179b247e07
NULL cannot be compare with standard operators on Oracle, it works only with IS NULL and IS NOT NULL operators. Therefore 'OR ... IS NULL' condition in NullBooleanField's check constraint is redundant. Nullability is checked in a separate constraint.
541 lines
22 KiB
Python
541 lines
22 KiB
Python
"""
|
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Oracle database backend for Django.
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|
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Requires cx_Oracle: http://cx-oracle.sourceforge.net/
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"""
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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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|
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from django.conf import settings
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from django.core.exceptions import ImproperlyConfigured
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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.utils.encoding import force_bytes, force_text
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from django.utils.functional import cached_property
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|
|
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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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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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|
|
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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', '.AL32UTF8'),
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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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|
|
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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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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 # NOQA isort:skip
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from .creation import DatabaseCreation # NOQA isort:skip
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from .features import DatabaseFeatures # NOQA isort:skip
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from .introspection import DatabaseIntrospection # NOQA isort:skip
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from .operations import DatabaseOperations # NOQA isort:skip
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from .schema import DatabaseSchemaEditor # NOQA isort:skip
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from .utils import Oracle_datetime # NOQA isort:skip
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from .validation import DatabaseValidation # NOQA isort:skip
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class _UninitializedOperatorsDescriptor:
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def __get__(self, instance, cls=None):
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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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display_name = '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) GENERATED BY DEFAULT ON NULL AS IDENTITY',
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'BigAutoField': 'NUMBER(19) GENERATED BY DEFAULT ON NULL AS IDENTITY',
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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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'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)',
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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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# Oracle doesn't support a database index on these columns.
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_limited_data_types = ('clob', 'nclob', 'blob')
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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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# Classes instantiated in __init__().
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client_class = DatabaseClient
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creation_class = DatabaseCreation
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features_class = DatabaseFeatures
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introspection_class = DatabaseIntrospection
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ops_class = DatabaseOperations
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validation_class = DatabaseValidation
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def __init__(self, *args, **kwargs):
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super().__init__(*args, **kwargs)
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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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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']:
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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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return Database.connect(self._connect_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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)
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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 Database.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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self.connection.stmtcachesize = 20
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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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|
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|
def create_cursor(self, name=None):
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return FormatStylePlaceholderCursor(self.connection)
|
|
|
|
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 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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raise utils.IntegrityError(*tuple(e.args))
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raise
|
|
|
|
# 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):
|
|
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',
|
|
})
|
|
|
|
def _set_autocommit(self, autocommit):
|
|
with self.wrap_database_errors:
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|
self.connection.autocommit = autocommit
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|
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|
def check_constraints(self, table_names=None):
|
|
"""
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|
Check constraints by setting them to immediate. Return them to deferred
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|
afterward.
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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):
|
|
try:
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|
self.connection.ping()
|
|
except Database.Error:
|
|
return False
|
|
else:
|
|
return True
|
|
|
|
@cached_property
|
|
def oracle_full_version(self):
|
|
with self.temporary_connection():
|
|
return self.connection.version
|
|
|
|
@cached_property
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|
def oracle_version(self):
|
|
try:
|
|
return int(self.oracle_full_version.split('.')[0])
|
|
except ValueError:
|
|
return None
|
|
|
|
|
|
class OracleParam:
|
|
"""
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|
Wrapper object for formatting parameters for Oracle. If the string
|
|
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
|
|
parameter when executing the query.
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"""
|
|
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|
def __init__(self, param, cursor, strings_only=False):
|
|
# With raw SQL queries, datetimes can reach this function
|
|
# without being converted by DateTimeField.get_db_prep_value.
|
|
if settings.USE_TZ and (isinstance(param, datetime.datetime) and
|
|
not isinstance(param, Oracle_datetime)):
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|
param = Oracle_datetime.from_datetime(param)
|
|
|
|
string_size = 0
|
|
# Oracle doesn't recognize True and False correctly.
|
|
if param is True:
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|
param = 1
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|
elif param is False:
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|
param = 0
|
|
if hasattr(param, 'bind_parameter'):
|
|
self.force_bytes = param.bind_parameter(cursor)
|
|
elif isinstance(param, (Database.Binary, datetime.timedelta)):
|
|
self.force_bytes = param
|
|
else:
|
|
# To transmit to the database, we need Unicode if supported
|
|
# To get size right, we must consider bytes.
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|
self.force_bytes = force_text(param, cursor.charset, strings_only)
|
|
if isinstance(self.force_bytes, str):
|
|
# 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))
|
|
if hasattr(param, 'input_size'):
|
|
# If parameter has `input_size` attribute, use that.
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self.input_size = param.input_size
|
|
elif string_size > 4000:
|
|
# Mark any string param greater than 4000 characters as a CLOB.
|
|
self.input_size = Database.CLOB
|
|
else:
|
|
self.input_size = None
|
|
|
|
|
|
class VariableWrapper:
|
|
"""
|
|
An adapter class for cursor variables that prevents the wrapped object
|
|
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
|
|
Cursor.execute as-is.
|
|
"""
|
|
|
|
def __init__(self, var):
|
|
self.var = var
|
|
|
|
def bind_parameter(self, cursor):
|
|
return self.var
|
|
|
|
def __getattr__(self, key):
|
|
return getattr(self.var, key)
|
|
|
|
def __setattr__(self, key, value):
|
|
if key == 'var':
|
|
self.__dict__[key] = value
|
|
else:
|
|
setattr(self.var, key, value)
|
|
|
|
|
|
class FormatStylePlaceholderCursor:
|
|
"""
|
|
Django uses "format" (e.g. '%s') style placeholders, but Oracle uses ":var"
|
|
style. This fixes it -- but note that if you want to use a literal "%s" in
|
|
a query, you'll need to use "%%s".
|
|
|
|
We also do automatic conversion between Unicode on the Python side and
|
|
UTF-8 -- for talking to Oracle -- in here.
|
|
"""
|
|
charset = 'utf-8'
|
|
|
|
def __init__(self, connection):
|
|
self.cursor = connection.cursor()
|
|
self.cursor.outputtypehandler = self._output_type_handler
|
|
# The default for cx_Oracle < 5.3 is 50.
|
|
self.cursor.arraysize = 100
|
|
|
|
@staticmethod
|
|
def _output_number_converter(value):
|
|
return decimal.Decimal(value) if '.' in value else int(value)
|
|
|
|
@staticmethod
|
|
def _output_type_handler(cursor, name, defaultType, length, precision, scale):
|
|
"""
|
|
Called for each db column fetched from cursors. Return numbers as the
|
|
appropriate Python type.
|
|
"""
|
|
if defaultType == Database.NUMBER:
|
|
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.
|
|
outconverter = FormatStylePlaceholderCursor._output_number_converter
|
|
else:
|
|
# FLOAT column: binary-precision floating point.
|
|
# This comes from FloatField columns.
|
|
outconverter = float
|
|
elif precision > 0:
|
|
# NUMBER(p,s) column: decimal-precision fixed point.
|
|
# This comes from IntegerField and DecimalField columns.
|
|
outconverter = int if scale == 0 else decimal.Decimal
|
|
else:
|
|
# 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.
|
|
outconverter = FormatStylePlaceholderCursor._output_number_converter
|
|
return cursor.var(
|
|
Database.STRING,
|
|
size=255,
|
|
arraysize=cursor.arraysize,
|
|
outconverter=outconverter,
|
|
)
|
|
|
|
def _format_params(self, params):
|
|
try:
|
|
return {k: OracleParam(v, self, True) for k, v in params.items()}
|
|
except AttributeError:
|
|
return tuple(OracleParam(p, self, True) for p in params)
|
|
|
|
def _guess_input_sizes(self, params_list):
|
|
# Try dict handling; if that fails, treat as sequence
|
|
if hasattr(params_list[0], 'keys'):
|
|
sizes = {}
|
|
for params in params_list:
|
|
for k, value in params.items():
|
|
if value.input_size:
|
|
sizes[k] = value.input_size
|
|
self.setinputsizes(**sizes)
|
|
else:
|
|
# It's not a list of dicts; it's a list of sequences
|
|
sizes = [None] * len(params_list[0])
|
|
for params in params_list:
|
|
for i, value in enumerate(params):
|
|
if value.input_size:
|
|
sizes[i] = value.input_size
|
|
self.setinputsizes(*sizes)
|
|
|
|
def _param_generator(self, params):
|
|
# Try dict handling; if that fails, treat as sequence
|
|
if hasattr(params, 'items'):
|
|
return {k: v.force_bytes for k, v in params.items()}
|
|
else:
|
|
return [p.force_bytes for p in params]
|
|
|
|
def _fix_for_params(self, query, params, unify_by_values=False):
|
|
# cx_Oracle wants no trailing ';' for SQL statements. For PL/SQL, it
|
|
# it does want a trailing ';' but not a trailing '/'. However, these
|
|
# characters must be included in the original query in case the query
|
|
# is being passed to SQL*Plus.
|
|
if query.endswith(';') or query.endswith('/'):
|
|
query = query[:-1]
|
|
if params is None:
|
|
params = []
|
|
elif hasattr(params, 'keys'):
|
|
# Handle params as dict
|
|
args = {k: ":%s" % k for k in params}
|
|
query = query % args
|
|
elif unify_by_values and len(params) > 0:
|
|
# Handle params as a dict with unified query parameters by their
|
|
# values. It can be used only in single query execute() because
|
|
# executemany() shares the formatted query with each of the params
|
|
# list. e.g. for input params = [0.75, 2, 0.75, 'sth', 0.75]
|
|
# params_dict = {0.75: ':arg0', 2: ':arg1', 'sth': ':arg2'}
|
|
# args = [':arg0', ':arg1', ':arg0', ':arg2', ':arg0']
|
|
# params = {':arg0': 0.75, ':arg1': 2, ':arg2': 'sth'}
|
|
params_dict = {param: ':arg%d' % i for i, param in enumerate(set(params))}
|
|
args = [params_dict[param] for param in params]
|
|
params = {value: key for key, value in params_dict.items()}
|
|
query = query % tuple(args)
|
|
else:
|
|
# Handle params as sequence
|
|
args = [(':arg%d' % i) for i in range(len(params))]
|
|
query = query % tuple(args)
|
|
return query, self._format_params(params)
|
|
|
|
def execute(self, query, params=None):
|
|
query, params = self._fix_for_params(query, params, unify_by_values=True)
|
|
self._guess_input_sizes([params])
|
|
return self.cursor.execute(query, self._param_generator(params))
|
|
|
|
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)
|
|
return self.cursor.executemany(query, [self._param_generator(p) for p in formatted])
|
|
|
|
def fetchmany(self, size=None):
|
|
if size is None:
|
|
size = self.arraysize
|
|
return tuple(self.cursor.fetchmany(size))
|
|
|
|
def fetchall(self):
|
|
return tuple(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):
|
|
return getattr(self.cursor, attr)
|
|
|
|
def __iter__(self):
|
|
return iter(self.cursor)
|