# Copyright (C) 2005-2019 the SQLAlchemy authors and contributors # # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php r""" .. dialect:: oracle+cx_oracle :name: cx-Oracle :dbapi: cx_oracle :connectstring: oracle+cx_oracle://user:pass@host:port/dbname[?key=value&key=value...] :url: https://oracle.github.io/python-cx_Oracle/ Additional Connect Arguments ---------------------------- When connecting with the ``dbname`` URL token present, the ``hostname``, ``port``, and ``dbname`` tokens are converted to a TNS name using the ``cx_Oracle.makedsn()`` function. The URL below:: e = create_engine("oracle+cx_oracle://user:pass@hostname/dbname") Will be used to create the DSN as follows:: >>> import cx_Oracle >>> cx_Oracle.makedsn("hostname", 1521, sid="dbname") '(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=hostname)(PORT=1521))(CONNECT_DATA=(SID=dbname)))' The ``service_name`` parameter, also consumed by ``cx_Oracle.makedsn()``, may be specified in the URL query string, e.g. ``?service_name=my_service``. If ``dbname`` is not present, then the value of ``hostname`` in the URL is used directly as the DSN passed to ``cx_Oracle.connect()``. Additional connection arguments may be sent to the ``cx_Oracle.connect()`` function using the :paramref:`.create_engine.connect_args` dictionary. Any cx_Oracle parameter value and/or constant may be passed, such as:: import cx_Oracle e = create_engine( "oracle+cx_oracle://user:pass@dsn", connect_args={ "mode": cx_Oracle.SYSDBA, "events": True } ) There are also options that are consumed by the SQLAlchemy cx_oracle dialect itself. These options are always passed directly to :func:`.create_engine`, such as:: e = create_engine( "oracle+cx_oracle://user:pass@dsn", coerce_to_unicode=False) The parameters accepted by the cx_oracle dialect are as follows: * ``arraysize`` - set the cx_oracle.arraysize value on cursors, defaulted to 50. This setting is significant with cx_Oracle as the contents of LOB objects are only readable within a "live" row (e.g. within a batch of 50 rows). * ``auto_convert_lobs`` - defaults to True; See :ref:`cx_oracle_lob`. * ``coerce_to_unicode`` - see :ref:`cx_oracle_unicode` for detail. * ``coerce_to_decimal`` - see :ref:`cx_oracle_numeric` for detail. * ``threaded`` - this parameter is passed as the value of "threaded" to ``cx_Oracle.connect()`` and defaults to True, which is the opposite of cx_Oracle's default. This parameter is deprecated and will default to ``False`` in version 1.3 of SQLAlchemy. .. _cx_oracle_unicode: Unicode ------- The cx_Oracle DBAPI as of version 5 fully supports unicode, and has the ability to return string results as Python unicode objects natively. When used in Python 3, cx_Oracle returns all strings as Python unicode objects (that is, plain ``str`` in Python 3). In Python 2, it will return as Python unicode those column values that are of type ``NVARCHAR`` or ``NCLOB``. For column values that are of type ``VARCHAR`` or other non-unicode string types, it will return values as Python strings (e.g. bytestrings). The cx_Oracle SQLAlchemy dialect presents several different options for the use case of receiving ``VARCHAR`` column values as Python unicode objects under Python 2: * When using Core expression objects as well as the ORM, SQLAlchemy's unicode-decoding services are available, which are established by using either the :class:`.Unicode` datatype or by using the :class:`.String` datatype with :paramref:`.String.convert_unicode` set to True. * When using raw SQL strings, typing behavior can be added for unicode conversion using the :func:`.text` construct:: from sqlalchemy import text, Unicode result = conn.execute( text("select username from user").columns(username=Unicode)) * Otherwise, when using raw SQL strings sent directly to an ``.execute()`` method without any Core typing behavior added, the flag ``coerce_to_unicode=True`` flag can be passed to :func:`.create_engine` which will add an unconditional unicode processor to cx_Oracle for all string values:: engine = create_engine("oracle+cx_oracle://dsn", coerce_to_unicode=True) The above approach will add significant latency to result-set fetches of plain string values. Sending String Values as Unicode or Non-Unicode ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ As of SQLAlchemy 1.2.2, the cx_Oracle dialect unconditionally calls ``setinputsizes()`` for bound values that are passed as Python unicode objects. In Python 3, all string values are Unicode; for cx_Oracle, this corresponds to ``cx_Oracle.NCHAR`` being passed to ``setinputsizes()`` for that parameter. In some edge cases, such as passing format specifiers for the ``trunc()`` function, Oracle does not accept these as NCHAR:: from sqlalchemy import func conn.execute( func.trunc(func.sysdate(), 'dd') ) In these cases, an error as follows may be raised:: ORA-01899: bad precision specifier When this error is encountered, it may be necessary to pass the string value with an explicit non-unicode type:: from sqlalchemy import func from sqlalchemy import literal from sqlalchemy import String conn.execute( func.trunc(func.sysdate(), literal('dd', String)) ) For full control over this ``setinputsizes()`` behavior, see the section :ref:`cx_oracle_setinputsizes` .. _cx_oracle_setinputsizes: Fine grained control over cx_Oracle data binding performance with setinputsizes ------------------------------------------------------------------------------- The cx_Oracle DBAPI has a deep and fundamental reliance upon the usage of the DBAPI ``setinputsizes()`` call. The purpose of this call is to establish the datatypes that are bound to a SQL statement for Python values being passed as parameters. While virtually no other DBAPI assigns any use to the ``setinputsizes()`` call, the cx_Oracle DBAPI relies upon it heavily in its interactions with the Oracle client interface, and in some scenarios it is not possible for SQLAlchemy to know exactly how data should be bound, as some settings can cause profoundly different performance characteristics, while altering the type coercion behavior at the same time. Users of the cx_Oracle dialect are **strongly encouraged** to read through cx_Oracle's list of built-in datatype symbols at http://cx-oracle.readthedocs.io/en/latest/module.html#types. Note that in some cases, significant performance degradation can occur when using these types vs. not, in particular when specifying ``cx_Oracle.CLOB``. On the SQLAlchemy side, the :meth:`.DialectEvents.do_setinputsizes` event can be used both for runtime visibility (e.g. logging) of the setinputsizes step as well as to fully control how ``setinputsizes()`` is used on a per-statement basis. .. versionadded:: 1.2.9 Added :meth:`.DialectEvents.setinputsizes` Example 1 - logging all setinputsizes calls ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The following example illustrates how to log the intermediary values from a SQLAlchemy perspective before they are converted to the raw ``setinputsizes()`` parameter dictionary. The keys of the dictionary are :class:`.BindParameter` objects which have a ``.key`` and a ``.type`` attribute:: from sqlalchemy import create_engine, event engine = create_engine("oracle+cx_oracle://scott:tiger@host/xe") @event.listens_for(engine, "do_setinputsizes") def _log_setinputsizes(inputsizes, cursor, statement, parameters, context): for bindparam, dbapitype in inputsizes.items(): log.info( "Bound parameter name: %s SQLAlchemy type: %r " "DBAPI object: %s", bindparam.key, bindparam.type, dbapitype) Example 2 - remove all bindings to CLOB ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The ``CLOB`` datatype in cx_Oracle incurs a significant performance overhead, however is set by default for the ``Text`` type within the SQLAlchemy 1.2 series. This setting can be modified as follows:: from sqlalchemy import create_engine, event from cx_Oracle import CLOB engine = create_engine("oracle+cx_oracle://scott:tiger@host/xe") @event.listens_for(engine, "do_setinputsizes") def _remove_clob(inputsizes, cursor, statement, parameters, context): for bindparam, dbapitype in list(inputsizes.items()): if dbapitype is CLOB: del inputsizes[bindparam] .. _cx_oracle_returning: RETURNING Support ----------------- The cx_Oracle dialect implements RETURNING using OUT parameters. The dialect supports RETURNING fully, however cx_Oracle 6 is recommended for complete support. .. _cx_oracle_lob: LOB Objects ----------- cx_oracle returns oracle LOBs using the cx_oracle.LOB object. SQLAlchemy converts these to strings so that the interface of the Binary type is consistent with that of other backends, which takes place within a cx_Oracle outputtypehandler. cx_Oracle prior to version 6 would require that LOB objects be read before a new batch of rows would be read, as determined by the ``cursor.arraysize``. As of the 6 series, this limitation has been lifted. Nevertheless, because SQLAlchemy pre-reads these LOBs up front, this issue is avoided in any case. To disable the auto "read()" feature of the dialect, the flag ``auto_convert_lobs=False`` may be passed to :func:`.create_engine`. Under the cx_Oracle 5 series, having this flag turned off means there is the chance of reading from a stale LOB object if not read as it is fetched. With cx_Oracle 6, this issue is resolved. .. versionchanged:: 1.2 the LOB handling system has been greatly simplified internally to make use of outputtypehandlers, and no longer makes use of alternate "buffered" result set objects. Two Phase Transactions Not Supported ------------------------------------- Two phase transactions are **not supported** under cx_Oracle due to poor driver support. As of cx_Oracle 6.0b1, the interface for two phase transactions has been changed to be more of a direct pass-through to the underlying OCI layer with less automation. The additional logic to support this system is not implemented in SQLAlchemy. .. _cx_oracle_numeric: Precision Numerics ------------------ SQLAlchemy's numeric types can handle receiving and returning values as Python ``Decimal`` objects or float objects. When a :class:`.Numeric` object, or a subclass such as :class:`.Float`, :class:`.oracle.DOUBLE_PRECISION` etc. is in use, the :paramref:`.Numeric.asdecimal` flag determines if values should be coerced to ``Decimal`` upon return, or returned as float objects. To make matters more complicated under Oracle, Oracle's ``NUMBER`` type can also represent integer values if the "scale" is zero, so the Oracle-specific :class:`.oracle.NUMBER` type takes this into account as well. The cx_Oracle dialect makes extensive use of connection- and cursor-level "outputtypehandler" callables in order to coerce numeric values as requested. These callables are specific to the specific flavor of :class:`.Numeric` in use, as well as if no SQLAlchemy typing objects are present. There are observed scenarios where Oracle may sends incomplete or ambiguous information about the numeric types being returned, such as a query where the numeric types are buried under multiple levels of subquery. The type handlers do their best to make the right decision in all cases, deferring to the underlying cx_Oracle DBAPI for all those cases where the driver can make the best decision. When no typing objects are present, as when executing plain SQL strings, a default "outputtypehandler" is present which will generally return numeric values which specify precision and scale as Python ``Decimal`` objects. To disable this coercion to decimal for performance reasons, pass the flag ``coerce_to_decimal=False`` to :func:`.create_engine`:: engine = create_engine("oracle+cx_oracle://dsn", coerce_to_decimal=False) The ``coerce_to_decimal`` flag only impacts the results of plain string SQL staements that are not otherwise associated with a :class:`.Numeric` SQLAlchemy type (or a subclass of such). .. versionchanged:: 1.2 The numeric handling system for cx_Oracle has been reworked to take advantage of newer cx_Oracle features as well as better integration of outputtypehandlers. """ # noqa from __future__ import absolute_import import collections import decimal import random import re from . import base as oracle from .base import OracleCompiler from .base import OracleDialect from .base import OracleExecutionContext from ... import exc from ... import processors from ... import types as sqltypes from ... import util from ...engine import result as _result class _OracleInteger(sqltypes.Integer): def get_dbapi_type(self, dbapi): # see https://github.com/oracle/python-cx_Oracle/issues/ # 208#issuecomment-409715955 return int def _cx_oracle_var(self, dialect, cursor): cx_Oracle = dialect.dbapi return cursor.var( cx_Oracle.STRING, 255, arraysize=cursor.arraysize, outconverter=int ) def _cx_oracle_outputtypehandler(self, dialect): def handler(cursor, name, default_type, size, precision, scale): return self._cx_oracle_var(dialect, cursor) return handler class _OracleNumeric(sqltypes.Numeric): is_number = False def bind_processor(self, dialect): if self.scale == 0: return None elif self.asdecimal: processor = processors.to_decimal_processor_factory( decimal.Decimal, self._effective_decimal_return_scale ) def process(value): if isinstance(value, (int, float)): return processor(value) elif value is not None and value.is_infinite(): return float(value) else: return value return process else: return processors.to_float def result_processor(self, dialect, coltype): return None def _cx_oracle_outputtypehandler(self, dialect): cx_Oracle = dialect.dbapi is_cx_oracle_6 = dialect._is_cx_oracle_6 def handler(cursor, name, default_type, size, precision, scale): outconverter = None if precision: if self.asdecimal: if default_type == cx_Oracle.NATIVE_FLOAT: # receiving float and doing Decimal after the fact # allows for float("inf") to be handled type_ = default_type outconverter = decimal.Decimal elif is_cx_oracle_6: type_ = decimal.Decimal else: type_ = cx_Oracle.STRING outconverter = dialect._to_decimal else: if self.is_number and scale == 0: # integer. cx_Oracle is observed to handle the widest # variety of ints when no directives are passed, # from 5.2 to 7.0. See [ticket:4457] return None else: type_ = cx_Oracle.NATIVE_FLOAT else: if self.asdecimal: if default_type == cx_Oracle.NATIVE_FLOAT: type_ = default_type outconverter = decimal.Decimal elif is_cx_oracle_6: type_ = decimal.Decimal else: type_ = cx_Oracle.STRING outconverter = dialect._to_decimal else: if self.is_number and scale == 0: # integer. cx_Oracle is observed to handle the widest # variety of ints when no directives are passed, # from 5.2 to 7.0. See [ticket:4457] return None else: type_ = cx_Oracle.NATIVE_FLOAT return cursor.var( type_, 255, arraysize=cursor.arraysize, outconverter=outconverter, ) return handler class _OracleBinaryFloat(_OracleNumeric): def get_dbapi_type(self, dbapi): return dbapi.NATIVE_FLOAT class _OracleBINARY_FLOAT(_OracleBinaryFloat, oracle.BINARY_FLOAT): pass class _OracleBINARY_DOUBLE(_OracleBinaryFloat, oracle.BINARY_DOUBLE): pass class _OracleNUMBER(_OracleNumeric): is_number = True class _OracleDate(sqltypes.Date): def bind_processor(self, dialect): return None def result_processor(self, dialect, coltype): def process(value): if value is not None: return value.date() else: return value return process class _OracleChar(sqltypes.CHAR): def get_dbapi_type(self, dbapi): return dbapi.FIXED_CHAR class _OracleNVarChar(sqltypes.NVARCHAR): def get_dbapi_type(self, dbapi): return dbapi.NCHAR class _OracleText(sqltypes.Text): def get_dbapi_type(self, dbapi): return dbapi.CLOB class _OracleLong(oracle.LONG): def get_dbapi_type(self, dbapi): return dbapi.LONG_STRING class _OracleString(sqltypes.String): pass class _OracleEnum(sqltypes.Enum): def bind_processor(self, dialect): enum_proc = sqltypes.Enum.bind_processor(self, dialect) def process(value): raw_str = enum_proc(value) return raw_str return process class _OracleUnicodeText(sqltypes.UnicodeText): def get_dbapi_type(self, dbapi): return dbapi.NCLOB class _OracleBinary(sqltypes.LargeBinary): def get_dbapi_type(self, dbapi): return dbapi.BLOB def bind_processor(self, dialect): return None def result_processor(self, dialect, coltype): if not dialect.auto_convert_lobs: return None else: return super(_OracleBinary, self).result_processor( dialect, coltype ) class _OracleInterval(oracle.INTERVAL): def get_dbapi_type(self, dbapi): return dbapi.INTERVAL class _OracleRaw(oracle.RAW): pass class _OracleRowid(oracle.ROWID): def get_dbapi_type(self, dbapi): return dbapi.ROWID class OracleCompiler_cx_oracle(OracleCompiler): _oracle_cx_sql_compiler = True def bindparam_string(self, name, **kw): quote = getattr(name, "quote", None) if ( quote is True or quote is not False and self.preparer._bindparam_requires_quotes(name) ): if kw.get("expanding", False): raise exc.CompileError( "Can't use expanding feature with parameter name " "%r on Oracle; it requires quoting which is not supported " "in this context." % name ) quoted_name = '"%s"' % name self._quoted_bind_names[name] = quoted_name return OracleCompiler.bindparam_string(self, quoted_name, **kw) else: return OracleCompiler.bindparam_string(self, name, **kw) class OracleExecutionContext_cx_oracle(OracleExecutionContext): out_parameters = None def _setup_quoted_bind_names(self): quoted_bind_names = self.compiled._quoted_bind_names if quoted_bind_names: for param in self.parameters: for fromname, toname in quoted_bind_names.items(): param[toname] = param[fromname] del param[fromname] def _handle_out_parameters(self): # if a single execute, check for outparams if len(self.compiled_parameters) == 1: quoted_bind_names = self.compiled._quoted_bind_names for bindparam in self.compiled.binds.values(): if bindparam.isoutparam: name = self.compiled.bind_names[bindparam] type_impl = bindparam.type.dialect_impl(self.dialect) if hasattr(type_impl, "_cx_oracle_var"): self.out_parameters[name] = type_impl._cx_oracle_var( self.dialect, self.cursor ) else: dbtype = type_impl.get_dbapi_type(self.dialect.dbapi) if dbtype is None: raise exc.InvalidRequestError( "Cannot create out parameter for parameter " "%r - its type %r is not supported by" " cx_oracle" % (bindparam.key, bindparam.type) ) self.out_parameters[name] = self.cursor.var(dbtype) self.parameters[0][ quoted_bind_names.get(name, name) ] = self.out_parameters[name] def _generate_cursor_outputtype_handler(self): output_handlers = {} for (keyname, name, objects, type_) in self.compiled._result_columns: handler = type_._cached_custom_processor( self.dialect, "cx_oracle_outputtypehandler", self._get_cx_oracle_type_handler, ) if handler: denormalized_name = self.dialect.denormalize_name(keyname) output_handlers[denormalized_name] = handler if output_handlers: default_handler = self._dbapi_connection.outputtypehandler def output_type_handler( cursor, name, default_type, size, precision, scale ): if name in output_handlers: return output_handlers[name]( cursor, name, default_type, size, precision, scale ) else: return default_handler( cursor, name, default_type, size, precision, scale ) self.cursor.outputtypehandler = output_type_handler def _get_cx_oracle_type_handler(self, impl): if hasattr(impl, "_cx_oracle_outputtypehandler"): return impl._cx_oracle_outputtypehandler(self.dialect) else: return None def pre_exec(self): if not getattr(self.compiled, "_oracle_cx_sql_compiler", False): return self.out_parameters = {} if self.compiled._quoted_bind_names: self._setup_quoted_bind_names() self.set_input_sizes( self.compiled._quoted_bind_names, include_types=self.dialect._include_setinputsizes, ) self._handle_out_parameters() self._generate_cursor_outputtype_handler() def create_cursor(self): c = self._dbapi_connection.cursor() if self.dialect.arraysize: c.arraysize = self.dialect.arraysize return c def get_result_proxy(self): if self.out_parameters and self.compiled.returning: returning_params = [ self.dialect._returningval(self.out_parameters["ret_%d" % i]) for i in range(len(self.out_parameters)) ] return ReturningResultProxy(self, returning_params) result = _result.ResultProxy(self) if self.out_parameters: if ( self.compiled_parameters is not None and len(self.compiled_parameters) == 1 ): result.out_parameters = out_parameters = {} for bind, name in self.compiled.bind_names.items(): if name in self.out_parameters: type_ = bind.type impl_type = type_.dialect_impl(self.dialect) dbapi_type = impl_type.get_dbapi_type( self.dialect.dbapi ) result_processor = impl_type.result_processor( self.dialect, dbapi_type ) if result_processor is not None: out_parameters[name] = result_processor( self.dialect._paramval( self.out_parameters[name] ) ) else: out_parameters[name] = self.dialect._paramval( self.out_parameters[name] ) else: result.out_parameters = dict( (k, self._dialect._paramval(v)) for k, v in self.out_parameters.items() ) return result class ReturningResultProxy(_result.FullyBufferedResultProxy): """Result proxy which stuffs the _returning clause + outparams into the fetch.""" def __init__(self, context, returning_params): self._returning_params = returning_params super(ReturningResultProxy, self).__init__(context) def _cursor_description(self): returning = self.context.compiled.returning return [ (getattr(col, "name", col.anon_label), None) for col in returning ] def _buffer_rows(self): return collections.deque([tuple(self._returning_params)]) class OracleDialect_cx_oracle(OracleDialect): execution_ctx_cls = OracleExecutionContext_cx_oracle statement_compiler = OracleCompiler_cx_oracle supports_sane_rowcount = True supports_sane_multi_rowcount = True supports_unicode_statements = True supports_unicode_binds = True driver = "cx_oracle" colspecs = { sqltypes.Numeric: _OracleNumeric, sqltypes.Float: _OracleNumeric, oracle.BINARY_FLOAT: _OracleBINARY_FLOAT, oracle.BINARY_DOUBLE: _OracleBINARY_DOUBLE, sqltypes.Integer: _OracleInteger, oracle.NUMBER: _OracleNUMBER, sqltypes.Date: _OracleDate, sqltypes.LargeBinary: _OracleBinary, sqltypes.Boolean: oracle._OracleBoolean, sqltypes.Interval: _OracleInterval, oracle.INTERVAL: _OracleInterval, sqltypes.Text: _OracleText, sqltypes.String: _OracleString, sqltypes.UnicodeText: _OracleUnicodeText, sqltypes.CHAR: _OracleChar, sqltypes.Enum: _OracleEnum, oracle.LONG: _OracleLong, oracle.RAW: _OracleRaw, sqltypes.Unicode: _OracleNVarChar, sqltypes.NVARCHAR: _OracleNVarChar, oracle.ROWID: _OracleRowid, } execute_sequence_format = list def __init__( self, auto_convert_lobs=True, threaded=True, coerce_to_unicode=False, coerce_to_decimal=True, arraysize=50, **kwargs ): self._pop_deprecated_kwargs(kwargs) OracleDialect.__init__(self, **kwargs) self.threaded = threaded self.arraysize = arraysize self.auto_convert_lobs = auto_convert_lobs self.coerce_to_unicode = coerce_to_unicode self.coerce_to_decimal = coerce_to_decimal cx_Oracle = self.dbapi if cx_Oracle is None: self._include_setinputsizes = {} self.cx_oracle_ver = (0, 0, 0) else: self.cx_oracle_ver = self._parse_cx_oracle_ver(cx_Oracle.version) if self.cx_oracle_ver < (5, 2) and self.cx_oracle_ver > (0, 0, 0): raise exc.InvalidRequestError( "cx_Oracle version 5.2 and above are supported" ) self._include_setinputsizes = { cx_Oracle.NCLOB, cx_Oracle.CLOB, cx_Oracle.LOB, cx_Oracle.NCHAR, cx_Oracle.FIXED_NCHAR, cx_Oracle.BLOB, cx_Oracle.FIXED_CHAR, cx_Oracle.TIMESTAMP, _OracleInteger, _OracleBINARY_FLOAT, _OracleBINARY_DOUBLE, } self._paramval = lambda value: value.getvalue() # https://github.com/oracle/python-cx_Oracle/issues/176#issuecomment-386821291 # https://github.com/oracle/python-cx_Oracle/issues/224 self._values_are_lists = self.cx_oracle_ver >= (6, 3) if self._values_are_lists: cx_Oracle.__future__.dml_ret_array_val = True def _returningval(value): try: return value.values[0][0] except IndexError: return None self._returningval = _returningval else: self._returningval = self._paramval self._is_cx_oracle_6 = self.cx_oracle_ver >= (6,) def _pop_deprecated_kwargs(self, kwargs): auto_setinputsizes = kwargs.pop("auto_setinputsizes", None) exclude_setinputsizes = kwargs.pop("exclude_setinputsizes", None) if auto_setinputsizes or exclude_setinputsizes: util.warn_deprecated( "auto_setinputsizes and exclude_setinputsizes are deprecated. " "Modern cx_Oracle only requires that LOB types are part " "of this behavior, and these parameters no longer have any " "effect." ) allow_twophase = kwargs.pop("allow_twophase", None) if allow_twophase is not None: util.warn.deprecated( "allow_twophase is deprecated. The cx_Oracle dialect no " "longer supports two-phase transaction mode." ) def _parse_cx_oracle_ver(self, version): m = re.match(r"(\d+)\.(\d+)(?:\.(\d+))?", version) if m: return tuple(int(x) for x in m.group(1, 2, 3) if x is not None) else: return (0, 0, 0) @classmethod def dbapi(cls): import cx_Oracle return cx_Oracle def initialize(self, connection): super(OracleDialect_cx_oracle, self).initialize(connection) if self._is_oracle_8: self.supports_unicode_binds = False self._detect_decimal_char(connection) def _detect_decimal_char(self, connection): # we have the option to change this setting upon connect, # or just look at what it is upon connect and convert. # to minimize the chance of interference with changes to # NLS_TERRITORY or formatting behavior of the DB, we opt # to just look at it self._decimal_char = connection.scalar( "select value from nls_session_parameters " "where parameter = 'NLS_NUMERIC_CHARACTERS'" )[0] if self._decimal_char != ".": _detect_decimal = self._detect_decimal _to_decimal = self._to_decimal self._detect_decimal = lambda value: _detect_decimal( value.replace(self._decimal_char, ".") ) self._to_decimal = lambda value: _to_decimal( value.replace(self._decimal_char, ".") ) def _detect_decimal(self, value): if "." in value: return self._to_decimal(value) else: return int(value) _to_decimal = decimal.Decimal def _generate_connection_outputtype_handler(self): """establish the default outputtypehandler established at the connection level. """ dialect = self cx_Oracle = dialect.dbapi number_handler = _OracleNUMBER( asdecimal=True )._cx_oracle_outputtypehandler(dialect) float_handler = _OracleNUMBER( asdecimal=False )._cx_oracle_outputtypehandler(dialect) def output_type_handler( cursor, name, default_type, size, precision, scale ): if default_type == cx_Oracle.NUMBER: if not dialect.coerce_to_decimal: return None elif precision == 0 and scale in (0, -127): # ambiguous type, this occurs when selecting # numbers from deep subqueries return cursor.var( cx_Oracle.STRING, 255, outconverter=dialect._detect_decimal, arraysize=cursor.arraysize, ) elif precision and scale > 0: return number_handler( cursor, name, default_type, size, precision, scale ) else: return float_handler( cursor, name, default_type, size, precision, scale ) # allow all strings to come back natively as Unicode elif dialect.coerce_to_unicode and default_type in ( cx_Oracle.STRING, cx_Oracle.FIXED_CHAR, ): return cursor.var(util.text_type, size, cursor.arraysize) elif dialect.auto_convert_lobs and default_type in ( cx_Oracle.CLOB, cx_Oracle.NCLOB, cx_Oracle.BLOB, ): return cursor.var( default_type, size, cursor.arraysize, outconverter=lambda value: value.read(), ) return output_type_handler def on_connect(self): output_type_handler = self._generate_connection_outputtype_handler() def on_connect(conn): conn.outputtypehandler = output_type_handler return on_connect def create_connect_args(self, url): dialect_opts = dict(url.query) for opt in ( "use_ansi", "auto_setinputsizes", "auto_convert_lobs", "threaded", "allow_twophase", ): if opt in dialect_opts: util.coerce_kw_type(dialect_opts, opt, bool) setattr(self, opt, dialect_opts[opt]) database = url.database service_name = dialect_opts.get("service_name", None) if database or service_name: # if we have a database, then we have a remote host port = url.port if port: port = int(port) else: port = 1521 if database and service_name: raise exc.InvalidRequestError( '"service_name" option shouldn\'t ' 'be used with a "database" part of the url' ) if database: makedsn_kwargs = {"sid": database} if service_name: makedsn_kwargs = {"service_name": service_name} dsn = self.dbapi.makedsn(url.host, port, **makedsn_kwargs) else: # we have a local tnsname dsn = url.host opts = dict(threaded=self.threaded) if dsn is not None: opts["dsn"] = dsn if url.password is not None: opts["password"] = url.password if url.username is not None: opts["user"] = url.username if "mode" in url.query: opts["mode"] = url.query["mode"] if isinstance(opts["mode"], util.string_types): mode = opts["mode"].upper() if mode == "SYSDBA": opts["mode"] = self.dbapi.SYSDBA elif mode == "SYSOPER": opts["mode"] = self.dbapi.SYSOPER else: util.coerce_kw_type(opts, "mode", int) return ([], opts) def _get_server_version_info(self, connection): return tuple(int(x) for x in connection.connection.version.split(".")) def is_disconnect(self, e, connection, cursor): error, = e.args if isinstance( e, (self.dbapi.InterfaceError, self.dbapi.DatabaseError) ) and "not connected" in str(e): return True if hasattr(error, "code"): # ORA-00028: your session has been killed # ORA-03114: not connected to ORACLE # ORA-03113: end-of-file on communication channel # ORA-03135: connection lost contact # ORA-01033: ORACLE initialization or shutdown in progress # ORA-02396: exceeded maximum idle time, please connect again # TODO: Others ? return error.code in (28, 3114, 3113, 3135, 1033, 2396) else: return False def create_xid(self): """create a two-phase transaction ID. this id will be passed to do_begin_twophase(), do_rollback_twophase(), do_commit_twophase(). its format is unspecified. .. deprecated:: two-phase transaction support is no longer functional in SQLAlchemy's cx_Oracle dialect as of cx_Oracle 6.0b1 """ id_ = random.randint(0, 2 ** 128) return (0x1234, "%032x" % id_, "%032x" % 9) def do_executemany(self, cursor, statement, parameters, context=None): if isinstance(parameters, tuple): parameters = list(parameters) cursor.executemany(statement, parameters) def do_begin_twophase(self, connection, xid): connection.connection.begin(*xid) def do_prepare_twophase(self, connection, xid): result = connection.connection.prepare() connection.info["cx_oracle_prepared"] = result def do_rollback_twophase( self, connection, xid, is_prepared=True, recover=False ): self.do_rollback(connection.connection) def do_commit_twophase( self, connection, xid, is_prepared=True, recover=False ): if not is_prepared: self.do_commit(connection.connection) else: oci_prepared = connection.info["cx_oracle_prepared"] if oci_prepared: self.do_commit(connection.connection) def do_recover_twophase(self, connection): connection.info.pop("cx_oracle_prepared", None) dialect = OracleDialect_cx_oracle