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📁 ..	-	2026-03-21 15:45
📄 __init__.py # oracle/__init__.py # Copyright (C) 2005-2021 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php from . import base # noqa from . import cx_oracle # noqa from . import zxjdbc # noqa from .base import BFILE from .base import BINARY_DOUBLE from .base import BINARY_FLOAT from .base import BLOB from .base import CHAR from .base import CLOB from .base import DATE from .base import DOUBLE_PRECISION from .base import FLOAT from .base import INTERVAL from .base import LONG from .base import NCHAR from .base import NCLOB from .base import NUMBER from .base import NVARCHAR from .base import NVARCHAR2 from .base import RAW from .base import ROWID from .base import TIMESTAMP from .base import VARCHAR from .base import VARCHAR2 base.dialect = dialect = cx_oracle.dialect __all__ = ( "VARCHAR", "NVARCHAR", "CHAR", "NCHAR", "DATE", "NUMBER", "BLOB", "BFILE", "CLOB", "NCLOB", "TIMESTAMP", "RAW", "FLOAT", "DOUBLE_PRECISION", "BINARY_DOUBLE", "BINARY_FLOAT", "LONG", "dialect", "INTERVAL", "VARCHAR2", "NVARCHAR2", "ROWID", )	1.23 KB	2026-01-20 12:58
📁 __pycache__	-	2026-03-21 15:45
📄 base.py # oracle/base.py # Copyright (C) 2005-2021 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php r""" .. dialect:: oracle :name: Oracle Oracle version 8 through current (11g at the time of this writing) are supported. Auto Increment Behavior ----------------------- SQLAlchemy Table objects which include integer primary keys are usually assumed to have "autoincrementing" behavior, meaning they can generate their own primary key values upon INSERT. Since Oracle has no "autoincrement" feature, SQLAlchemy relies upon sequences to produce these values. With the Oracle dialect, a sequence must always be explicitly specified to enable autoincrement. This is divergent with the majority of documentation examples which assume the usage of an autoincrement-capable database. To specify sequences, use the sqlalchemy.schema.Sequence object which is passed to a Column construct:: t = Table('mytable', metadata, Column('id', Integer, Sequence('id_seq'), primary_key=True), Column(...), ... ) This step is also required when using table reflection, i.e. autoload=True:: t = Table('mytable', metadata, Column('id', Integer, Sequence('id_seq'), primary_key=True), autoload=True ) .. _oracle_isolation_level: Transaction Isolation Level / Autocommit ---------------------------------------- The Oracle database supports "READ COMMITTED" and "SERIALIZABLE" modes of isolation. The AUTOCOMMIT isolation level is also supported by the cx_Oracle dialect. To set using per-connection execution options:: connection = engine.connect() connection = connection.execution_options( isolation_level="AUTOCOMMIT" ) For ``READ COMMITTED`` and ``SERIALIZABLE``, the Oracle dialect sets the level at the session level using ``ALTER SESSION``, which is reverted back to its default setting when the connection is returned to the connection pool. Valid values for ``isolation_level`` include: * ``READ COMMITTED`` * ``AUTOCOMMIT`` * ``SERIALIZABLE`` .. note:: The implementation for the :meth:`_engine.Connection.get_isolation_level` method as implemented by the Oracle dialect necessarily forces the start of a transaction using the Oracle LOCAL_TRANSACTION_ID function; otherwise no level is normally readable. Additionally, the :meth:`_engine.Connection.get_isolation_level` method will raise an exception if the ``v$transaction`` view is not available due to permissions or other reasons, which is a common occurrence in Oracle installations. The cx_Oracle dialect attempts to call the :meth:`_engine.Connection.get_isolation_level` method when the dialect makes its first connection to the database in order to acquire the "default"isolation level. This default level is necessary so that the level can be reset on a connection after it has been temporarily modified using :meth:`_engine.Connection.execution_options` method. In the common event that the :meth:`_engine.Connection.get_isolation_level` method raises an exception due to ``v$transaction`` not being readable as well as any other database-related failure, the level is assumed to be "READ COMMITTED". No warning is emitted for this initial first-connect condition as it is expected to be a common restriction on Oracle databases. .. versionadded:: 1.3.16 added support for AUTOCOMMIT to the cx_oracle dialect as well as the notion of a default isolation level .. versionadded:: 1.3.21 Added support for SERIALIZABLE as well as live reading of the isolation level. .. versionchanged:: 1.3.22 In the event that the default isolation level cannot be read due to permissions on the v$transaction view as is common in Oracle installations, the default isolation level is hardcoded to "READ COMMITTED" which was the behavior prior to 1.3.21. .. seealso:: :ref:`dbapi_autocommit` Identifier Casing ----------------- In Oracle, the data dictionary represents all case insensitive identifier names using UPPERCASE text. SQLAlchemy on the other hand considers an all-lower case identifier name to be case insensitive. The Oracle dialect converts all case insensitive identifiers to and from those two formats during schema level communication, such as reflection of tables and indexes. Using an UPPERCASE name on the SQLAlchemy side indicates a case sensitive identifier, and SQLAlchemy will quote the name - this will cause mismatches against data dictionary data received from Oracle, so unless identifier names have been truly created as case sensitive (i.e. using quoted names), all lowercase names should be used on the SQLAlchemy side. .. _oracle_max_identifier_lengths: Max Identifier Lengths ---------------------- Oracle has changed the default max identifier length as of Oracle Server version 12.2. Prior to this version, the length was 30, and for 12.2 and greater it is now 128. This change impacts SQLAlchemy in the area of generated SQL label names as well as the generation of constraint names, particularly in the case where the constraint naming convention feature described at :ref:`constraint_naming_conventions` is being used. To assist with this change and others, Oracle includes the concept of a "compatibility" version, which is a version number that is independent of the actual server version in order to assist with migration of Oracle databases, and may be configured within the Oracle server itself. This compatibility version is retrieved using the query ``SELECT value FROM v$parameter WHERE name = 'compatible';``. The SQLAlchemy Oracle dialect, when tasked with determining the default max identifier length, will attempt to use this query upon first connect in order to determine the effective compatibility version of the server, which determines what the maximum allowed identifier length is for the server. If the table is not available, the server version information is used instead. For the duration of the SQLAlchemy 1.3 series, the default max identifier length will remain at 30, even if compatibility version 12.2 or greater is in use. When the newer version is detected, a warning will be emitted upon first connect, which refers the user to make use of the :paramref:`_sa.create_engine.max_identifier_length` parameter in order to assure forwards compatibility with SQLAlchemy 1.4, which will be changing this value to 128 when compatibility version 12.2 or greater is detected. Using :paramref:`_sa.create_engine.max_identifier_length`, the effective identifier length used by the SQLAlchemy dialect will be used as given, overriding the current default value of 30, so that when Oracle 12.2 or greater is used, the newer identifier length may be taken advantage of:: engine = create_engine( "oracle+cx_oracle://scott:tiger@oracle122", max_identifier_length=128) The maximum identifier length comes into play both when generating anonymized SQL labels in SELECT statements, but more crucially when generating constraint names from a naming convention. It is this area that has created the need for SQLAlchemy to change this default conservatively. For example, the following naming convention produces two very different constraint names based on the identifier length:: from sqlalchemy import Column from sqlalchemy import Index from sqlalchemy import Integer from sqlalchemy import MetaData from sqlalchemy import Table from sqlalchemy.dialects import oracle from sqlalchemy.schema import CreateIndex m = MetaData(naming_convention={"ix": "ix_%(column_0N_name)s"}) t = Table( "t", m, Column("some_column_name_1", Integer), Column("some_column_name_2", Integer), Column("some_column_name_3", Integer), ) ix = Index( None, t.c.some_column_name_1, t.c.some_column_name_2, t.c.some_column_name_3, ) oracle_dialect = oracle.dialect(max_identifier_length=30) print(CreateIndex(ix).compile(dialect=oracle_dialect)) With an identifier length of 30, the above CREATE INDEX looks like:: CREATE INDEX ix_some_column_name_1s_70cd ON t (some_column_name_1, some_column_name_2, some_column_name_3) However with length=128, it becomes:: CREATE INDEX ix_some_column_name_1some_column_name_2some_column_name_3 ON t (some_column_name_1, some_column_name_2, some_column_name_3) The implication here is that by upgrading SQLAlchemy to version 1.4 on an existing Oracle 12.2 or greater database, the generation of constraint names will change, which can impact the behavior of database migrations. A key example is a migration that wishes to "DROP CONSTRAINT" on a name that was previously generated with the shorter length. This migration will fail when the identifier length is changed without the name of the index or constraint first being adjusted. Therefore, applications are strongly advised to make use of :paramref:`_sa.create_engine.max_identifier_length` in order to maintain control of the generation of truncated names, and to fully review and test all database migrations in a staging environment when changing this value to ensure that the impact of this change has been mitigated. .. versionadded:: 1.3.9 Added the :paramref:`_sa.create_engine.max_identifier_length` parameter; the Oracle dialect now detects compatibility version 12.2 or greater and warns about upcoming max identitifier length changes in SQLAlchemy 1.4. LIMIT/OFFSET Support -------------------- Oracle has no support for the LIMIT or OFFSET keywords. SQLAlchemy uses a wrapped subquery approach in conjunction with ROWNUM. The exact methodology is taken from http://www.oracle.com/technetwork/issue-archive/2006/06-sep/o56asktom-086197.html . There are two options which affect its behavior: * the "FIRST ROWS()" optimization keyword is not used by default. To enable the usage of this optimization directive, specify ``optimize_limits=True`` to :func:`_sa.create_engine`. * the values passed for the limit/offset are sent as bound parameters. Some users have observed that Oracle produces a poor query plan when the values are sent as binds and not rendered literally. To render the limit/offset values literally within the SQL statement, specify ``use_binds_for_limits=False`` to :func:`_sa.create_engine`. Some users have reported better performance when the entirely different approach of a window query is used, i.e. ROW_NUMBER() OVER (ORDER BY), to provide LIMIT/OFFSET (note that the majority of users don't observe this). To suit this case the method used for LIMIT/OFFSET can be replaced entirely. See the recipe at http://www.sqlalchemy.org/trac/wiki/UsageRecipes/WindowFunctionsByDefault which installs a select compiler that overrides the generation of limit/offset with a window function. .. _oracle_returning: RETURNING Support ----------------- The Oracle database supports a limited form of RETURNING, in order to retrieve result sets of matched rows from INSERT, UPDATE and DELETE statements. Oracle's RETURNING..INTO syntax only supports one row being returned, as it relies upon OUT parameters in order to function. In addition, supported DBAPIs have further limitations (see :ref:`cx_oracle_returning`). SQLAlchemy's "implicit returning" feature, which employs RETURNING within an INSERT and sometimes an UPDATE statement in order to fetch newly generated primary key values and other SQL defaults and expressions, is normally enabled on the Oracle backend. By default, "implicit returning" typically only fetches the value of a single ``nextval(some_seq)`` expression embedded into an INSERT in order to increment a sequence within an INSERT statement and get the value back at the same time. To disable this feature across the board, specify ``implicit_returning=False`` to :func:`_sa.create_engine`:: engine = create_engine("oracle://scott:tiger@dsn", implicit_returning=False) Implicit returning can also be disabled on a table-by-table basis as a table option:: # Core Table my_table = Table("my_table", metadata, ..., implicit_returning=False) # declarative class MyClass(Base): __tablename__ = 'my_table' __table_args__ = {"implicit_returning": False} .. seealso:: :ref:`cx_oracle_returning` - additional cx_oracle-specific restrictions on implicit returning. ON UPDATE CASCADE ----------------- Oracle doesn't have native ON UPDATE CASCADE functionality. A trigger based solution is available at http://asktom.oracle.com/tkyte/update_cascade/index.html . When using the SQLAlchemy ORM, the ORM has limited ability to manually issue cascading updates - specify ForeignKey objects using the "deferrable=True, initially='deferred'" keyword arguments, and specify "passive_updates=False" on each relationship(). Oracle 8 Compatibility ---------------------- When Oracle 8 is detected, the dialect internally configures itself to the following behaviors: * the use_ansi flag is set to False. This has the effect of converting all JOIN phrases into the WHERE clause, and in the case of LEFT OUTER JOIN makes use of Oracle's (+) operator. * the NVARCHAR2 and NCLOB datatypes are no longer generated as DDL when the :class:`~sqlalchemy.types.Unicode` is used - VARCHAR2 and CLOB are issued instead. This because these types don't seem to work correctly on Oracle 8 even though they are available. The :class:`~sqlalchemy.types.NVARCHAR` and :class:`~sqlalchemy.dialects.oracle.NCLOB` types will always generate NVARCHAR2 and NCLOB. * the "native unicode" mode is disabled when using cx_oracle, i.e. SQLAlchemy encodes all Python unicode objects to "string" before passing in as bind parameters. Synonym/DBLINK Reflection ------------------------- When using reflection with Table objects, the dialect can optionally search for tables indicated by synonyms, either in local or remote schemas or accessed over DBLINK, by passing the flag ``oracle_resolve_synonyms=True`` as a keyword argument to the :class:`_schema.Table` construct:: some_table = Table('some_table', autoload=True, autoload_with=some_engine, oracle_resolve_synonyms=True) When this flag is set, the given name (such as ``some_table`` above) will be searched not just in the ``ALL_TABLES`` view, but also within the ``ALL_SYNONYMS`` view to see if this name is actually a synonym to another name. If the synonym is located and refers to a DBLINK, the oracle dialect knows how to locate the table's information using DBLINK syntax(e.g. ``@dblink``). ``oracle_resolve_synonyms`` is accepted wherever reflection arguments are accepted, including methods such as :meth:`_schema.MetaData.reflect` and :meth:`_reflection.Inspector.get_columns`. If synonyms are not in use, this flag should be left disabled. .. _oracle_constraint_reflection: Constraint Reflection --------------------- The Oracle dialect can return information about foreign key, unique, and CHECK constraints, as well as indexes on tables. Raw information regarding these constraints can be acquired using :meth:`_reflection.Inspector.get_foreign_keys`, :meth:`_reflection.Inspector.get_unique_constraints`, :meth:`_reflection.Inspector.get_check_constraints`, and :meth:`_reflection.Inspector.get_indexes`. .. versionchanged:: 1.2 The Oracle dialect can now reflect UNIQUE and CHECK constraints. When using reflection at the :class:`_schema.Table` level, the :class:`_schema.Table` will also include these constraints. Note the following caveats: * When using the :meth:`_reflection.Inspector.get_check_constraints` method, Oracle builds a special "IS NOT NULL" constraint for columns that specify "NOT NULL". This constraint is not returned by default; to include the "IS NOT NULL" constraints, pass the flag ``include_all=True``:: from sqlalchemy import create_engine, inspect engine = create_engine("oracle+cx_oracle://s:t@dsn") inspector = inspect(engine) all_check_constraints = inspector.get_check_constraints( "some_table", include_all=True) * in most cases, when reflecting a :class:`_schema.Table`, a UNIQUE constraint will not be available as a :class:`.UniqueConstraint` object, as Oracle mirrors unique constraints with a UNIQUE index in most cases (the exception seems to be when two or more unique constraints represent the same columns); the :class:`_schema.Table` will instead represent these using :class:`.Index` with the ``unique=True`` flag set. * Oracle creates an implicit index for the primary key of a table; this index is excluded from all index results. * the list of columns reflected for an index will not include column names that start with SYS_NC. Table names with SYSTEM/SYSAUX tablespaces ------------------------------------------- The :meth:`_reflection.Inspector.get_table_names` and :meth:`_reflection.Inspector.get_temp_table_names` methods each return a list of table names for the current engine. These methods are also part of the reflection which occurs within an operation such as :meth:`_schema.MetaData.reflect`. By default, these operations exclude the ``SYSTEM`` and ``SYSAUX`` tablespaces from the operation. In order to change this, the default list of tablespaces excluded can be changed at the engine level using the ``exclude_tablespaces`` parameter:: # exclude SYSAUX and SOME_TABLESPACE, but not SYSTEM e = create_engine( "oracle://scott:tiger@xe", exclude_tablespaces=["SYSAUX", "SOME_TABLESPACE"]) .. versionadded:: 1.1 DateTime Compatibility ---------------------- Oracle has no datatype known as ``DATETIME``, it instead has only ``DATE``, which can actually store a date and time value. For this reason, the Oracle dialect provides a type :class:`_oracle.DATE` which is a subclass of :class:`.DateTime`. This type has no special behavior, and is only present as a "marker" for this type; additionally, when a database column is reflected and the type is reported as ``DATE``, the time-supporting :class:`_oracle.DATE` type is used. .. versionchanged:: 0.9.4 Added :class:`_oracle.DATE` to subclass :class:`.DateTime`. This is a change as previous versions would reflect a ``DATE`` column as :class:`_types.DATE`, which subclasses :class:`.Date`. The only significance here is for schemes that are examining the type of column for use in special Python translations or for migrating schemas to other database backends. .. _oracle_table_options: Oracle Table Options ------------------------- The CREATE TABLE phrase supports the following options with Oracle in conjunction with the :class:`_schema.Table` construct: * ``ON COMMIT``:: Table( "some_table", metadata, ..., prefixes=['GLOBAL TEMPORARY'], oracle_on_commit='PRESERVE ROWS') .. versionadded:: 1.0.0 * ``COMPRESS``:: Table('mytable', metadata, Column('data', String(32)), oracle_compress=True) Table('mytable', metadata, Column('data', String(32)), oracle_compress=6) The ``oracle_compress`` parameter accepts either an integer compression level, or ``True`` to use the default compression level. .. versionadded:: 1.0.0 .. _oracle_index_options: Oracle Specific Index Options ----------------------------- Bitmap Indexes ~~~~~~~~~~~~~~ You can specify the ``oracle_bitmap`` parameter to create a bitmap index instead of a B-tree index:: Index('my_index', my_table.c.data, oracle_bitmap=True) Bitmap indexes cannot be unique and cannot be compressed. SQLAlchemy will not check for such limitations, only the database will. .. versionadded:: 1.0.0 Index compression ~~~~~~~~~~~~~~~~~ Oracle has a more efficient storage mode for indexes containing lots of repeated values. Use the ``oracle_compress`` parameter to turn on key compression:: Index('my_index', my_table.c.data, oracle_compress=True) Index('my_index', my_table.c.data1, my_table.c.data2, unique=True, oracle_compress=1) The ``oracle_compress`` parameter accepts either an integer specifying the number of prefix columns to compress, or ``True`` to use the default (all columns for non-unique indexes, all but the last column for unique indexes). .. versionadded:: 1.0.0 """ # noqa from itertools import groupby import re from ... import Computed from ... import exc from ... import schema as sa_schema from ... import sql from ... import types as sqltypes from ... import util from ...engine import default from ...engine import reflection from ...sql import compiler from ...sql import expression from ...sql import util as sql_util from ...sql import visitors from ...types import BLOB from ...types import CHAR from ...types import CLOB from ...types import FLOAT from ...types import INTEGER from ...types import NCHAR from ...types import NVARCHAR from ...types import TIMESTAMP from ...types import VARCHAR RESERVED_WORDS = set( "SHARE RAW DROP BETWEEN FROM DESC OPTION PRIOR LONG THEN " "DEFAULT ALTER IS INTO MINUS INTEGER NUMBER GRANT IDENTIFIED " "ALL TO ORDER ON FLOAT DATE HAVING CLUSTER NOWAIT RESOURCE " "ANY TABLE INDEX FOR UPDATE WHERE CHECK SMALLINT WITH DELETE " "BY ASC REVOKE LIKE SIZE RENAME NOCOMPRESS NULL GROUP VALUES " "AS IN VIEW EXCLUSIVE COMPRESS SYNONYM SELECT INSERT EXISTS " "NOT TRIGGER ELSE CREATE INTERSECT PCTFREE DISTINCT USER " "CONNECT SET MODE OF UNIQUE VARCHAR2 VARCHAR LOCK OR CHAR " "DECIMAL UNION PUBLIC AND START UID COMMENT CURRENT LEVEL".split() ) NO_ARG_FNS = set( "UID CURRENT_DATE SYSDATE USER " "CURRENT_TIME CURRENT_TIMESTAMP".split() ) class RAW(sqltypes._Binary): __visit_name__ = "RAW" OracleRaw = RAW class NCLOB(sqltypes.Text): __visit_name__ = "NCLOB" class VARCHAR2(VARCHAR): __visit_name__ = "VARCHAR2" NVARCHAR2 = NVARCHAR class NUMBER(sqltypes.Numeric, sqltypes.Integer): __visit_name__ = "NUMBER" def __init__(self, precision=None, scale=None, asdecimal=None): if asdecimal is None: asdecimal = bool(scale and scale > 0) super(NUMBER, self).__init__( precision=precision, scale=scale, asdecimal=asdecimal ) def adapt(self, impltype): ret = super(NUMBER, self).adapt(impltype) # leave a hint for the DBAPI handler ret._is_oracle_number = True return ret @property def _type_affinity(self): if bool(self.scale and self.scale > 0): return sqltypes.Numeric else: return sqltypes.Integer class DOUBLE_PRECISION(sqltypes.Float): __visit_name__ = "DOUBLE_PRECISION" class BINARY_DOUBLE(sqltypes.Float): __visit_name__ = "BINARY_DOUBLE" class BINARY_FLOAT(sqltypes.Float): __visit_name__ = "BINARY_FLOAT" class BFILE(sqltypes.LargeBinary): __visit_name__ = "BFILE" class LONG(sqltypes.Text): __visit_name__ = "LONG" class DATE(sqltypes.DateTime): """Provide the oracle DATE type. This type has no special Python behavior, except that it subclasses :class:`_types.DateTime`; this is to suit the fact that the Oracle ``DATE`` type supports a time value. .. versionadded:: 0.9.4 """ __visit_name__ = "DATE" def _compare_type_affinity(self, other): return other._type_affinity in (sqltypes.DateTime, sqltypes.Date) class INTERVAL(sqltypes.TypeEngine): __visit_name__ = "INTERVAL" def __init__(self, day_precision=None, second_precision=None): """Construct an INTERVAL. Note that only DAY TO SECOND intervals are currently supported. This is due to a lack of support for YEAR TO MONTH intervals within available DBAPIs (cx_oracle and zxjdbc). :param day_precision: the day precision value. this is the number of digits to store for the day field. Defaults to "2" :param second_precision: the second precision value. this is the number of digits to store for the fractional seconds field. Defaults to "6". """ self.day_precision = day_precision self.second_precision = second_precision @classmethod def _adapt_from_generic_interval(cls, interval): return INTERVAL( day_precision=interval.day_precision, second_precision=interval.second_precision, ) @property def _type_affinity(self): return sqltypes.Interval class ROWID(sqltypes.TypeEngine): """Oracle ROWID type. When used in a cast() or similar, generates ROWID. """ __visit_name__ = "ROWID" class _OracleBoolean(sqltypes.Boolean): def get_dbapi_type(self, dbapi): return dbapi.NUMBER colspecs = { sqltypes.Boolean: _OracleBoolean, sqltypes.Interval: INTERVAL, sqltypes.DateTime: DATE, } ischema_names = { "VARCHAR2": VARCHAR, "NVARCHAR2": NVARCHAR, "CHAR": CHAR, "NCHAR": NCHAR, "DATE": DATE, "NUMBER": NUMBER, "BLOB": BLOB, "BFILE": BFILE, "CLOB": CLOB, "NCLOB": NCLOB, "TIMESTAMP": TIMESTAMP, "TIMESTAMP WITH TIME ZONE": TIMESTAMP, "INTERVAL DAY TO SECOND": INTERVAL, "RAW": RAW, "FLOAT": FLOAT, "DOUBLE PRECISION": DOUBLE_PRECISION, "LONG": LONG, "BINARY_DOUBLE": BINARY_DOUBLE, "BINARY_FLOAT": BINARY_FLOAT, } class OracleTypeCompiler(compiler.GenericTypeCompiler): # Note: # Oracle DATE == DATETIME # Oracle does not allow milliseconds in DATE # Oracle does not support TIME columns def visit_datetime(self, type_, kw): return self.visit_DATE(type_, kw) def visit_float(self, type_, kw): return self.visit_FLOAT(type_, kw) def visit_unicode(self, type_, kw): if self.dialect._use_nchar_for_unicode: return self.visit_NVARCHAR2(type_, kw) else: return self.visit_VARCHAR2(type_, kw) def visit_INTERVAL(self, type_, kw): return "INTERVAL DAY%s TO SECOND%s" % ( type_.day_precision is not None and "(%d)" % type_.day_precision or "", type_.second_precision is not None and "(%d)" % type_.second_precision or "", ) def visit_LONG(self, type_, kw): return "LONG" def visit_TIMESTAMP(self, type_, kw): if type_.timezone: return "TIMESTAMP WITH TIME ZONE" else: return "TIMESTAMP" def visit_DOUBLE_PRECISION(self, type_, kw): return self._generate_numeric(type_, "DOUBLE PRECISION", kw) def visit_BINARY_DOUBLE(self, type_, kw): return self._generate_numeric(type_, "BINARY_DOUBLE", kw) def visit_BINARY_FLOAT(self, type_, kw): return self._generate_numeric(type_, "BINARY_FLOAT", kw) def visit_FLOAT(self, type_, kw): # don't support conversion between decimal/binary # precision yet kw["no_precision"] = True return self._generate_numeric(type_, "FLOAT", kw) def visit_NUMBER(self, type_, kw): return self._generate_numeric(type_, "NUMBER", kw) def _generate_numeric( self, type_, name, precision=None, scale=None, no_precision=False, kw ): if precision is None: precision = type_.precision if scale is None: scale = getattr(type_, "scale", None) if no_precision or precision is None: return name elif scale is None: n = "%(name)s(%(precision)s)" return n % {"name": name, "precision": precision} else: n = "%(name)s(%(precision)s, %(scale)s)" return n % {"name": name, "precision": precision, "scale": scale} def visit_string(self, type_, kw): return self.visit_VARCHAR2(type_, kw) def visit_VARCHAR2(self, type_, kw): return self._visit_varchar(type_, "", "2") def visit_NVARCHAR2(self, type_, kw): return self._visit_varchar(type_, "N", "2") visit_NVARCHAR = visit_NVARCHAR2 def visit_VARCHAR(self, type_, kw): return self._visit_varchar(type_, "", "") def _visit_varchar(self, type_, n, num): if not type_.length: return "%(n)sVARCHAR%(two)s" % {"two": num, "n": n} elif not n and self.dialect._supports_char_length: varchar = "VARCHAR%(two)s(%(length)s CHAR)" return varchar % {"length": type_.length, "two": num} else: varchar = "%(n)sVARCHAR%(two)s(%(length)s)" return varchar % {"length": type_.length, "two": num, "n": n} def visit_text(self, type_, kw): return self.visit_CLOB(type_, kw) def visit_unicode_text(self, type_, kw): if self.dialect._use_nchar_for_unicode: return self.visit_NCLOB(type_, kw) else: return self.visit_CLOB(type_, kw) def visit_large_binary(self, type_, kw): return self.visit_BLOB(type_, kw) def visit_big_integer(self, type_, kw): return self.visit_NUMBER(type_, precision=19, kw) def visit_boolean(self, type_, kw): return self.visit_SMALLINT(type_, kw) def visit_RAW(self, type_, kw): if type_.length: return "RAW(%(length)s)" % {"length": type_.length} else: return "RAW" def visit_ROWID(self, type_, *kw): return "ROWID" class OracleCompiler(compiler.SQLCompiler): """Oracle compiler modifies the lexical structure of Select statements to work under non-ANSI configured Oracle databases, if the use_ansi flag is False. """ compound_keywords = util.update_copy( compiler.SQLCompiler.compound_keywords, {expression.CompoundSelect.EXCEPT: "MINUS"}, ) def __init__(self, args, *kwargs): self.__wheres = {} self._quoted_bind_names = {} super(OracleCompiler, self).__init__(args, kwargs) def visit_mod_binary(self, binary, operator, kw): return "mod(%s, %s)" % ( self.process(binary.left, kw), self.process(binary.right, kw), ) def visit_now_func(self, fn, kw): return "CURRENT_TIMESTAMP" def visit_char_length_func(self, fn, kw): return "LENGTH" + self.function_argspec(fn, kw) def visit_match_op_binary(self, binary, operator, kw): return "CONTAINS (%s, %s)" % ( self.process(binary.left), self.process(binary.right), ) def visit_true(self, expr, kw): return "1" def visit_false(self, expr, kw): return "0" def get_cte_preamble(self, recursive): return "WITH" def get_select_hint_text(self, byfroms): return " ".join("/+ %s /" % text for table, text in byfroms.items()) def function_argspec(self, fn, kw): if len(fn.clauses) > 0 or fn.name.upper() not in NO_ARG_FNS: return compiler.SQLCompiler.function_argspec(self, fn, kw) else: return "" def default_from(self): """Called when a ``SELECT`` statement has no froms, and no ``FROM`` clause is to be appended. The Oracle compiler tacks a "FROM DUAL" to the statement. """ return " FROM DUAL" def visit_join(self, join, kwargs): if self.dialect.use_ansi: return compiler.SQLCompiler.visit_join(self, join, kwargs) else: kwargs["asfrom"] = True if isinstance(join.right, expression.FromGrouping): right = join.right.element else: right = join.right return ( self.process(join.left, kwargs) + ", " + self.process(right, kwargs) ) def _get_nonansi_join_whereclause(self, froms): clauses = [] def visit_join(join): if join.isouter: # https://docs.oracle.com/database/121/SQLRF/queries006.htm#SQLRF52354 # "apply the outer join operator (+) to all columns of B in # the join condition in the WHERE clause" - that is, # unconditionally regardless of operator or the other side def visit_binary(binary): if isinstance( binary.left, expression.ColumnClause ) and join.right.is_derived_from(binary.left.table): binary.left = _OuterJoinColumn(binary.left) elif isinstance( binary.right, expression.ColumnClause ) and join.right.is_derived_from(binary.right.table): binary.right = _OuterJoinColumn(binary.right) clauses.append( visitors.cloned_traverse( join.onclause, {}, {"binary": visit_binary} ) ) else: clauses.append(join.onclause) for j in join.left, join.right: if isinstance(j, expression.Join): visit_join(j) elif isinstance(j, expression.FromGrouping): visit_join(j.element) for f in froms: if isinstance(f, expression.Join): visit_join(f) if not clauses: return None else: return sql.and_(clauses) def visit_outer_join_column(self, vc, kw): return self.process(vc.column, kw) + "(+)" def visit_sequence(self, seq, kw): return self.preparer.format_sequence(seq) + ".nextval" def get_render_as_alias_suffix(self, alias_name_text): """Oracle doesn't like ``FROM table AS alias``""" return " " + alias_name_text def returning_clause(self, stmt, returning_cols): columns = [] binds = [] for i, column in enumerate( expression._select_iterables(returning_cols) ): if ( self.isupdate and isinstance(column, sa_schema.Column) and isinstance(column.server_default, Computed) and not self.dialect._supports_update_returning_computed_cols ): util.warn( "Computed columns don't work with Oracle UPDATE " "statements that use RETURNING; the value of the column " "before* the UPDATE takes place is returned. It is " "advised to not use RETURNING with an Oracle computed " "column. Consider setting implicit_returning to False on " "the Table object in order to avoid implicit RETURNING " "clauses from being generated for this Table." ) if column.type._has_column_expression: col_expr = column.type.column_expression(column) else: col_expr = column outparam = sql.outparam("ret_%d" % i, type_=column.type) self.binds[outparam.key] = outparam binds.append( self.bindparam_string(self._truncate_bindparam(outparam)) ) columns.append(self.process(col_expr, within_columns_clause=False)) self._add_to_result_map( getattr(col_expr, "name", col_expr.anon_label), getattr(col_expr, "name", col_expr.anon_label), ( column, getattr(column, "name", None), getattr(column, "key", None), ), column.type, ) return "RETURNING " + ", ".join(columns) + " INTO " + ", ".join(binds) def _TODO_visit_compound_select(self, select): """Need to determine how to get ``LIMIT``/``OFFSET`` into a ``UNION`` for Oracle. """ pass def visit_select(self, select, *kwargs): """Look for ``LIMIT`` and OFFSET in a select statement, and if so tries to wrap it in a subquery with ``rownum`` criterion. """ if not getattr(select, "_oracle_visit", None): if not self.dialect.use_ansi: froms = self._display_froms_for_select( select, kwargs.get("asfrom", False) ) whereclause = self._get_nonansi_join_whereclause(froms) if whereclause is not None: select = select.where(whereclause) select._oracle_visit = True limit_clause = select._limit_clause offset_clause = select._offset_clause if limit_clause is not None or offset_clause is not None: # See http://www.oracle.com/technology/oramag/oracle/06-sep/\ # o56asktom.html # # Generalized form of an Oracle pagination query: # select ... from ( # select /+ FIRST_ROWS(N) / ...., rownum as ora_rn from # ( select distinct ... where ... order by ... # ) where ROWNUM <= :limit+:offset # ) where ora_rn > :offset # Outer select and "ROWNUM as ora_rn" can be dropped if # limit=0 kwargs["select_wraps_for"] = select select = select._generate() select._oracle_visit = True # Wrap the middle select and add the hint limitselect = sql.select([c for c in select.c]) if ( limit_clause is not None and self.dialect.optimize_limits and select._simple_int_limit ): limitselect = limitselect.prefix_with( "/+ FIRST_ROWS(%d) /" % select._limit ) limitselect._oracle_visit = True limitselect._is_wrapper = True # add expressions to accommodate FOR UPDATE OF for_update = select._for_update_arg if for_update is not None and for_update.of: for_update = for_update._clone() for_update._copy_internals() for elem in for_update.of: select.append_column(elem) adapter = sql_util.ClauseAdapter(select) for_update.of = [ adapter.traverse(elem) for elem in for_update.of ] # If needed, add the limiting clause if limit_clause is not None: if not self.dialect.use_binds_for_limits: # use simple int limits, will raise an exception # if the limit isn't specified this way max_row = select._limit if offset_clause is not None: max_row += select._offset max_row = sql.literal_column("%d" % max_row) else: max_row = limit_clause if offset_clause is not None: max_row = max_row + offset_clause limitselect.append_whereclause( sql.literal_column("ROWNUM") <= max_row ) # If needed, add the ora_rn, and wrap again with offset. if offset_clause is None: limitselect._for_update_arg = for_update select = limitselect else: limitselect = limitselect.column( sql.literal_column("ROWNUM").label("ora_rn") ) limitselect._oracle_visit = True limitselect._is_wrapper = True offsetselect = sql.select( [c for c in limitselect.c if c.key != "ora_rn"] ) offsetselect._oracle_visit = True offsetselect._is_wrapper = True if for_update is not None and for_update.of: for elem in for_update.of: if limitselect.corresponding_column(elem) is None: limitselect.append_column(elem) if not self.dialect.use_binds_for_limits: offset_clause = sql.literal_column( "%d" % select._offset ) offsetselect.append_whereclause( sql.literal_column("ora_rn") > offset_clause ) offsetselect._for_update_arg = for_update select = offsetselect return compiler.SQLCompiler.visit_select(self, select, kwargs) def limit_clause(self, select, kw): return "" def visit_empty_set_expr(self, type_): return "SELECT 1 FROM DUAL WHERE 1!=1" def for_update_clause(self, select, kw): if self.is_subquery(): return "" tmp = " FOR UPDATE" if select._for_update_arg.of: tmp += " OF " + ", ".join( self.process(elem, kw) for elem in select._for_update_arg.of ) if select._for_update_arg.nowait: tmp += " NOWAIT" if select._for_update_arg.skip_locked: tmp += " SKIP LOCKED" return tmp def visit_is_distinct_from_binary(self, binary, operator, kw): return "DECODE(%s, %s, 0, 1) = 1" % ( self.process(binary.left), self.process(binary.right), ) def visit_isnot_distinct_from_binary(self, binary, operator, kw): return "DECODE(%s, %s, 0, 1) = 0" % ( self.process(binary.left), self.process(binary.right), ) class OracleDDLCompiler(compiler.DDLCompiler): def define_constraint_cascades(self, constraint): text = "" if constraint.ondelete is not None: text += " ON DELETE %s" % constraint.ondelete # oracle has no ON UPDATE CASCADE - # its only available via triggers # http://asktom.oracle.com/tkyte/update_cascade/index.html if constraint.onupdate is not None: util.warn( "Oracle does not contain native UPDATE CASCADE " "functionality - onupdates will not be rendered for foreign " "keys. Consider using deferrable=True, initially='deferred' " "or triggers." ) return text def visit_drop_table_comment(self, drop): return "COMMENT ON TABLE %s IS ''" % self.preparer.format_table( drop.element ) def visit_create_index(self, create): index = create.element self._verify_index_table(index) preparer = self.preparer text = "CREATE " if index.unique: text += "UNIQUE " if index.dialect_options["oracle"]["bitmap"]: text += "BITMAP " text += "INDEX %s ON %s (%s)" % ( self._prepared_index_name(index, include_schema=True), preparer.format_table(index.table, use_schema=True), ", ".join( self.sql_compiler.process( expr, include_table=False, literal_binds=True ) for expr in index.expressions ), ) if index.dialect_options["oracle"]["compress"] is not False: if index.dialect_options["oracle"]["compress"] is True: text += " COMPRESS" else: text += " COMPRESS %d" % ( index.dialect_options["oracle"]["compress"] ) return text def post_create_table(self, table): table_opts = [] opts = table.dialect_options["oracle"] if opts["on_commit"]: on_commit_options = opts["on_commit"].replace("_", " ").upper() table_opts.append("\n ON COMMIT %s" % on_commit_options) if opts["compress"]: if opts["compress"] is True: table_opts.append("\n COMPRESS") else: table_opts.append("\n COMPRESS FOR %s" % (opts["compress"])) return "".join(table_opts) def visit_computed_column(self, generated): text = "GENERATED ALWAYS AS (%s)" % self.sql_compiler.process( generated.sqltext, include_table=False, literal_binds=True ) if generated.persisted is True: raise exc.CompileError( "Oracle computed columns do not support 'stored' persistence; " "set the 'persisted' flag to None or False for Oracle support." ) elif generated.persisted is False: text += " VIRTUAL" return text class OracleIdentifierPreparer(compiler.IdentifierPreparer): reserved_words = {x.lower() for x in RESERVED_WORDS} illegal_initial_characters = {str(dig) for dig in range(0, 10)}.union( ["_", "$"] ) def _bindparam_requires_quotes(self, value): """Return True if the given identifier requires quoting.""" lc_value = value.lower() return ( lc_value in self.reserved_words or value[0] in self.illegal_initial_characters or not self.legal_characters.match(util.text_type(value)) ) def format_savepoint(self, savepoint): name = savepoint.ident.lstrip("_") return super(OracleIdentifierPreparer, self).format_savepoint( savepoint, name ) class OracleExecutionContext(default.DefaultExecutionContext): def fire_sequence(self, seq, type_): return self._execute_scalar( "SELECT " + self.identifier_preparer.format_sequence(seq) + ".nextval FROM DUAL", type_, ) class OracleDialect(default.DefaultDialect): name = "oracle" supports_alter = True supports_unicode_statements = False supports_unicode_binds = False max_identifier_length = 30 supports_simple_order_by_label = False cte_follows_insert = True supports_sequences = True sequences_optional = False postfetch_lastrowid = False default_paramstyle = "named" colspecs = colspecs ischema_names = ischema_names requires_name_normalize = True supports_comments = True supports_default_values = False supports_empty_insert = False statement_compiler = OracleCompiler ddl_compiler = OracleDDLCompiler type_compiler = OracleTypeCompiler preparer = OracleIdentifierPreparer execution_ctx_cls = OracleExecutionContext reflection_options = ("oracle_resolve_synonyms",) _use_nchar_for_unicode = False construct_arguments = [ ( sa_schema.Table, {"resolve_synonyms": False, "on_commit": None, "compress": False}, ), (sa_schema.Index, {"bitmap": False, "compress": False}), ] def __init__( self, use_ansi=True, optimize_limits=False, use_binds_for_limits=True, use_nchar_for_unicode=False, exclude_tablespaces=("SYSTEM", "SYSAUX"), kwargs ): default.DefaultDialect.__init__(self, kwargs) self._use_nchar_for_unicode = use_nchar_for_unicode self.use_ansi = use_ansi self.optimize_limits = optimize_limits self.use_binds_for_limits = use_binds_for_limits self.exclude_tablespaces = exclude_tablespaces def initialize(self, connection): super(OracleDialect, self).initialize(connection) self.implicit_returning = self.__dict__.get( "implicit_returning", self.server_version_info > (10,) ) if self._is_oracle_8: self.colspecs = self.colspecs.copy() self.colspecs.pop(sqltypes.Interval) self.use_ansi = False def _get_effective_compat_server_version_info(self, connection): # dialect does not need compat levels below 12.2, so don't query # in those cases if self.server_version_info < (12, 2): return self.server_version_info try: compat = connection.execute( "SELECT value FROM v$parameter WHERE name = 'compatible'" ).scalar() except exc.DBAPIError: compat = None if compat: try: return tuple(int(x) for x in compat.split(".")) except: return self.server_version_info else: return self.server_version_info @property def _is_oracle_8(self): return self.server_version_info and self.server_version_info < (9,) @property def _supports_table_compression(self): return self.server_version_info and self.server_version_info >= (10, 1) @property def _supports_table_compress_for(self): return self.server_version_info and self.server_version_info >= (11,) @property def _supports_char_length(self): return not self._is_oracle_8 @property def _supports_update_returning_computed_cols(self): # on version 18 this error is no longet present while it happens on 11 # it may work also on versions before the 18 return self.server_version_info and self.server_version_info >= (18,) def do_release_savepoint(self, connection, name): # Oracle does not support RELEASE SAVEPOINT pass def _check_max_identifier_length(self, connection): if self._get_effective_compat_server_version_info(connection) >= ( 12, 2, ): util.warn( "Oracle version %r is known to have a maximum " "identifier length of 128, rather than the historical default " "of 30. SQLAlchemy 1.4 will use 128 for this " "database; please set max_identifier_length=128 " "in create_engine() in order to " "test the application with this new length, or set to 30 in " "order to assure that 30 continues to be used. " "In particular, pay close attention to the behavior of " "database migrations as dynamically generated names may " "change. See the section 'Max Identifier Lengths' in the " "SQLAlchemy Oracle dialect documentation for background." % ((self.server_version_info,)) ) # use the default return None def _check_unicode_returns(self, connection): additional_tests = [ expression.cast( expression.literal_column("'test nvarchar2 returns'"), sqltypes.NVARCHAR(60), ) ] return super(OracleDialect, self)._check_unicode_returns( connection, additional_tests ) _isolation_lookup = ["READ COMMITTED", "SERIALIZABLE"] def get_isolation_level(self, connection): raise NotImplementedError("implemented by cx_Oracle dialect") def get_default_isolation_level(self, dbapi_conn): try: return self.get_isolation_level(dbapi_conn) except NotImplementedError: raise except: return "READ COMMITTED" def set_isolation_level(self, connection, level): raise NotImplementedError("implemented by cx_Oracle dialect") def has_table(self, connection, table_name, schema=None): if not schema: schema = self.default_schema_name cursor = connection.execute( sql.text( "SELECT table_name FROM all_tables " "WHERE table_name = :name AND owner = :schema_name" ), name=self.denormalize_name(table_name), schema_name=self.denormalize_name(schema), ) return cursor.first() is not None def has_sequence(self, connection, sequence_name, schema=None): if not schema: schema = self.default_schema_name cursor = connection.execute( sql.text( "SELECT sequence_name FROM all_sequences " "WHERE sequence_name = :name AND " "sequence_owner = :schema_name" ), name=self.denormalize_name(sequence_name), schema_name=self.denormalize_name(schema), ) return cursor.first() is not None def _get_default_schema_name(self, connection): return self.normalize_name( connection.execute("SELECT USER FROM DUAL").scalar() ) def _resolve_synonym( self, connection, desired_owner=None, desired_synonym=None, desired_table=None, ): """search for a local synonym matching the given desired owner/name. if desired_owner is None, attempts to locate a distinct owner. returns the actual name, owner, dblink name, and synonym name if found. """ q = ( "SELECT owner, table_owner, table_name, db_link, " "synonym_name FROM all_synonyms WHERE " ) clauses = [] params = {} if desired_synonym: clauses.append("synonym_name = :synonym_name") params["synonym_name"] = desired_synonym if desired_owner: clauses.append("owner = :desired_owner") params["desired_owner"] = desired_owner if desired_table: clauses.append("table_name = :tname") params["tname"] = desired_table q += " AND ".join(clauses) result = connection.execute(sql.text(q), params) if desired_owner: row = result.first() if row: return ( row["table_name"], row["table_owner"], row["db_link"], row["synonym_name"], ) else: return None, None, None, None else: rows = result.fetchall() if len(rows) > 1: raise AssertionError( "There are multiple tables visible to the schema, you " "must specify owner" ) elif len(rows) == 1: row = rows[0] return ( row["table_name"], row["table_owner"], row["db_link"], row["synonym_name"], ) else: return None, None, None, None @reflection.cache def _prepare_reflection_args( self, connection, table_name, schema=None, resolve_synonyms=False, dblink="", kw ): if resolve_synonyms: actual_name, owner, dblink, synonym = self._resolve_synonym( connection, desired_owner=self.denormalize_name(schema), desired_synonym=self.denormalize_name(table_name), ) else: actual_name, owner, dblink, synonym = None, None, None, None if not actual_name: actual_name = self.denormalize_name(table_name) if dblink: # using user_db_links here since all_db_links appears # to have more restricted permissions. # http://docs.oracle.com/cd/B28359_01/server.111/b28310/ds_admin005.htm # will need to hear from more users if we are doing # the right thing here. See [ticket:2619] owner = connection.scalar( sql.text( "SELECT username FROM user_db_links " "WHERE db_link=:link" ), link=dblink, ) dblink = "@" + dblink elif not owner: owner = self.denormalize_name(schema or self.default_schema_name) return (actual_name, owner, dblink or "", synonym) @reflection.cache def get_schema_names(self, connection, kw): s = "SELECT username FROM all_users ORDER BY username" cursor = connection.execute(s) return [self.normalize_name(row[0]) for row in cursor] @reflection.cache def get_table_names(self, connection, schema=None, kw): schema = self.denormalize_name(schema or self.default_schema_name) # note that table_names() isn't loading DBLINKed or synonym'ed tables if schema is None: schema = self.default_schema_name sql_str = "SELECT table_name FROM all_tables WHERE " if self.exclude_tablespaces: sql_str += ( "nvl(tablespace_name, 'no tablespace') " "NOT IN (%s) AND " % (", ".join(["'%s'" % ts for ts in self.exclude_tablespaces])) ) sql_str += ( "OWNER = :owner " "AND IOT_NAME IS NULL " "AND DURATION IS NULL" ) cursor = connection.execute(sql.text(sql_str), owner=schema) return [self.normalize_name(row[0]) for row in cursor] @reflection.cache def get_temp_table_names(self, connection, kw): schema = self.denormalize_name(self.default_schema_name) sql_str = "SELECT table_name FROM all_tables WHERE " if self.exclude_tablespaces: sql_str += ( "nvl(tablespace_name, 'no tablespace') " "NOT IN (%s) AND " % (", ".join(["'%s'" % ts for ts in self.exclude_tablespaces])) ) sql_str += ( "OWNER = :owner " "AND IOT_NAME IS NULL " "AND DURATION IS NOT NULL" ) cursor = connection.execute(sql.text(sql_str), owner=schema) return [self.normalize_name(row[0]) for row in cursor] @reflection.cache def get_view_names(self, connection, schema=None, kw): schema = self.denormalize_name(schema or self.default_schema_name) s = sql.text("SELECT view_name FROM all_views WHERE owner = :owner") cursor = connection.execute(s, owner=self.denormalize_name(schema)) return [self.normalize_name(row[0]) for row in cursor] @reflection.cache def get_table_options(self, connection, table_name, schema=None, kw): options = {} resolve_synonyms = kw.get("oracle_resolve_synonyms", False) dblink = kw.get("dblink", "") info_cache = kw.get("info_cache") (table_name, schema, dblink, synonym) = self._prepare_reflection_args( connection, table_name, schema, resolve_synonyms, dblink, info_cache=info_cache, ) params = {"table_name": table_name} columns = ["table_name"] if self._supports_table_compression: columns.append("compression") if self._supports_table_compress_for: columns.append("compress_for") text = ( "SELECT %(columns)s " "FROM ALL_TABLES%(dblink)s " "WHERE table_name = :table_name" ) if schema is not None: params["owner"] = schema text += " AND owner = :owner " text = text % {"dblink": dblink, "columns": ", ".join(columns)} result = connection.execute(sql.text(text), params) enabled = dict(DISABLED=False, ENABLED=True) row = result.first() if row: if "compression" in row and enabled.get(row.compression, False): if "compress_for" in row: options["oracle_compress"] = row.compress_for else: options["oracle_compress"] = True return options @reflection.cache def get_columns(self, connection, table_name, schema=None, kw): """ kw arguments can be: oracle_resolve_synonyms dblink """ resolve_synonyms = kw.get("oracle_resolve_synonyms", False) dblink = kw.get("dblink", "") info_cache = kw.get("info_cache") (table_name, schema, dblink, synonym) = self._prepare_reflection_args( connection, table_name, schema, resolve_synonyms, dblink, info_cache=info_cache, ) columns = [] if self._supports_char_length: char_length_col = "char_length" else: char_length_col = "data_length" params = {"table_name": table_name} text = """ SELECT col.column_name, col.data_type, col.%(char_length_col)s, col.data_precision, col.data_scale, col.nullable, col.data_default, com.comments, col.virtual_column\ FROM all_tab_cols%(dblink)s col LEFT JOIN all_col_comments%(dblink)s com ON col.table_name = com.table_name AND col.column_name = com.column_name AND col.owner = com.owner WHERE col.table_name = :table_name AND col.hidden_column = 'NO' """ if schema is not None: params["owner"] = schema text += " AND col.owner = :owner " text += " ORDER BY col.column_id" text = text % {"dblink": dblink, "char_length_col": char_length_col} c = connection.execute(sql.text(text), params) for row in c: colname = self.normalize_name(row[0]) orig_colname = row[0] coltype = row[1] length = row[2] precision = row[3] scale = row[4] nullable = row[5] == "Y" default = row[6] comment = row[7] generated = row[8] if coltype == "NUMBER": if precision is None and scale == 0: coltype = INTEGER() else: coltype = NUMBER(precision, scale) elif coltype == "FLOAT": # TODO: support "precision" here as "binary_precision" coltype = FLOAT() elif coltype in ("VARCHAR2", "NVARCHAR2", "CHAR", "NCHAR"): coltype = self.ischema_names.get(coltype)(length) elif "WITH TIME ZONE" in coltype: coltype = TIMESTAMP(timezone=True) else: coltype = re.sub(r"\(\d+\)", "", coltype) try: coltype = self.ischema_names[coltype] except KeyError: util.warn( "Did not recognize type '%s' of column '%s'" % (coltype, colname) ) coltype = sqltypes.NULLTYPE if generated == "YES": computed = dict(sqltext=default) default = None else: computed = None cdict = { "name": colname, "type": coltype, "nullable": nullable, "default": default, "autoincrement": "auto", "comment": comment, } if orig_colname.lower() == orig_colname: cdict["quote"] = True if computed is not None: cdict["computed"] = computed columns.append(cdict) return columns @reflection.cache def get_table_comment( self, connection, table_name, schema=None, resolve_synonyms=False, dblink="", kw ): info_cache = kw.get("info_cache") (table_name, schema, dblink, synonym) = self._prepare_reflection_args( connection, table_name, schema, resolve_synonyms, dblink, info_cache=info_cache, ) if not schema: schema = self.default_schema_name COMMENT_SQL = """ SELECT comments FROM all_tab_comments WHERE table_name = :table_name AND owner = :schema_name """ c = connection.execute( sql.text(COMMENT_SQL), table_name=table_name, schema_name=schema ) return {"text": c.scalar()} @reflection.cache def get_indexes( self, connection, table_name, schema=None, resolve_synonyms=False, dblink="", kw ): info_cache = kw.get("info_cache") (table_name, schema, dblink, synonym) = self._prepare_reflection_args( connection, table_name, schema, resolve_synonyms, dblink, info_cache=info_cache, ) indexes = [] params = {"table_name": table_name} text = ( "SELECT a.index_name, a.column_name, " "\nb.index_type, b.uniqueness, b.compression, b.prefix_length " "\nFROM ALL_IND_COLUMNS%(dblink)s a, " "\nALL_INDEXES%(dblink)s b " "\nWHERE " "\na.index_name = b.index_name " "\nAND a.table_owner = b.table_owner " "\nAND a.table_name = b.table_name " "\nAND a.table_name = :table_name " ) if schema is not None: params["schema"] = schema text += "AND a.table_owner = :schema " text += "ORDER BY a.index_name, a.column_position" text = text % {"dblink": dblink} q = sql.text(text) rp = connection.execute(q, params) indexes = [] last_index_name = None pk_constraint = self.get_pk_constraint( connection, table_name, schema, resolve_synonyms=resolve_synonyms, dblink=dblink, info_cache=kw.get("info_cache"), ) uniqueness = dict(NONUNIQUE=False, UNIQUE=True) enabled = dict(DISABLED=False, ENABLED=True) oracle_sys_col = re.compile(r"SYS_NC\d+\$", re.IGNORECASE) index = None for rset in rp: index_name_normalized = self.normalize_name(rset.index_name) # skip primary key index. This is refined as of # [ticket:5421]. Note that ALL_INDEXES.GENERATED will by "Y" # if the name of this index was generated by Oracle, however # if a named primary key constraint was created then this flag # is false. if ( pk_constraint and index_name_normalized == pk_constraint["name"] ): continue if rset.index_name != last_index_name: index = dict( name=index_name_normalized, column_names=[], dialect_options={}, ) indexes.append(index) index["unique"] = uniqueness.get(rset.uniqueness, False) if rset.index_type in ("BITMAP", "FUNCTION-BASED BITMAP"): index["dialect_options"]["oracle_bitmap"] = True if enabled.get(rset.compression, False): index["dialect_options"][ "oracle_compress" ] = rset.prefix_length # filter out Oracle SYS_NC names. could also do an outer join # to the all_tab_columns table and check for real col names there. if not oracle_sys_col.match(rset.column_name): index["column_names"].append( self.normalize_name(rset.column_name) ) last_index_name = rset.index_name return indexes @reflection.cache def _get_constraint_data( self, connection, table_name, schema=None, dblink="", kw ): params = {"table_name": table_name} text = ( "SELECT" "\nac.constraint_name," # 0 "\nac.constraint_type," # 1 "\nloc.column_name AS local_column," # 2 "\nrem.table_name AS remote_table," # 3 "\nrem.column_name AS remote_column," # 4 "\nrem.owner AS remote_owner," # 5 "\nloc.position as loc_pos," # 6 "\nrem.position as rem_pos," # 7 "\nac.search_condition," # 8 "\nac.delete_rule" # 9 "\nFROM all_constraints%(dblink)s ac," "\nall_cons_columns%(dblink)s loc," "\nall_cons_columns%(dblink)s rem" "\nWHERE ac.table_name = :table_name" "\nAND ac.constraint_type IN ('R','P', 'U', 'C')" ) if schema is not None: params["owner"] = schema text += "\nAND ac.owner = :owner" text += ( "\nAND ac.owner = loc.owner" "\nAND ac.constraint_name = loc.constraint_name" "\nAND ac.r_owner = rem.owner(+)" "\nAND ac.r_constraint_name = rem.constraint_name(+)" "\nAND (rem.position IS NULL or loc.position=rem.position)" "\nORDER BY ac.constraint_name, loc.position" ) text = text % {"dblink": dblink} rp = connection.execute(sql.text(text), params) constraint_data = rp.fetchall() return constraint_data @reflection.cache def get_pk_constraint(self, connection, table_name, schema=None, kw): resolve_synonyms = kw.get("oracle_resolve_synonyms", False) dblink = kw.get("dblink", "") info_cache = kw.get("info_cache") (table_name, schema, dblink, synonym) = self._prepare_reflection_args( connection, table_name, schema, resolve_synonyms, dblink, info_cache=info_cache, ) pkeys = [] constraint_name = None constraint_data = self._get_constraint_data( connection, table_name, schema, dblink, info_cache=kw.get("info_cache"), ) for row in constraint_data: ( cons_name, cons_type, local_column, remote_table, remote_column, remote_owner, ) = row[0:2] + tuple([self.normalize_name(x) for x in row[2:6]]) if cons_type == "P": if constraint_name is None: constraint_name = self.normalize_name(cons_name) pkeys.append(local_column) return {"constrained_columns": pkeys, "name": constraint_name} @reflection.cache def get_foreign_keys(self, connection, table_name, schema=None, kw): """ kw arguments can be: oracle_resolve_synonyms dblink """ requested_schema = schema # to check later on resolve_synonyms = kw.get("oracle_resolve_synonyms", False) dblink = kw.get("dblink", "") info_cache = kw.get("info_cache") (table_name, schema, dblink, synonym) = self._prepare_reflection_args( connection, table_name, schema, resolve_synonyms, dblink, info_cache=info_cache, ) constraint_data = self._get_constraint_data( connection, table_name, schema, dblink, info_cache=kw.get("info_cache"), ) def fkey_rec(): return { "name": None, "constrained_columns": [], "referred_schema": None, "referred_table": None, "referred_columns": [], "options": {}, } fkeys = util.defaultdict(fkey_rec) for row in constraint_data: ( cons_name, cons_type, local_column, remote_table, remote_column, remote_owner, ) = row[0:2] + tuple([self.normalize_name(x) for x in row[2:6]]) cons_name = self.normalize_name(cons_name) if cons_type == "R": if remote_table is None: # ticket 363 util.warn( ( "Got 'None' querying 'table_name' from " "all_cons_columns%(dblink)s - does the user have " "proper rights to the table?" ) % {"dblink": dblink} ) continue rec = fkeys[cons_name] rec["name"] = cons_name local_cols, remote_cols = ( rec["constrained_columns"], rec["referred_columns"], ) if not rec["referred_table"]: if resolve_synonyms: ( ref_remote_name, ref_remote_owner, ref_dblink, ref_synonym, ) = self._resolve_synonym( connection, desired_owner=self.denormalize_name(remote_owner), desired_table=self.denormalize_name(remote_table), ) if ref_synonym: remote_table = self.normalize_name(ref_synonym) remote_owner = self.normalize_name( ref_remote_owner ) rec["referred_table"] = remote_table if ( requested_schema is not None or self.denormalize_name(remote_owner) != schema ): rec["referred_schema"] = remote_owner if row[9] != "NO ACTION": rec["options"]["ondelete"] = row[9] local_cols.append(local_column) remote_cols.append(remote_column) return list(fkeys.values()) @reflection.cache def get_unique_constraints( self, connection, table_name, schema=None, kw ): resolve_synonyms = kw.get("oracle_resolve_synonyms", False) dblink = kw.get("dblink", "") info_cache = kw.get("info_cache") (table_name, schema, dblink, synonym) = self._prepare_reflection_args( connection, table_name, schema, resolve_synonyms, dblink, info_cache=info_cache, ) constraint_data = self._get_constraint_data( connection, table_name, schema, dblink, info_cache=kw.get("info_cache"), ) unique_keys = filter(lambda x: x[1] == "U", constraint_data) uniques_group = groupby(unique_keys, lambda x: x[0]) index_names = { ix["name"] for ix in self.get_indexes(connection, table_name, schema=schema) } return [ { "name": name, "column_names": cols, "duplicates_index": name if name in index_names else None, } for name, cols in [ [ self.normalize_name(i[0]), [self.normalize_name(x[2]) for x in i[1]], ] for i in uniques_group ] ] @reflection.cache def get_view_definition( self, connection, view_name, schema=None, resolve_synonyms=False, dblink="", kw ): info_cache = kw.get("info_cache") (view_name, schema, dblink, synonym) = self._prepare_reflection_args( connection, view_name, schema, resolve_synonyms, dblink, info_cache=info_cache, ) params = {"view_name": view_name} text = "SELECT text FROM all_views WHERE view_name=:view_name" if schema is not None: text += " AND owner = :schema" params["schema"] = schema rp = connection.execute(sql.text(text), params).scalar() if rp: if util.py2k: rp = rp.decode(self.encoding) return rp else: return None @reflection.cache def get_check_constraints( self, connection, table_name, schema=None, include_all=False, *kw ): resolve_synonyms = kw.get("oracle_resolve_synonyms", False) dblink = kw.get("dblink", "") info_cache = kw.get("info_cache") (table_name, schema, dblink, synonym) = self._prepare_reflection_args( connection, table_name, schema, resolve_synonyms, dblink, info_cache=info_cache, ) constraint_data = self._get_constraint_data( connection, table_name, schema, dblink, info_cache=kw.get("info_cache"), ) check_constraints = filter(lambda x: x[1] == "C", constraint_data) return [ {"name": self.normalize_name(cons[0]), "sqltext": cons[8]} for cons in check_constraints if include_all or not re.match(r"..+?. IS NOT NULL$", cons[8]) ] class _OuterJoinColumn(sql.ClauseElement): __visit_name__ = "outer_join_column" def __init__(self, column): self.column = column	76.38 KB	2026-01-20 12:58
📄 cx_oracle.py # Copyright (C) 2005-2021 the SQLAlchemy authors and contributors # <see AUTHORS file> # # 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/ DSN vs. Hostname connections ----------------------------- The dialect will connect to a DSN if no database name portion is presented, such as:: engine = create_engine("oracle+cx_oracle://scott:tiger@oracle1120/?encoding=UTF-8&nencoding=UTF-8") Above, ``oracle1120`` is passed to cx_Oracle as an Oracle datasource name. Alternatively, if a database name is present, the ``cx_Oracle.makedsn()`` function is used to create an ad-hoc "datasource" name assuming host and port:: engine = create_engine("oracle+cx_oracle://scott:tiger@hostname:1521/dbname?encoding=UTF-8&nencoding=UTF-8") Above, the DSN would be created 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``. Passing cx_Oracle connect arguments ----------------------------------- Additional connection arguments can usually be passed via the URL query string; particular symbols like ``cx_Oracle.SYSDBA`` are intercepted and converted to the correct symbol:: e = create_engine( "oracle+cx_oracle://user:pass@dsn?encoding=UTF-8&nencoding=UTF-8&mode=SYSDBA&events=true") .. versionchanged:: 1.3 the cx_oracle dialect now accepts all argument names within the URL string itself, to be passed to the cx_Oracle DBAPI. As was the case earlier but not correctly documented, the :paramref:`_sa.create_engine.connect_args` parameter also accepts all cx_Oracle DBAPI connect arguments. To pass arguments directly to ``.connect()`` wihtout using the query string, use the :paramref:`_sa.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={ "encoding": "UTF-8", "nencoding": "UTF-8", "mode": cx_Oracle.SYSDBA, "events": True } ) Options consumed by the SQLAlchemy cx_Oracle dialect outside of the driver -------------------------------------------------------------------------- There are also options that are consumed by the SQLAlchemy cx_oracle dialect itself. These options are always passed directly to :func:`_sa.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. * ``encoding_errors`` - see :ref:`cx_oracle_unicode_encoding_errors` for detail. .. _cx_oracle_unicode: Unicode ------- As is the case for all DBAPIs under Python 3, all strings are inherently Unicode strings. Under Python 2, cx_Oracle also supports Python Unicode objects directly. In all cases however, the driver requires an explicit encoding configuration. Ensuring the Correct Client Encoding ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The long accepted standard for establishing client encoding for nearly all Oracle related software is via the `NLS_LANG <https://www.oracle.com/database/technologies/faq-nls-lang.html>`_ environment variable. cx_Oracle like most other Oracle drivers will use this environment variable as the source of its encoding configuration. The format of this variable is idiosyncratic; a typical value would be ``AMERICAN_AMERICA.AL32UTF8``. The cx_Oracle driver also supports a programmatic alternative which is to pass the ``encoding`` and ``nencoding`` parameters directly to its ``.connect()`` function. These can be present in the URL as follows:: engine = create_engine("oracle+cx_oracle://scott:tiger@oracle1120/?encoding=UTF-8&nencoding=UTF-8") For the meaning of the ``encoding`` and ``nencoding`` parameters, please consult `Characters Sets and National Language Support (NLS) <https://cx-oracle.readthedocs.io/en/latest/user_guide/globalization.html#globalization>`_. .. seealso:: `Characters Sets and National Language Support (NLS) <https://cx-oracle.readthedocs.io/en/latest/user_guide/globalization.html#globalization>`_ - in the cx_Oracle documentation. Unicode-specific Column datatypes ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The Core expression language handles unicode data by use of the :class:`.Unicode` and :class:`.UnicodeText` datatypes. These types correspond to the VARCHAR2 and CLOB Oracle datatypes by default. When using these datatypes with Unicode data, it is expected that the Oracle database is configured with a Unicode-aware character set, as well as that the ``NLS_LANG`` environment variable is set appropriately, so that the VARCHAR2 and CLOB datatypes can accommodate the data. In the case that the Oracle database is not configured with a Unicode character set, the two options are to use the :class:`_types.NCHAR` and :class:`_oracle.NCLOB` datatypes explicitly, or to pass the flag ``use_nchar_for_unicode=True`` to :func:`_sa.create_engine`, which will cause the SQLAlchemy dialect to use NCHAR/NCLOB for the :class:`.Unicode` / :class:`.UnicodeText` datatypes instead of VARCHAR/CLOB. .. versionchanged:: 1.3 The :class:`.Unicode` and :class:`.UnicodeText` datatypes now correspond to the ``VARCHAR2`` and ``CLOB`` Oracle datatypes unless the ``use_nchar_for_unicode=True`` is passed to the dialect when :func:`_sa.create_engine` is called. Unicode Coercion of result rows under Python 2 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ When result sets are fetched that include strings, under Python 3 the cx_Oracle DBAPI returns all strings as Python Unicode objects, since Python 3 only has a Unicode string type. This occurs for data fetched from datatypes such as VARCHAR2, CHAR, CLOB, NCHAR, NCLOB, etc. In order to provide cross- compatibility under Python 2, the SQLAlchemy cx_Oracle dialect will add Unicode-conversion to string data under Python 2 as well. Historically, this made use of converters that were supplied by cx_Oracle but were found to be non-performant; SQLAlchemy's own converters are used for the string to Unicode conversion under Python 2. To disable the Python 2 Unicode conversion for VARCHAR2, CHAR, and CLOB, the flag ``coerce_to_unicode=False`` can be passed to :func:`_sa.create_engine`. .. versionchanged:: 1.3 Unicode conversion is applied to all string values by default under python 2. The ``coerce_to_unicode`` now defaults to True and can be set to False to disable the Unicode coercion of strings that are delivered as VARCHAR2/CHAR/CLOB data. .. _cx_oracle_unicode_encoding_errors: Encoding Errors ^^^^^^^^^^^^^^^ For the unusual case that data in the Oracle database is present with a broken encoding, the dialect accepts a parameter ``encoding_errors`` which will be passed to Unicode decoding functions in order to affect how decoding errors are handled. The value is ultimately consumed by the Python `decode <https://docs.python.org/3/library/stdtypes.html#bytes.decode>`_ function, and is passed both via cx_Oracle's ``encodingErrors`` parameter consumed by ``Cursor.var()``, as well as SQLAlchemy's own decoding function, as the cx_Oracle dialect makes use of both under different circumstances. .. versionadded:: 1.3.11 .. _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#database-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:`_sa.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:`_sa.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 from ...util import compat 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 # TODO: the names used across CHAR / VARCHAR / NCHAR / NVARCHAR # here are inconsistent and not very good class _OracleChar(sqltypes.CHAR): def get_dbapi_type(self, dbapi): return dbapi.FIXED_CHAR class _OracleNChar(sqltypes.NCHAR): def get_dbapi_type(self, dbapi): return dbapi.FIXED_NCHAR class _OracleUnicodeStringNCHAR(oracle.NVARCHAR2): def get_dbapi_type(self, dbapi): return dbapi.NCHAR class _OracleUnicodeStringCHAR(sqltypes.Unicode): def get_dbapi_type(self, dbapi): return dbapi.LONG_STRING class _OracleUnicodeTextNCLOB(oracle.NCLOB): def get_dbapi_type(self, dbapi): return dbapi.NCLOB class _OracleUnicodeTextCLOB(sqltypes.UnicodeText): def get_dbapi_type(self, dbapi): return dbapi.CLOB 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 _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) cx_Oracle = 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) ) if compat.py2k and dbtype in ( cx_Oracle.CLOB, cx_Oracle.NCLOB, ): outconverter = ( processors.to_unicode_processor_factory( self.dialect.encoding, errors=self.dialect.encoding_errors, ) ) self.out_parameters[name] = self.cursor.var( dbtype, outconverter=lambda value: outconverter( value.read() ), ) elif dbtype in ( cx_Oracle.BLOB, cx_Oracle.CLOB, cx_Oracle.NCLOB, ): self.out_parameters[name] = self.cursor.var( dbtype, outconverter=lambda value: value.read() ) elif compat.py2k and isinstance( type_impl, sqltypes.Unicode ): outconverter = ( processors.to_unicode_processor_factory( self.dialect.encoding, errors=self.dialect.encoding_errors, ) ) self.out_parameters[name] = self.cursor.var( dbtype, outconverter=outconverter ) else: 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: _OracleUnicodeTextCLOB, sqltypes.CHAR: _OracleChar, sqltypes.NCHAR: _OracleNChar, sqltypes.Enum: _OracleEnum, oracle.LONG: _OracleLong, oracle.RAW: _OracleRaw, sqltypes.Unicode: _OracleUnicodeStringCHAR, sqltypes.NVARCHAR: _OracleUnicodeStringNCHAR, oracle.NCLOB: _OracleUnicodeTextNCLOB, oracle.ROWID: _OracleRowid, } execute_sequence_format = list _cx_oracle_threaded = None @util.deprecated_params( threaded=( "1.3", "The 'threaded' parameter to the cx_oracle dialect " "is deprecated as a dialect-level argument, and will be removed " "in a future release. As of version 1.3, it defaults to False " "rather than True. The 'threaded' option can be passed to " "cx_Oracle directly in the URL query string passed to " ":func:`_sa.create_engine`.", ) ) def __init__( self, auto_convert_lobs=True, coerce_to_unicode=True, coerce_to_decimal=True, arraysize=50, encoding_errors=None, threaded=None, kwargs ): OracleDialect.__init__(self, kwargs) self.arraysize = arraysize self.encoding_errors = encoding_errors if threaded is not None: self._cx_oracle_threaded = threaded self.auto_convert_lobs = auto_convert_lobs self.coerce_to_unicode = coerce_to_unicode self.coerce_to_decimal = coerce_to_decimal if self._use_nchar_for_unicode: self.colspecs = self.colspecs.copy() self.colspecs[sqltypes.Unicode] = _OracleUnicodeStringNCHAR self.colspecs[sqltypes.UnicodeText] = _OracleUnicodeTextNCLOB 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.DATETIME, 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,) @property def _cursor_var_unicode_kwargs(self): if self.encoding_errors: if self.cx_oracle_ver >= (6, 4): return {"encodingErrors": self.encoding_errors} else: util.warn( "cx_oracle version %r does not support encodingErrors" % (self.cx_oracle_ver,) ) return {} 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 get_isolation_level(self, connection): # sources: # general idea of transaction id, have to start one, etc. # https://stackoverflow.com/questions/10711204/how-to-check-isoloation-level # how to decode xid cols from v$transaction to match # https://asktom.oracle.com/pls/apex/f?p=100:11:0::::P11_QUESTION_ID:9532779900346079444 # Oracle tuple comparison without using IN: # https://www.sql-workbench.eu/comparison/tuple_comparison.html with connection.cursor() as cursor: # this is the only way to ensure a transaction is started without # actually running DML. There's no way to see the configured # isolation level without getting it from v$transaction which # means transaction has to be started. outval = cursor.var(str) cursor.execute( """ begin :trans_id := dbms_transaction.local_transaction_id( TRUE ); end; """, {"trans_id": outval}, ) trans_id = outval.getvalue() xidusn, xidslot, xidsqn = trans_id.split(".", 2) cursor.execute( "SELECT CASE BITAND(t.flag, POWER(2, 28)) " "WHEN 0 THEN 'READ COMMITTED' " "ELSE 'SERIALIZABLE' END AS isolation_level " "FROM v$transaction t WHERE " "(t.xidusn, t.xidslot, t.xidsqn) = " "((:xidusn, :xidslot, :xidsqn))", {"xidusn": xidusn, "xidslot": xidslot, "xidsqn": xidsqn}, ) row = cursor.fetchone() if row is None: raise exc.InvalidRequestError( "could not retrieve isolation level" ) result = row[0] return result def set_isolation_level(self, connection, level): if hasattr(connection, "connection"): dbapi_connection = connection.connection else: dbapi_connection = connection if level == "AUTOCOMMIT": dbapi_connection.autocommit = True else: dbapi_connection.autocommit = False connection.rollback() with connection.cursor() as cursor: cursor.execute("ALTER SESSION SET ISOLATION_LEVEL=%s" % level) 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 and default_type is not cx_Oracle.NATIVE_FLOAT ): 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, ) and default_type is not cx_Oracle.CLOB and default_type is not cx_Oracle.NCLOB ): if compat.py2k: outconverter = processors.to_unicode_processor_factory( dialect.encoding, errors=dialect.encoding_errors ) return cursor.var( cx_Oracle.STRING, size, cursor.arraysize, outconverter=outconverter, ) else: return cursor.var( util.text_type, size, cursor.arraysize, dialect._cursor_var_unicode_kwargs ) elif dialect.auto_convert_lobs and default_type in ( cx_Oracle.CLOB, cx_Oracle.NCLOB, ): if compat.py2k: outconverter = processors.to_unicode_processor_factory( dialect.encoding, errors=dialect.encoding_errors ) return cursor.var( cx_Oracle.LONG_STRING, size, cursor.arraysize, outconverter=outconverter, ) else: return cursor.var( cx_Oracle.LONG_STRING, size, cursor.arraysize, dialect._cursor_var_unicode_kwargs ) elif dialect.auto_convert_lobs and default_type in ( cx_Oracle.BLOB, ): return cursor.var( cx_Oracle.LONG_BINARY, size, cursor.arraysize, ) 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): opts = dict(url.query) # deprecated in 1.3 for opt in ("use_ansi", "auto_convert_lobs"): if opt in opts: util.warn_deprecated( "cx_oracle dialect option %r should only be passed to " "create_engine directly, not within the URL string" % opt ) util.coerce_kw_type(opts, opt, bool) setattr(self, opt, opts.pop(opt)) database = url.database service_name = opts.pop("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 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 self._cx_oracle_threaded is not None: opts.setdefault("threaded", self._cx_oracle_threaded) def convert_cx_oracle_constant(value): if isinstance(value, util.string_types): try: int_val = int(value) except ValueError: value = value.upper() return getattr(self.dbapi, value) else: return int_val else: return value util.coerce_kw_type(opts, "mode", convert_cx_oracle_constant) util.coerce_kw_type(opts, "threaded", bool) util.coerce_kw_type(opts, "events", bool) util.coerce_kw_type(opts, "purity", convert_cx_oracle_constant) 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 @util.deprecated( "1.2", "The create_xid() method of the cx_Oracle dialect is deprecated and " "will be removed in a future release. " "Two-phase transaction support is no longer functional " "in SQLAlchemy's cx_Oracle dialect as of cx_Oracle 6.0b1, which no " "longer supports the API that SQLAlchemy relied upon.", ) 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. """ 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	47.75 KB	2026-01-20 12:58
📄 provision.py from ... import create_engine from ... import exc from ...engine import url as sa_url from ...testing.provision import configure_follower from ...testing.provision import create_db from ...testing.provision import drop_db from ...testing.provision import follower_url_from_main from ...testing.provision import log from ...testing.provision import post_configure_engine from ...testing.provision import run_reap_dbs from ...testing.provision import stop_test_class from ...testing.provision import temp_table_keyword_args from ...testing.provision import update_db_opts @create_db.for_db("oracle") def _oracle_create_db(cfg, eng, ident): # NOTE: make sure you've run "ALTER DATABASE default tablespace users" or # similar, so that the default tablespace is not "system"; reflection will # fail otherwise with eng.connect() as conn: conn.execute("create user %s identified by xe" % ident) conn.execute("create user %s_ts1 identified by xe" % ident) conn.execute("create user %s_ts2 identified by xe" % ident) conn.execute("grant dba to %s" % (ident,)) conn.execute("grant unlimited tablespace to %s" % ident) conn.execute("grant unlimited tablespace to %s_ts1" % ident) conn.execute("grant unlimited tablespace to %s_ts2" % ident) @configure_follower.for_db("oracle") def _oracle_configure_follower(config, ident): config.test_schema = "%s_ts1" % ident config.test_schema_2 = "%s_ts2" % ident def _ora_drop_ignore(conn, dbname): try: conn.execute("drop user %s cascade" % dbname) log.info("Reaped db: %s", dbname) return True except exc.DatabaseError as err: log.warning("couldn't drop db: %s", err) return False @drop_db.for_db("oracle") def _oracle_drop_db(cfg, eng, ident): with eng.connect() as conn: # cx_Oracle seems to occasionally leak open connections when a large # suite it run, even if we confirm we have zero references to # connection objects. # while there is a "kill session" command in Oracle, # it unfortunately does not release the connection sufficiently. _ora_drop_ignore(conn, ident) _ora_drop_ignore(conn, "%s_ts1" % ident) _ora_drop_ignore(conn, "%s_ts2" % ident) @update_db_opts.for_db("oracle") def _oracle_update_db_opts(db_url, db_opts): pass @stop_test_class.for_db("oracle") def stop_test_class(config, db, cls): """run magic command to get rid of identity sequences # https://floo.bar/2019/11/29/drop-the-underlying-sequence-of-an-identity-column/ """ with db.begin() as conn: conn.execute("purge recyclebin") # clear statement cache on all connections that were used # https://github.com/oracle/python-cx_Oracle/issues/519 for cx_oracle_conn in _all_conns: try: sc = cx_oracle_conn.stmtcachesize except db.dialect.dbapi.InterfaceError: # connection closed pass else: cx_oracle_conn.stmtcachesize = 0 cx_oracle_conn.stmtcachesize = sc _all_conns.clear() _all_conns = set() @post_configure_engine.for_db("oracle") def _oracle_post_configure_engine(url, engine, follower_ident): from sqlalchemy import event @event.listens_for(engine, "checkout") def checkout(dbapi_con, con_record, con_proxy): _all_conns.add(dbapi_con) @run_reap_dbs.for_db("oracle") def _reap_oracle_dbs(url, idents): log.info("db reaper connecting to %r", url) eng = create_engine(url) with eng.connect() as conn: log.info("identifiers in file: %s", ", ".join(idents)) to_reap = conn.execute( "select u.username from all_users u where username " "like 'TEST_%' and not exists (select username " "from v$session where username=u.username)" ) all_names = {username.lower() for (username,) in to_reap} to_drop = set() for name in all_names: if name.endswith("_ts1") or name.endswith("_ts2"): continue elif name in idents: to_drop.add(name) if "%s_ts1" % name in all_names: to_drop.add("%s_ts1" % name) if "%s_ts2" % name in all_names: to_drop.add("%s_ts2" % name) dropped = total = 0 for total, username in enumerate(to_drop, 1): if _ora_drop_ignore(conn, username): dropped += 1 log.info( "Dropped %d out of %d stale databases detected", dropped, total ) @follower_url_from_main.for_db("oracle") def _oracle_follower_url_from_main(url, ident): url = sa_url.make_url(url) url.username = ident url.password = "xe" return url @temp_table_keyword_args.for_db("oracle") def _oracle_temp_table_keyword_args(cfg, eng): return { "prefixes": ["GLOBAL TEMPORARY"], "oracle_on_commit": "PRESERVE ROWS", }	4.88 KB	2026-01-20 12:58
📄 zxjdbc.py # oracle/zxjdbc.py # Copyright (C) 2005-2021 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php """ .. dialect:: oracle+zxjdbc :name: zxJDBC for Jython :dbapi: zxjdbc :connectstring: oracle+zxjdbc://user:pass@host/dbname :driverurl: http://www.oracle.com/technetwork/database/features/jdbc/index-091264.html .. note:: Jython is not supported by current versions of SQLAlchemy. The zxjdbc dialect should be considered as experimental. """ # noqa import collections import decimal import re from .base import OracleCompiler from .base import OracleDialect from .base import OracleExecutionContext from ... import sql from ... import types as sqltypes from ... import util from ...connectors.zxJDBC import ZxJDBCConnector from ...engine import result as _result from ...sql import expression SQLException = zxJDBC = None class _ZxJDBCDate(sqltypes.Date): def result_processor(self, dialect, coltype): def process(value): if value is None: return None else: return value.date() return process class _ZxJDBCNumeric(sqltypes.Numeric): def result_processor(self, dialect, coltype): # XXX: does the dialect return Decimal or not??? # if it does (in all cases), we could use a None processor as well as # the to_float generic processor if self.asdecimal: def process(value): if isinstance(value, decimal.Decimal): return value else: return decimal.Decimal(str(value)) else: def process(value): if isinstance(value, decimal.Decimal): return float(value) else: return value return process class OracleCompiler_zxjdbc(OracleCompiler): def returning_clause(self, stmt, returning_cols): self.returning_cols = list( expression._select_iterables(returning_cols) ) # within_columns_clause=False so that labels (foo AS bar) don't render columns = [ self.process(c, within_columns_clause=False) for c in self.returning_cols ] if not hasattr(self, "returning_parameters"): self.returning_parameters = [] binds = [] for i, col in enumerate(self.returning_cols): dbtype = col.type.dialect_impl(self.dialect).get_dbapi_type( self.dialect.dbapi ) self.returning_parameters.append((i + 1, dbtype)) bindparam = sql.bindparam( "ret_%d" % i, value=ReturningParam(dbtype) ) self.binds[bindparam.key] = bindparam binds.append( self.bindparam_string(self._truncate_bindparam(bindparam)) ) return "RETURNING " + ", ".join(columns) + " INTO " + ", ".join(binds) class OracleExecutionContext_zxjdbc(OracleExecutionContext): def pre_exec(self): if hasattr(self.compiled, "returning_parameters"): # prepare a zxJDBC statement so we can grab its underlying # OraclePreparedStatement's getReturnResultSet later self.statement = self.cursor.prepare(self.statement) def get_result_proxy(self): if hasattr(self.compiled, "returning_parameters"): rrs = None try: try: rrs = self.statement.__statement__.getReturnResultSet() next(rrs) except SQLException as sqle: msg = "%s [SQLCode: %d]" % ( sqle.getMessage(), sqle.getErrorCode(), ) if sqle.getSQLState() is not None: msg += " [SQLState: %s]" % sqle.getSQLState() raise zxJDBC.Error(msg) else: row = tuple( self.cursor.datahandler.getPyObject(rrs, index, dbtype) for index, dbtype in self.compiled.returning_parameters ) return ReturningResultProxy(self, row) finally: if rrs is not None: try: rrs.close() except SQLException: pass self.statement.close() return _result.ResultProxy(self) def create_cursor(self): cursor = self._dbapi_connection.cursor() cursor.datahandler = self.dialect.DataHandler(cursor.datahandler) return cursor class ReturningResultProxy(_result.FullyBufferedResultProxy): """ResultProxy backed by the RETURNING ResultSet results.""" def __init__(self, context, returning_row): self._returning_row = returning_row super(ReturningResultProxy, self).__init__(context) def _cursor_description(self): ret = [] for c in self.context.compiled.returning_cols: if hasattr(c, "name"): ret.append((c.name, c.type)) else: ret.append((c.anon_label, c.type)) return ret def _buffer_rows(self): return collections.deque([self._returning_row]) class ReturningParam(object): """A bindparam value representing a RETURNING parameter. Specially handled by OracleReturningDataHandler. """ def __init__(self, type_): self.type = type_ def __eq__(self, other): if isinstance(other, ReturningParam): return self.type == other.type return NotImplemented def __ne__(self, other): if isinstance(other, ReturningParam): return self.type != other.type return NotImplemented def __repr__(self): kls = self.__class__ return "<%s.%s object at 0x%x type=%s>" % ( kls.__module__, kls.__name__, id(self), self.type, ) class OracleDialect_zxjdbc(ZxJDBCConnector, OracleDialect): jdbc_db_name = "oracle" jdbc_driver_name = "oracle.jdbc.OracleDriver" statement_compiler = OracleCompiler_zxjdbc execution_ctx_cls = OracleExecutionContext_zxjdbc colspecs = util.update_copy( OracleDialect.colspecs, {sqltypes.Date: _ZxJDBCDate, sqltypes.Numeric: _ZxJDBCNumeric}, ) def __init__(self, args, kwargs): super(OracleDialect_zxjdbc, self).__init__(args, **kwargs) global SQLException, zxJDBC from java.sql import SQLException from com.ziclix.python.sql import zxJDBC from com.ziclix.python.sql.handler import OracleDataHandler class OracleReturningDataHandler(OracleDataHandler): """zxJDBC DataHandler that specially handles ReturningParam.""" def setJDBCObject(self, statement, index, object_, dbtype=None): if type(object_) is ReturningParam: statement.registerReturnParameter(index, object_.type) elif dbtype is None: OracleDataHandler.setJDBCObject( self, statement, index, object_ ) else: OracleDataHandler.setJDBCObject( self, statement, index, object_, dbtype ) self.DataHandler = OracleReturningDataHandler def initialize(self, connection): super(OracleDialect_zxjdbc, self).initialize(connection) self.implicit_returning = connection.connection.driverversion >= "10.2" def _create_jdbc_url(self, url): return "jdbc:oracle:thin:@%s:%s:%s" % ( url.host, url.port or 1521, url.database, ) def _get_server_version_info(self, connection): version = re.search( r"Release ([\d\.]+)", connection.connection.dbversion ).group(1) return tuple(int(x) for x in version.split(".")) dialect = OracleDialect_zxjdbc	8.01 KB	2026-01-20 12:58

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