541 lines
22 KiB
Python
541 lines
22 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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import datetime
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import decimal
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import os
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import platform
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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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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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_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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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)) 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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# 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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def create_cursor(self, name=None):
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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 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
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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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Check constraints by setting them to immediate. Return them to deferred
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afterward.
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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
|
|
|
|
@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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|
|
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class OracleParam:
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"""
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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
|
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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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param = Oracle_datetime.from_datetime(param)
|
|
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|
string_size = 0
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|
# Oracle doesn't recognize True and False correctly.
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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, datetime.timedelta)):
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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
|
|
# To get size right, we must consider bytes.
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self.force_bytes = force_text(param, cursor.charset, strings_only)
|
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if isinstance(self.force_bytes, str):
|
|
# We could optimize by only converting up to 4000 bytes here
|
|
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
|
|
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
|
|
else:
|
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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.
|
|
This can be used generally for any other object that should be passed into
|
|
Cursor.execute as-is.
|
|
"""
|
|
|
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def __init__(self, var):
|
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self.var = var
|
|
|
|
def bind_parameter(self, cursor):
|
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return self.var
|
|
|
|
def __getattr__(self, key):
|
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return getattr(self.var, key)
|
|
|
|
def __setattr__(self, key, value):
|
|
if key == 'var':
|
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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)
|