Normal cursor just call _close() in a non-sync way. self._cursor._close() def execute(self, query, params=None, **kw): result = self.await_(self._cursor.execute(query, params, **kw)) # sqlalchemy result is not async, so need to pull all rows here res = self._cursor.pgresult # don't rely on psycopg providing enum symbols, compare with # eq/ne if res and res.status == self._psycopg_ExecStatus.TUPLES_OK: rows = self.await_(self._cursor.fetchall()) self._rows = deque(rows) return result def executemany(self, query, params_seq): return self.await_(self._cursor.executemany(query, params_seq)) def __iter__(self): while self._rows: yield self._rows.popleft() def fetchone(self): if self._rows: return self._rows.popleft() else: return None def fetchmany(self, size=None): if size is None: size = self._cursor.arraysize rr = self._rows return [rr.popleft() for _ in range(min(size, len(rr)))] def fetchall(self): retval = list(self._rows) self._rows.clear() return retval class AsyncAdapt_psycopg_ss_cursor(AsyncAdapt_psycopg_cursor): def execute(self, query, params=None, **kw): self.await_(self._cursor.execute(query, params, **kw)) return self def close(self): self.await_(self._cursor.close()) def fetchone(self): return self.await_(self._cursor.fetchone()) def fetchmany(self, size=0): return self.await_(self._cursor.fetchmany(size)) def fetchall(self): return self.await_(self._cursor.fetchall()) def __iter__(self): iterator = self._cursor.__aiter__() while True: try: yield self.await_(iterator.__anext__()) except StopAsyncIteration: break class AsyncAdapt_psycopg_connection(AdaptedConnection): _connection: AsyncConnection __slots__ = () await_ = staticmethod(await_only) def __init__(self, connection) -> None: self._connection = connection def __getattr__(self, name): return getattr(self._connection, name) def execute(self, query, params=None, **kw): cursor = self.await_(self._connection.execute(query, params, **kw)) return AsyncAdapt_psycopg_cursor(cursor, self.await_) def cursor(self, *args, **kw): cursor = self._connection.cursor(*args, **kw) if hasattr(cursor, "name"): return AsyncAdapt_psycopg_ss_cursor(cursor, self.await_) else: return AsyncAdapt_psycopg_cursor(cursor, self.await_) def commit(self): self.await_(self._connection.commit()) def rollback(self): self.await_(self._connection.rollback()) def close(self): self.await_(self._connection.close()) @property def autocommit(self): return self._connection.autocommit @autocommit.setter def autocommit(self, value): self.set_autocommit(value) def set_autocommit(self, value): self.await_(self._connection.set_autocommit(value)) def set_isolation_level(self, value): self.await_(self._connection.set_isolation_level(value)) def set_read_only(self, value): self.await_(self._connection.set_read_only(value)) def set_deferrable(self, value): self.await_(self._connection.set_deferrable(value)) class AsyncAdaptFallback_psycopg_connection(AsyncAdapt_psycopg_connection): __slots__ = () await_ = staticmethod(await_fallback) class PsycopgAdaptDBAPI: def __init__(self, psycopg) -> None: self.psycopg = psycopg for k, v in self.psycopg.__dict__.items(): if k != "connect": self.__dict__[k] = v def connect(self, *arg, **kw): async_fallback = kw.pop("async_fallback", False) creator_fn = kw.pop( "async_creator_fn", self.psycopg.AsyncConnection.connect ) if util.asbool(async_fallback): return AsyncAdaptFallback_psycopg_connection( await_fallback(creator_fn(*arg, **kw)) ) else: return AsyncAdapt_psycopg_connection( await_only(creator_fn(*arg, **kw)) ) class PGDialectAsync_psycopg(PGDialect_psycopg): is_async = True supports_statement_cache = True @classmethod def import_dbapi(cls): import psycopg from psycopg.pq import ExecStatus AsyncAdapt_psycopg_cursor._psycopg_ExecStatus = ExecStatus return PsycopgAdaptDBAPI(psycopg) @classmethod def get_pool_class(cls, url): async_fallback = url.query.get("async_fallback", False) if util.asbool(async_fallback): return pool.FallbackAsyncAdaptedQueuePool else: return pool.AsyncAdaptedQueuePool def _type_info_fetch(self, connection, name): from psycopg.types import TypeInfo adapted = connection.connection return adapted.await_(TypeInfo.fetch(adapted.driver_connection, name)) def _do_isolation_level(self, connection, autocommit, isolation_level): connection.set_autocommit(autocommit) connection.set_isolation_level(isolation_level) def _do_autocommit(self, connection, value): connection.set_autocommit(value) def set_readonly(self, connection, value): connection.set_read_only(value) def set_deferrable(self, connection, value): connection.set_deferrable(value) def get_driver_connection(self, connection): return connection._connection dialect = PGDialect_psycopg dialect_async = PGDialectAsync_psycopg