Current File : //opt/hc_python/lib64/python3.8/site-packages/sqlalchemy/dialects/oracle/oracledb.py
# dialects/oracle/oracledb.py
# Copyright (C) 2005-2024 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# 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:: oracle+oracledb
:name: python-oracledb
:dbapi: oracledb
:connectstring: oracle+oracledb://user:pass@hostname:port[/dbname][?service_name=<service>[&key=value&key=value...]]
:url: https://oracle.github.io/python-oracledb/
Description
-----------
python-oracledb is released by Oracle to supersede the cx_Oracle driver.
It is fully compatible with cx_Oracle and features both a "thin" client
mode that requires no dependencies, as well as a "thick" mode that uses
the Oracle Client Interface in the same way as cx_Oracle.
.. seealso::
:ref:`cx_oracle` - all of cx_Oracle's notes apply to the oracledb driver
as well, with the exception that oracledb supports two phase transactions.
The SQLAlchemy ``oracledb`` 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 ``oracle+oracledb://...`` will
automatically select the sync version, e.g.::
from sqlalchemy import create_engine
sync_engine = create_engine("oracle+oracledb://scott:tiger@localhost/?service_name=XEPDB1")
* calling :func:`_asyncio.create_async_engine` with
``oracle+oracledb://...`` will automatically select the async version,
e.g.::
from sqlalchemy.ext.asyncio import create_async_engine
asyncio_engine = create_async_engine("oracle+oracledb://scott:tiger@localhost/?service_name=XEPDB1")
The asyncio version of the dialect may also be specified explicitly using the
``oracledb_async`` suffix, as::
from sqlalchemy.ext.asyncio import create_async_engine
asyncio_engine = create_async_engine("oracle+oracledb_async://scott:tiger@localhost/?service_name=XEPDB1")
.. versionadded:: 2.0.25 added support for the async version of oracledb.
Thick mode support
------------------
By default the ``python-oracledb`` is started in thin mode, that does not
require oracle client libraries to be installed in the system. The
``python-oracledb`` driver also support a "thick" mode, that behaves
similarly to ``cx_oracle`` and requires that Oracle Client Interface (OCI)
is installed.
To enable this mode, the user may call ``oracledb.init_oracle_client``
manually, or by passing the parameter ``thick_mode=True`` to
:func:`_sa.create_engine`. To pass custom arguments to ``init_oracle_client``,
like the ``lib_dir`` path, a dict may be passed to this parameter, as in::
engine = sa.create_engine("oracle+oracledb://...", thick_mode={
"lib_dir": "/path/to/oracle/client/lib", "driver_name": "my-app"
})
.. seealso::
https://python-oracledb.readthedocs.io/en/latest/api_manual/module.html#oracledb.init_oracle_client
Two Phase Transactions Supported
--------------------------------
Two phase transactions are fully supported under oracledb. Starting with
oracledb 2.3 two phase transactions are supported also in thin mode. APIs
for two phase transactions are provided at the Core level via
:meth:`_engine.Connection.begin_twophase` and :paramref:`_orm.Session.twophase`
for transparent ORM use.
.. versionchanged:: 2.0.32 added support for two phase transactions
.. versionadded:: 2.0.0 added support for oracledb driver.
""" # noqa
from __future__ import annotations
import collections
import re
from typing import Any
from typing import TYPE_CHECKING
from . import cx_oracle as _cx_oracle
from ... import exc
from ... import pool
from ...connectors.asyncio import AsyncAdapt_dbapi_connection
from ...connectors.asyncio import AsyncAdapt_dbapi_cursor
from ...connectors.asyncio import AsyncAdapt_dbapi_ss_cursor
from ...connectors.asyncio import AsyncAdaptFallback_dbapi_connection
from ...engine import default
from ...util import asbool
from ...util import await_fallback
from ...util import await_only
if TYPE_CHECKING:
from oracledb import AsyncConnection
from oracledb import AsyncCursor
class OracleExecutionContext_oracledb(
_cx_oracle.OracleExecutionContext_cx_oracle
):
pass
class OracleDialect_oracledb(_cx_oracle.OracleDialect_cx_oracle):
supports_statement_cache = True
execution_ctx_cls = OracleExecutionContext_oracledb
driver = "oracledb"
_min_version = (1,)
def __init__(
self,
auto_convert_lobs=True,
coerce_to_decimal=True,
arraysize=None,
encoding_errors=None,
thick_mode=None,
**kwargs,
):
super().__init__(
auto_convert_lobs,
coerce_to_decimal,
arraysize,
encoding_errors,
**kwargs,
)
if self.dbapi is not None and (
thick_mode or isinstance(thick_mode, dict)
):
kw = thick_mode if isinstance(thick_mode, dict) else {}
self.dbapi.init_oracle_client(**kw)
@classmethod
def import_dbapi(cls):
import oracledb
return oracledb
@classmethod
def is_thin_mode(cls, connection):
return connection.connection.dbapi_connection.thin
@classmethod
def get_async_dialect_cls(cls, url):
return OracleDialectAsync_oracledb
def _load_version(self, dbapi_module):
version = (0, 0, 0)
if dbapi_module is not None:
m = re.match(r"(\d+)\.(\d+)(?:\.(\d+))?", dbapi_module.version)
if m:
version = tuple(
int(x) for x in m.group(1, 2, 3) if x is not None
)
self.oracledb_ver = version
if (
self.oracledb_ver > (0, 0, 0)
and self.oracledb_ver < self._min_version
):
raise exc.InvalidRequestError(
f"oracledb version {self._min_version} and above are supported"
)
def do_begin_twophase(self, connection, xid):
conn_xis = connection.connection.xid(*xid)
connection.connection.tpc_begin(conn_xis)
connection.connection.info["oracledb_xid"] = conn_xis
def do_prepare_twophase(self, connection, xid):
should_commit = connection.connection.tpc_prepare()
connection.info["oracledb_should_commit"] = should_commit
def do_rollback_twophase(
self, connection, xid, is_prepared=True, recover=False
):
if recover:
conn_xid = connection.connection.xid(*xid)
else:
conn_xid = None
connection.connection.tpc_rollback(conn_xid)
def do_commit_twophase(
self, connection, xid, is_prepared=True, recover=False
):
conn_xid = None
if not is_prepared:
should_commit = connection.connection.tpc_prepare()
elif recover:
conn_xid = connection.connection.xid(*xid)
should_commit = True
else:
should_commit = connection.info["oracledb_should_commit"]
if should_commit:
connection.connection.tpc_commit(conn_xid)
def do_recover_twophase(self, connection):
return [
# oracledb seems to return bytes
(
fi,
gti.decode() if isinstance(gti, bytes) else gti,
bq.decode() if isinstance(bq, bytes) else bq,
)
for fi, gti, bq in connection.connection.tpc_recover()
]
class AsyncAdapt_oracledb_cursor(AsyncAdapt_dbapi_cursor):
_cursor: AsyncCursor
__slots__ = ()
@property
def outputtypehandler(self):
return self._cursor.outputtypehandler
@outputtypehandler.setter
def outputtypehandler(self, value):
self._cursor.outputtypehandler = value
def var(self, *args, **kwargs):
return self._cursor.var(*args, **kwargs)
def close(self):
self._rows.clear()
self._cursor.close()
def setinputsizes(self, *args: Any, **kwargs: Any) -> Any:
return self._cursor.setinputsizes(*args, **kwargs)
def _aenter_cursor(self, cursor: AsyncCursor) -> AsyncCursor:
try:
return cursor.__enter__()
except Exception as error:
self._adapt_connection._handle_exception(error)
async def _execute_async(self, operation, parameters):
# override to not use mutex, oracledb already has mutex
if parameters is None:
result = await self._cursor.execute(operation)
else:
result = await self._cursor.execute(operation, parameters)
if self._cursor.description and not self.server_side:
self._rows = collections.deque(await self._cursor.fetchall())
return result
async def _executemany_async(
self,
operation,
seq_of_parameters,
):
# override to not use mutex, oracledb already has mutex
return await self._cursor.executemany(operation, seq_of_parameters)
def __enter__(self):
return self
def __exit__(self, type_: Any, value: Any, traceback: Any) -> None:
self.close()
class AsyncAdapt_oracledb_ss_cursor(
AsyncAdapt_dbapi_ss_cursor, AsyncAdapt_oracledb_cursor
):
__slots__ = ()
def close(self) -> None:
if self._cursor is not None:
self._cursor.close()
self._cursor = None # type: ignore
class AsyncAdapt_oracledb_connection(AsyncAdapt_dbapi_connection):
_connection: AsyncConnection
__slots__ = ()
thin = True
_cursor_cls = AsyncAdapt_oracledb_cursor
_ss_cursor_cls = None
@property
def autocommit(self):
return self._connection.autocommit
@autocommit.setter
def autocommit(self, value):
self._connection.autocommit = value
@property
def outputtypehandler(self):
return self._connection.outputtypehandler
@outputtypehandler.setter
def outputtypehandler(self, value):
self._connection.outputtypehandler = value
@property
def version(self):
return self._connection.version
@property
def stmtcachesize(self):
return self._connection.stmtcachesize
@stmtcachesize.setter
def stmtcachesize(self, value):
self._connection.stmtcachesize = value
def cursor(self):
return AsyncAdapt_oracledb_cursor(self)
def ss_cursor(self):
return AsyncAdapt_oracledb_ss_cursor(self)
def xid(self, *args: Any, **kwargs: Any) -> Any:
return self._connection.xid(*args, **kwargs)
def tpc_begin(self, *args: Any, **kwargs: Any) -> Any:
return self.await_(self._connection.tpc_begin(*args, **kwargs))
def tpc_commit(self, *args: Any, **kwargs: Any) -> Any:
return self.await_(self._connection.tpc_commit(*args, **kwargs))
def tpc_prepare(self, *args: Any, **kwargs: Any) -> Any:
return self.await_(self._connection.tpc_prepare(*args, **kwargs))
def tpc_recover(self, *args: Any, **kwargs: Any) -> Any:
return self.await_(self._connection.tpc_recover(*args, **kwargs))
def tpc_rollback(self, *args: Any, **kwargs: Any) -> Any:
return self.await_(self._connection.tpc_rollback(*args, **kwargs))
class AsyncAdaptFallback_oracledb_connection(
AsyncAdaptFallback_dbapi_connection, AsyncAdapt_oracledb_connection
):
__slots__ = ()
class OracledbAdaptDBAPI:
def __init__(self, oracledb) -> None:
self.oracledb = oracledb
for k, v in self.oracledb.__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.oracledb.connect_async)
if asbool(async_fallback):
return AsyncAdaptFallback_oracledb_connection(
self, await_fallback(creator_fn(*arg, **kw))
)
else:
return AsyncAdapt_oracledb_connection(
self, await_only(creator_fn(*arg, **kw))
)
class OracleExecutionContextAsync_oracledb(OracleExecutionContext_oracledb):
# restore default create cursor
create_cursor = default.DefaultExecutionContext.create_cursor
def create_default_cursor(self):
# copy of OracleExecutionContext_cx_oracle.create_cursor
c = self._dbapi_connection.cursor()
if self.dialect.arraysize:
c.arraysize = self.dialect.arraysize
return c
def create_server_side_cursor(self):
c = self._dbapi_connection.ss_cursor()
if self.dialect.arraysize:
c.arraysize = self.dialect.arraysize
return c
class OracleDialectAsync_oracledb(OracleDialect_oracledb):
is_async = True
supports_server_side_cursors = True
supports_statement_cache = True
execution_ctx_cls = OracleExecutionContextAsync_oracledb
_min_version = (2,)
# thick_mode mode is not supported by asyncio, oracledb will raise
@classmethod
def import_dbapi(cls):
import oracledb
return OracledbAdaptDBAPI(oracledb)
@classmethod
def get_pool_class(cls, url):
async_fallback = url.query.get("async_fallback", False)
if asbool(async_fallback):
return pool.FallbackAsyncAdaptedQueuePool
else:
return pool.AsyncAdaptedQueuePool
def get_driver_connection(self, connection):
return connection._connection
dialect = OracleDialect_oracledb
dialect_async = OracleDialectAsync_oracledb
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