609 lines
24 KiB
Python
609 lines
24 KiB
Python
"""
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Oracle database backend for Django.
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Requires cx_Oracle: http://cx-oracle.sourceforge.net/
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"""
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from __future__ import unicode_literals
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import datetime
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import decimal
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import os
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import platform
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import sys
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import warnings
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from django.conf import settings
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from django.db import utils
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from django.db.backends.base.base import BaseDatabaseWrapper
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from django.db.backends.base.validation import BaseDatabaseValidation
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from django.utils import six, timezone
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from django.utils.deprecation import RemovedInDjango20Warning
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from django.utils.duration import duration_string
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from django.utils.encoding import force_bytes, force_text
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from django.utils.functional import cached_property
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def _setup_environment(environ):
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# Cygwin requires some special voodoo to set the environment variables
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# properly so that Oracle will see them.
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if platform.system().upper().startswith('CYGWIN'):
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try:
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import ctypes
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except ImportError as e:
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from django.core.exceptions import ImproperlyConfigured
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raise ImproperlyConfigured("Error loading ctypes: %s; "
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"the Oracle backend requires ctypes to "
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"operate correctly under Cygwin." % e)
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kernel32 = ctypes.CDLL('kernel32')
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for name, value in environ:
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kernel32.SetEnvironmentVariableA(name, value)
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else:
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os.environ.update(environ)
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_setup_environment([
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# Oracle takes client-side character set encoding from the environment.
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('NLS_LANG', '.UTF8'),
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# This prevents unicode from getting mangled by getting encoded into the
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# potentially non-unicode database character set.
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('ORA_NCHAR_LITERAL_REPLACE', 'TRUE'),
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])
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try:
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import cx_Oracle as Database
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except ImportError as e:
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from django.core.exceptions import ImproperlyConfigured
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raise ImproperlyConfigured("Error loading cx_Oracle module: %s" % e)
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# Some of these import cx_Oracle, so import them after checking if it's installed.
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from .client import DatabaseClient # isort:skip
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from .creation import DatabaseCreation # isort:skip
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from .features import DatabaseFeatures # isort:skip
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from .introspection import DatabaseIntrospection # isort:skip
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from .operations import DatabaseOperations # isort:skip
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from .schema import DatabaseSchemaEditor # isort:skip
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from .utils import Oracle_datetime, convert_unicode # isort:skip
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DatabaseError = Database.DatabaseError
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IntegrityError = Database.IntegrityError
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class _UninitializedOperatorsDescriptor(object):
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def __get__(self, instance, owner):
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# If connection.operators is looked up before a connection has been
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# created, transparently initialize connection.operators to avert an
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# AttributeError.
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if instance is None:
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raise AttributeError("operators not available as class attribute")
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# Creating a cursor will initialize the operators.
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instance.cursor().close()
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return instance.__dict__['operators']
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class DatabaseWrapper(BaseDatabaseWrapper):
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vendor = 'oracle'
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# This dictionary maps Field objects to their associated Oracle column
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# types, as strings. Column-type strings can contain format strings; they'll
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# be interpolated against the values of Field.__dict__ before being output.
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# If a column type is set to None, it won't be included in the output.
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#
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# Any format strings starting with "qn_" are quoted before being used in the
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# output (the "qn_" prefix is stripped before the lookup is performed.
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data_types = {
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'AutoField': 'NUMBER(11)',
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'BinaryField': 'BLOB',
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'BooleanField': 'NUMBER(1)',
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'CharField': 'NVARCHAR2(%(max_length)s)',
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'CommaSeparatedIntegerField': 'VARCHAR2(%(max_length)s)',
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'DateField': 'DATE',
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'DateTimeField': 'TIMESTAMP',
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'DecimalField': 'NUMBER(%(max_digits)s, %(decimal_places)s)',
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'DurationField': 'INTERVAL DAY(9) TO SECOND(6)',
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'FileField': 'NVARCHAR2(%(max_length)s)',
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'FilePathField': 'NVARCHAR2(%(max_length)s)',
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'FloatField': 'DOUBLE PRECISION',
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'IntegerField': 'NUMBER(11)',
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'BigIntegerField': 'NUMBER(19)',
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'IPAddressField': 'VARCHAR2(15)',
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'GenericIPAddressField': 'VARCHAR2(39)',
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'NullBooleanField': 'NUMBER(1)',
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'OneToOneField': 'NUMBER(11)',
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'PositiveIntegerField': 'NUMBER(11)',
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'PositiveSmallIntegerField': 'NUMBER(11)',
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'SlugField': 'NVARCHAR2(%(max_length)s)',
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'SmallIntegerField': 'NUMBER(11)',
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'TextField': 'NCLOB',
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'TimeField': 'TIMESTAMP',
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'URLField': 'VARCHAR2(%(max_length)s)',
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'UUIDField': 'VARCHAR2(32)',
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}
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data_type_check_constraints = {
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'BooleanField': '%(qn_column)s IN (0,1)',
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'NullBooleanField': '(%(qn_column)s IN (0,1)) OR (%(qn_column)s IS NULL)',
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'PositiveIntegerField': '%(qn_column)s >= 0',
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'PositiveSmallIntegerField': '%(qn_column)s >= 0',
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}
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operators = _UninitializedOperatorsDescriptor()
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_standard_operators = {
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'exact': '= %s',
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'iexact': '= UPPER(%s)',
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'contains': "LIKE TRANSLATE(%s USING NCHAR_CS) ESCAPE TRANSLATE('\\' USING NCHAR_CS)",
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'icontains': "LIKE UPPER(TRANSLATE(%s USING NCHAR_CS)) ESCAPE TRANSLATE('\\' USING NCHAR_CS)",
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'gt': '> %s',
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'gte': '>= %s',
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'lt': '< %s',
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'lte': '<= %s',
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'startswith': "LIKE TRANSLATE(%s USING NCHAR_CS) ESCAPE TRANSLATE('\\' USING NCHAR_CS)",
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'endswith': "LIKE TRANSLATE(%s USING NCHAR_CS) ESCAPE TRANSLATE('\\' USING NCHAR_CS)",
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'istartswith': "LIKE UPPER(TRANSLATE(%s USING NCHAR_CS)) ESCAPE TRANSLATE('\\' USING NCHAR_CS)",
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'iendswith': "LIKE UPPER(TRANSLATE(%s USING NCHAR_CS)) ESCAPE TRANSLATE('\\' USING NCHAR_CS)",
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}
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_likec_operators = _standard_operators.copy()
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_likec_operators.update({
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'contains': "LIKEC %s ESCAPE '\\'",
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'icontains': "LIKEC UPPER(%s) ESCAPE '\\'",
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'startswith': "LIKEC %s ESCAPE '\\'",
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'endswith': "LIKEC %s ESCAPE '\\'",
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'istartswith': "LIKEC UPPER(%s) ESCAPE '\\'",
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'iendswith': "LIKEC UPPER(%s) ESCAPE '\\'",
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})
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# The patterns below are used to generate SQL pattern lookup clauses when
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# the right-hand side of the lookup isn't a raw string (it might be an expression
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# or the result of a bilateral transformation).
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# In those cases, special characters for LIKE operators (e.g. \, *, _) should be
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# escaped on database side.
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#
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# Note: we use str.format() here for readability as '%' is used as a wildcard for
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# the LIKE operator.
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pattern_esc = r"REPLACE(REPLACE(REPLACE({}, '\', '\\'), '%%', '\%%'), '_', '\_')"
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_pattern_ops = {
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'contains': "'%%' || {} || '%%'",
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'icontains': "'%%' || UPPER({}) || '%%'",
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'startswith': "{} || '%%'",
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'istartswith': "UPPER({}) || '%%'",
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'endswith': "'%%' || {}",
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'iendswith': "'%%' || UPPER({})",
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}
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_standard_pattern_ops = {k: "LIKE TRANSLATE( " + v + " USING NCHAR_CS)"
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" ESCAPE TRANSLATE('\\' USING NCHAR_CS)"
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for k, v in _pattern_ops.items()}
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_likec_pattern_ops = {k: "LIKEC " + v + " ESCAPE '\\'"
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for k, v in _pattern_ops.items()}
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Database = Database
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SchemaEditorClass = DatabaseSchemaEditor
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def __init__(self, *args, **kwargs):
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super(DatabaseWrapper, self).__init__(*args, **kwargs)
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self.features = DatabaseFeatures(self)
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use_returning_into = self.settings_dict["OPTIONS"].get('use_returning_into', True)
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self.features.can_return_id_from_insert = use_returning_into
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self.ops = DatabaseOperations(self)
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self.client = DatabaseClient(self)
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self.creation = DatabaseCreation(self)
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self.introspection = DatabaseIntrospection(self)
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self.validation = BaseDatabaseValidation(self)
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def _connect_string(self):
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settings_dict = self.settings_dict
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if not settings_dict['HOST'].strip():
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settings_dict['HOST'] = 'localhost'
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if settings_dict['PORT'].strip():
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dsn = Database.makedsn(settings_dict['HOST'],
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int(settings_dict['PORT']),
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settings_dict['NAME'])
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else:
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dsn = settings_dict['NAME']
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return "%s/%s@%s" % (settings_dict['USER'],
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settings_dict['PASSWORD'], dsn)
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def get_connection_params(self):
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conn_params = self.settings_dict['OPTIONS'].copy()
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if 'use_returning_into' in conn_params:
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del conn_params['use_returning_into']
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return conn_params
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def get_new_connection(self, conn_params):
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conn_string = convert_unicode(self._connect_string())
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return Database.connect(conn_string, **conn_params)
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def init_connection_state(self):
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cursor = self.create_cursor()
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# Set the territory first. The territory overrides NLS_DATE_FORMAT
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# and NLS_TIMESTAMP_FORMAT to the territory default. When all of
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# these are set in single statement it isn't clear what is supposed
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# to happen.
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cursor.execute("ALTER SESSION SET NLS_TERRITORY = 'AMERICA'")
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# Set Oracle date to ANSI date format. This only needs to execute
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# once when we create a new connection. We also set the Territory
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# to 'AMERICA' which forces Sunday to evaluate to a '1' in
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# TO_CHAR().
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cursor.execute(
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"ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS'"
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" NLS_TIMESTAMP_FORMAT = 'YYYY-MM-DD HH24:MI:SS.FF'"
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+ (" TIME_ZONE = 'UTC'" if settings.USE_TZ else ''))
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cursor.close()
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if 'operators' not in self.__dict__:
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# Ticket #14149: Check whether our LIKE implementation will
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# work for this connection or we need to fall back on LIKEC.
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# This check is performed only once per DatabaseWrapper
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# instance per thread, since subsequent connections will use
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# the same settings.
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cursor = self.create_cursor()
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try:
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cursor.execute("SELECT 1 FROM DUAL WHERE DUMMY %s"
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% self._standard_operators['contains'],
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['X'])
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except DatabaseError:
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self.operators = self._likec_operators
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self.pattern_ops = self._likec_pattern_ops
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else:
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self.operators = self._standard_operators
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self.pattern_ops = self._standard_pattern_ops
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cursor.close()
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try:
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self.connection.stmtcachesize = 20
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except AttributeError:
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# Django docs specify cx_Oracle version 4.3.1 or higher, but
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# stmtcachesize is available only in 4.3.2 and up.
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pass
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# Ensure all changes are preserved even when AUTOCOMMIT is False.
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if not self.get_autocommit():
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self.commit()
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def create_cursor(self):
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return FormatStylePlaceholderCursor(self.connection)
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def _commit(self):
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if self.connection is not None:
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try:
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return self.connection.commit()
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except Database.DatabaseError as e:
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# cx_Oracle 5.0.4 raises a cx_Oracle.DatabaseError exception
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# with the following attributes and values:
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# code = 2091
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# message = 'ORA-02091: transaction rolled back
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# 'ORA-02291: integrity constraint (TEST_DJANGOTEST.SYS
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# _C00102056) violated - parent key not found'
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# We convert that particular case to our IntegrityError exception
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x = e.args[0]
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if hasattr(x, 'code') and hasattr(x, 'message') \
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and x.code == 2091 and 'ORA-02291' in x.message:
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six.reraise(utils.IntegrityError, utils.IntegrityError(*tuple(e.args)), sys.exc_info()[2])
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raise
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# Oracle doesn't support releasing savepoints. But we fake them when query
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# logging is enabled to keep query counts consistent with other backends.
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def _savepoint_commit(self, sid):
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if self.queries_logged:
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self.queries_log.append({
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'sql': '-- RELEASE SAVEPOINT %s (faked)' % self.ops.quote_name(sid),
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'time': '0.000',
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})
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def _set_autocommit(self, autocommit):
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with self.wrap_database_errors:
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self.connection.autocommit = autocommit
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def check_constraints(self, table_names=None):
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"""
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To check constraints, we set constraints to immediate. Then, when, we're done we must ensure they
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are returned to deferred.
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"""
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self.cursor().execute('SET CONSTRAINTS ALL IMMEDIATE')
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self.cursor().execute('SET CONSTRAINTS ALL DEFERRED')
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def is_usable(self):
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try:
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self.connection.ping()
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except Database.Error:
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return False
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else:
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return True
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@cached_property
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def oracle_full_version(self):
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with self.temporary_connection():
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return self.connection.version
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@cached_property
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def oracle_version(self):
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try:
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return int(self.oracle_full_version.split('.')[0])
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except ValueError:
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return None
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class OracleParam(object):
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"""
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Wrapper object for formatting parameters for Oracle. If the string
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representation of the value is large enough (greater than 4000 characters)
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the input size needs to be set as CLOB. Alternatively, if the parameter
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has an `input_size` attribute, then the value of the `input_size` attribute
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will be used instead. Otherwise, no input size will be set for the
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parameter when executing the query.
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"""
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def __init__(self, param, cursor, strings_only=False):
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# With raw SQL queries, datetimes can reach this function
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# without being converted by DateTimeField.get_db_prep_value.
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if settings.USE_TZ and (isinstance(param, datetime.datetime) and
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not isinstance(param, Oracle_datetime)):
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if timezone.is_aware(param):
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warnings.warn(
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"The Oracle database adapter received an aware datetime (%s), "
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"probably from cursor.execute(). Update your code to pass a "
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"naive datetime in the database connection's time zone (UTC by "
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"default).", RemovedInDjango20Warning)
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param = param.astimezone(timezone.utc).replace(tzinfo=None)
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param = Oracle_datetime.from_datetime(param)
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if isinstance(param, datetime.timedelta):
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param = duration_string(param)
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if ' ' not in param:
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param = '0 ' + param
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string_size = 0
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# Oracle doesn't recognize True and False correctly in Python 3.
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# The conversion done below works both in 2 and 3.
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if param is True:
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param = 1
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elif param is False:
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param = 0
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if hasattr(param, 'bind_parameter'):
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self.force_bytes = param.bind_parameter(cursor)
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elif isinstance(param, Database.Binary):
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self.force_bytes = param
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else:
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# To transmit to the database, we need Unicode if supported
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# To get size right, we must consider bytes.
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self.force_bytes = convert_unicode(param, cursor.charset,
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strings_only)
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if isinstance(self.force_bytes, six.string_types):
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# We could optimize by only converting up to 4000 bytes here
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string_size = len(force_bytes(param, cursor.charset, strings_only))
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if hasattr(param, 'input_size'):
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# If parameter has `input_size` attribute, use that.
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self.input_size = param.input_size
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elif string_size > 4000:
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# Mark any string param greater than 4000 characters as a CLOB.
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self.input_size = Database.CLOB
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else:
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self.input_size = None
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class VariableWrapper(object):
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"""
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An adapter class for cursor variables that prevents the wrapped object
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from being converted into a string when used to instantiate an OracleParam.
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This can be used generally for any other object that should be passed into
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Cursor.execute as-is.
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"""
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def __init__(self, var):
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self.var = var
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def bind_parameter(self, cursor):
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return self.var
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def __getattr__(self, key):
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return getattr(self.var, key)
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def __setattr__(self, key, value):
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if key == 'var':
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self.__dict__[key] = value
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else:
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setattr(self.var, key, value)
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class FormatStylePlaceholderCursor(object):
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"""
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Django uses "format" (e.g. '%s') style placeholders, but Oracle uses ":var"
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style. This fixes it -- but note that if you want to use a literal "%s" in
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a query, you'll need to use "%%s".
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We also do automatic conversion between Unicode on the Python side and
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UTF-8 -- for talking to Oracle -- in here.
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"""
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charset = 'utf-8'
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def __init__(self, connection):
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self.cursor = connection.cursor()
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# Necessary to retrieve decimal values without rounding error.
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self.cursor.numbersAsStrings = True
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# Default arraysize of 1 is highly sub-optimal.
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self.cursor.arraysize = 100
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def _format_params(self, params):
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try:
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return {k: OracleParam(v, self, True) for k, v in params.items()}
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except AttributeError:
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return tuple(OracleParam(p, self, True) for p in params)
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def _guess_input_sizes(self, params_list):
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# Try dict handling; if that fails, treat as sequence
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if hasattr(params_list[0], 'keys'):
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sizes = {}
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for params in params_list:
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for k, value in params.items():
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if value.input_size:
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sizes[k] = value.input_size
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self.setinputsizes(**sizes)
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else:
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# It's not a list of dicts; it's a list of sequences
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sizes = [None] * len(params_list[0])
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for params in params_list:
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for i, value in enumerate(params):
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if value.input_size:
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sizes[i] = value.input_size
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self.setinputsizes(*sizes)
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def _param_generator(self, params):
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# Try dict handling; if that fails, treat as sequence
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if hasattr(params, 'items'):
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return {k: v.force_bytes for k, v in params.items()}
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else:
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return [p.force_bytes for p in params]
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def _fix_for_params(self, query, params):
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# cx_Oracle wants no trailing ';' for SQL statements. For PL/SQL, it
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# it does want a trailing ';' but not a trailing '/'. However, these
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# characters must be included in the original query in case the query
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# is being passed to SQL*Plus.
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if query.endswith(';') or query.endswith('/'):
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query = query[:-1]
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if params is None:
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params = []
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query = convert_unicode(query, self.charset)
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elif hasattr(params, 'keys'):
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# Handle params as dict
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|
args = {k: ":%s" % k for k in params.keys()}
|
|
query = convert_unicode(query % args, self.charset)
|
|
else:
|
|
# Handle params as sequence
|
|
args = [(':arg%d' % i) for i in range(len(params))]
|
|
query = convert_unicode(query % tuple(args), self.charset)
|
|
return query, self._format_params(params)
|
|
|
|
def execute(self, query, params=None):
|
|
query, params = self._fix_for_params(query, params)
|
|
self._guess_input_sizes([params])
|
|
try:
|
|
return self.cursor.execute(query, self._param_generator(params))
|
|
except Database.DatabaseError as e:
|
|
# cx_Oracle <= 4.4.0 wrongly raises a DatabaseError for ORA-01400.
|
|
if hasattr(e.args[0], 'code') and e.args[0].code == 1400 and not isinstance(e, IntegrityError):
|
|
six.reraise(utils.IntegrityError, utils.IntegrityError(*tuple(e.args)), sys.exc_info()[2])
|
|
raise
|
|
|
|
def executemany(self, query, params=None):
|
|
if not params:
|
|
# No params given, nothing to do
|
|
return None
|
|
# uniform treatment for sequences and iterables
|
|
params_iter = iter(params)
|
|
query, firstparams = self._fix_for_params(query, next(params_iter))
|
|
# we build a list of formatted params; as we're going to traverse it
|
|
# more than once, we can't make it lazy by using a generator
|
|
formatted = [firstparams] + [self._format_params(p) for p in params_iter]
|
|
self._guess_input_sizes(formatted)
|
|
try:
|
|
return self.cursor.executemany(query,
|
|
[self._param_generator(p) for p in formatted])
|
|
except Database.DatabaseError as e:
|
|
# cx_Oracle <= 4.4.0 wrongly raises a DatabaseError for ORA-01400.
|
|
if hasattr(e.args[0], 'code') and e.args[0].code == 1400 and not isinstance(e, IntegrityError):
|
|
six.reraise(utils.IntegrityError, utils.IntegrityError(*tuple(e.args)), sys.exc_info()[2])
|
|
raise
|
|
|
|
def fetchone(self):
|
|
row = self.cursor.fetchone()
|
|
if row is None:
|
|
return row
|
|
return _rowfactory(row, self.cursor)
|
|
|
|
def fetchmany(self, size=None):
|
|
if size is None:
|
|
size = self.arraysize
|
|
return tuple(_rowfactory(r, self.cursor) for r in self.cursor.fetchmany(size))
|
|
|
|
def fetchall(self):
|
|
return tuple(_rowfactory(r, self.cursor) for r in self.cursor.fetchall())
|
|
|
|
def close(self):
|
|
try:
|
|
self.cursor.close()
|
|
except Database.InterfaceError:
|
|
# already closed
|
|
pass
|
|
|
|
def var(self, *args):
|
|
return VariableWrapper(self.cursor.var(*args))
|
|
|
|
def arrayvar(self, *args):
|
|
return VariableWrapper(self.cursor.arrayvar(*args))
|
|
|
|
def __getattr__(self, attr):
|
|
if attr in self.__dict__:
|
|
return self.__dict__[attr]
|
|
else:
|
|
return getattr(self.cursor, attr)
|
|
|
|
def __iter__(self):
|
|
return CursorIterator(self.cursor)
|
|
|
|
|
|
class CursorIterator(six.Iterator):
|
|
"""
|
|
Cursor iterator wrapper that invokes our custom row factory.
|
|
"""
|
|
|
|
def __init__(self, cursor):
|
|
self.cursor = cursor
|
|
self.iter = iter(cursor)
|
|
|
|
def __iter__(self):
|
|
return self
|
|
|
|
def __next__(self):
|
|
return _rowfactory(next(self.iter), self.cursor)
|
|
|
|
|
|
def _rowfactory(row, cursor):
|
|
# Cast numeric values as the appropriate Python type based upon the
|
|
# cursor description, and convert strings to unicode.
|
|
casted = []
|
|
for value, desc in zip(row, cursor.description):
|
|
if value is not None and desc[1] is Database.NUMBER:
|
|
precision, scale = desc[4:6]
|
|
if scale == -127:
|
|
if precision == 0:
|
|
# NUMBER column: decimal-precision floating point
|
|
# This will normally be an integer from a sequence,
|
|
# but it could be a decimal value.
|
|
if '.' in value:
|
|
value = decimal.Decimal(value)
|
|
else:
|
|
value = int(value)
|
|
else:
|
|
# FLOAT column: binary-precision floating point.
|
|
# This comes from FloatField columns.
|
|
value = float(value)
|
|
elif precision > 0:
|
|
# NUMBER(p,s) column: decimal-precision fixed point.
|
|
# This comes from IntField and DecimalField columns.
|
|
if scale == 0:
|
|
value = int(value)
|
|
else:
|
|
value = decimal.Decimal(value)
|
|
elif '.' in value:
|
|
# No type information. This normally comes from a
|
|
# mathematical expression in the SELECT list. Guess int
|
|
# or Decimal based on whether it has a decimal point.
|
|
value = decimal.Decimal(value)
|
|
else:
|
|
value = int(value)
|
|
elif desc[1] in (Database.STRING, Database.FIXED_CHAR,
|
|
Database.LONG_STRING):
|
|
value = to_unicode(value)
|
|
casted.append(value)
|
|
return tuple(casted)
|
|
|
|
|
|
def to_unicode(s):
|
|
"""
|
|
Convert strings to Unicode objects (and return all other data types
|
|
unchanged).
|
|
"""
|
|
if isinstance(s, six.string_types):
|
|
return force_text(s)
|
|
return s
|