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Diffstat (limited to 'lib/python2.7/site-packages/django/db/backends/oracle/base.py')
| -rw-r--r-- | lib/python2.7/site-packages/django/db/backends/oracle/base.py | 961 |
1 files changed, 961 insertions, 0 deletions
diff --git a/lib/python2.7/site-packages/django/db/backends/oracle/base.py b/lib/python2.7/site-packages/django/db/backends/oracle/base.py new file mode 100644 index 0000000..11ab574 --- /dev/null +++ b/lib/python2.7/site-packages/django/db/backends/oracle/base.py @@ -0,0 +1,961 @@ +""" +Oracle database backend for Django. + +Requires cx_Oracle: http://cx-oracle.sourceforge.net/ +""" +from __future__ import unicode_literals + +import decimal +import re +import sys +import warnings + +def _setup_environment(environ): + import platform + # Cygwin requires some special voodoo to set the environment variables + # properly so that Oracle will see them. + if platform.system().upper().startswith('CYGWIN'): + try: + import ctypes + except ImportError as e: + from django.core.exceptions import ImproperlyConfigured + raise ImproperlyConfigured("Error loading ctypes: %s; " + "the Oracle backend requires ctypes to " + "operate correctly under Cygwin." % e) + kernel32 = ctypes.CDLL('kernel32') + for name, value in environ: + kernel32.SetEnvironmentVariableA(name, value) + else: + import os + os.environ.update(environ) + +_setup_environment([ + # Oracle takes client-side character set encoding from the environment. + ('NLS_LANG', '.UTF8'), + # This prevents unicode from getting mangled by getting encoded into the + # potentially non-unicode database character set. + ('ORA_NCHAR_LITERAL_REPLACE', 'TRUE'), +]) + + +try: + import cx_Oracle as Database +except ImportError as e: + from django.core.exceptions import ImproperlyConfigured + raise ImproperlyConfigured("Error loading cx_Oracle module: %s" % e) + +try: + import pytz +except ImportError: + pytz = None + +from django.db import utils +from django.db.backends import * +from django.db.backends.oracle.client import DatabaseClient +from django.db.backends.oracle.creation import DatabaseCreation +from django.db.backends.oracle.introspection import DatabaseIntrospection +from django.utils.encoding import force_bytes, force_text + + +DatabaseError = Database.DatabaseError +IntegrityError = Database.IntegrityError + +# Check whether cx_Oracle was compiled with the WITH_UNICODE option if cx_Oracle is pre-5.1. This will +# also be True for cx_Oracle 5.1 and in Python 3.0. See #19606 +if int(Database.version.split('.', 1)[0]) >= 5 and \ + (int(Database.version.split('.', 2)[1]) >= 1 or + not hasattr(Database, 'UNICODE')): + convert_unicode = force_text +else: + convert_unicode = force_bytes + + +class DatabaseFeatures(BaseDatabaseFeatures): + empty_fetchmany_value = () + needs_datetime_string_cast = False + interprets_empty_strings_as_nulls = True + uses_savepoints = True + has_select_for_update = True + has_select_for_update_nowait = True + can_return_id_from_insert = True + allow_sliced_subqueries = False + supports_subqueries_in_group_by = False + supports_transactions = True + supports_timezones = False + has_zoneinfo_database = pytz is not None + supports_bitwise_or = False + can_defer_constraint_checks = True + ignores_nulls_in_unique_constraints = False + has_bulk_insert = True + supports_tablespaces = True + supports_sequence_reset = False + atomic_transactions = False + +class DatabaseOperations(BaseDatabaseOperations): + compiler_module = "django.db.backends.oracle.compiler" + + def autoinc_sql(self, table, column): + # To simulate auto-incrementing primary keys in Oracle, we have to + # create a sequence and a trigger. + sq_name = self._get_sequence_name(table) + tr_name = self._get_trigger_name(table) + tbl_name = self.quote_name(table) + col_name = self.quote_name(column) + sequence_sql = """ +DECLARE + i INTEGER; +BEGIN + SELECT COUNT(*) INTO i FROM USER_CATALOG + WHERE TABLE_NAME = '%(sq_name)s' AND TABLE_TYPE = 'SEQUENCE'; + IF i = 0 THEN + EXECUTE IMMEDIATE 'CREATE SEQUENCE "%(sq_name)s"'; + END IF; +END; +/""" % locals() + trigger_sql = """ +CREATE OR REPLACE TRIGGER "%(tr_name)s" +BEFORE INSERT ON %(tbl_name)s +FOR EACH ROW +WHEN (new.%(col_name)s IS NULL) + BEGIN + SELECT "%(sq_name)s".nextval + INTO :new.%(col_name)s FROM dual; + END; +/""" % locals() + return sequence_sql, trigger_sql + + def cache_key_culling_sql(self): + return """ + SELECT cache_key + FROM (SELECT cache_key, rank() OVER (ORDER BY cache_key) AS rank FROM %s) + WHERE rank = %%s + 1 + """ + + def date_extract_sql(self, lookup_type, field_name): + if lookup_type == 'week_day': + # TO_CHAR(field, 'D') returns an integer from 1-7, where 1=Sunday. + return "TO_CHAR(%s, 'D')" % field_name + else: + # http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions050.htm + return "EXTRACT(%s FROM %s)" % (lookup_type.upper(), field_name) + + def date_interval_sql(self, sql, connector, timedelta): + """ + Implements the interval functionality for expressions + format for Oracle: + (datefield + INTERVAL '3 00:03:20.000000' DAY(1) TO SECOND(6)) + """ + minutes, seconds = divmod(timedelta.seconds, 60) + hours, minutes = divmod(minutes, 60) + days = str(timedelta.days) + day_precision = len(days) + fmt = "(%s %s INTERVAL '%s %02d:%02d:%02d.%06d' DAY(%d) TO SECOND(6))" + return fmt % (sql, connector, days, hours, minutes, seconds, + timedelta.microseconds, day_precision) + + def date_trunc_sql(self, lookup_type, field_name): + # http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions230.htm#i1002084 + if lookup_type in ('year', 'month'): + return "TRUNC(%s, '%s')" % (field_name, lookup_type.upper()) + else: + return "TRUNC(%s)" % field_name + + # Oracle crashes with "ORA-03113: end-of-file on communication channel" + # if the time zone name is passed in parameter. Use interpolation instead. + # https://groups.google.com/forum/#!msg/django-developers/zwQju7hbG78/9l934yelwfsJ + # This regexp matches all time zone names from the zoneinfo database. + _tzname_re = re.compile(r'^[\w/:+-]+$') + + def _convert_field_to_tz(self, field_name, tzname): + if not self._tzname_re.match(tzname): + raise ValueError("Invalid time zone name: %s" % tzname) + # Convert from UTC to local time, returning TIMESTAMP WITH TIME ZONE. + result = "(FROM_TZ(%s, '0:00') AT TIME ZONE '%s')" % (field_name, tzname) + # Extracting from a TIMESTAMP WITH TIME ZONE ignore the time zone. + # Convert to a DATETIME, which is called DATE by Oracle. There's no + # built-in function to do that; the easiest is to go through a string. + result = "TO_CHAR(%s, 'YYYY-MM-DD HH24:MI:SS')" % result + result = "TO_DATE(%s, 'YYYY-MM-DD HH24:MI:SS')" % result + # Re-convert to a TIMESTAMP because EXTRACT only handles the date part + # on DATE values, even though they actually store the time part. + return "CAST(%s AS TIMESTAMP)" % result + + def datetime_extract_sql(self, lookup_type, field_name, tzname): + if settings.USE_TZ: + field_name = self._convert_field_to_tz(field_name, tzname) + if lookup_type == 'week_day': + # TO_CHAR(field, 'D') returns an integer from 1-7, where 1=Sunday. + sql = "TO_CHAR(%s, 'D')" % field_name + else: + # http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions050.htm + sql = "EXTRACT(%s FROM %s)" % (lookup_type.upper(), field_name) + return sql, [] + + def datetime_trunc_sql(self, lookup_type, field_name, tzname): + if settings.USE_TZ: + field_name = self._convert_field_to_tz(field_name, tzname) + # http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions230.htm#i1002084 + if lookup_type in ('year', 'month'): + sql = "TRUNC(%s, '%s')" % (field_name, lookup_type.upper()) + elif lookup_type == 'day': + sql = "TRUNC(%s)" % field_name + elif lookup_type == 'hour': + sql = "TRUNC(%s, 'HH24')" % field_name + elif lookup_type == 'minute': + sql = "TRUNC(%s, 'MI')" % field_name + else: + sql = field_name # Cast to DATE removes sub-second precision. + return sql, [] + + def convert_values(self, value, field): + if isinstance(value, Database.LOB): + value = value.read() + if field and field.get_internal_type() == 'TextField': + value = force_text(value) + + # Oracle stores empty strings as null. We need to undo this in + # order to adhere to the Django convention of using the empty + # string instead of null, but only if the field accepts the + # empty string. + if value is None and field and field.empty_strings_allowed: + value = '' + # Convert 1 or 0 to True or False + elif value in (1, 0) and field and field.get_internal_type() in ('BooleanField', 'NullBooleanField'): + value = bool(value) + # Force floats to the correct type + elif value is not None and field and field.get_internal_type() == 'FloatField': + value = float(value) + # Convert floats to decimals + elif value is not None and field and field.get_internal_type() == 'DecimalField': + value = util.typecast_decimal(field.format_number(value)) + # cx_Oracle always returns datetime.datetime objects for + # DATE and TIMESTAMP columns, but Django wants to see a + # python datetime.date, .time, or .datetime. We use the type + # of the Field to determine which to cast to, but it's not + # always available. + # As a workaround, we cast to date if all the time-related + # values are 0, or to time if the date is 1/1/1900. + # This could be cleaned a bit by adding a method to the Field + # classes to normalize values from the database (the to_python + # method is used for validation and isn't what we want here). + elif isinstance(value, Database.Timestamp): + if field and field.get_internal_type() == 'DateTimeField': + pass + elif field and field.get_internal_type() == 'DateField': + value = value.date() + elif field and field.get_internal_type() == 'TimeField' or (value.year == 1900 and value.month == value.day == 1): + value = value.time() + elif value.hour == value.minute == value.second == value.microsecond == 0: + value = value.date() + return value + + def deferrable_sql(self): + return " DEFERRABLE INITIALLY DEFERRED" + + def drop_sequence_sql(self, table): + return "DROP SEQUENCE %s;" % self.quote_name(self._get_sequence_name(table)) + + def fetch_returned_insert_id(self, cursor): + return int(cursor._insert_id_var.getvalue()) + + def field_cast_sql(self, db_type, internal_type): + if db_type and db_type.endswith('LOB'): + return "DBMS_LOB.SUBSTR(%s)" + else: + return "%s" + + def last_executed_query(self, cursor, sql, params): + # http://cx-oracle.sourceforge.net/html/cursor.html#Cursor.statement + # The DB API definition does not define this attribute. + statement = cursor.statement + if statement and six.PY2 and not isinstance(statement, unicode): + statement = statement.decode('utf-8') + # Unlike Psycopg's `query` and MySQLdb`'s `_last_executed`, CxOracle's + # `statement` doesn't contain the query parameters. refs #20010. + return super(DatabaseOperations, self).last_executed_query(cursor, statement, params) + + def last_insert_id(self, cursor, table_name, pk_name): + sq_name = self._get_sequence_name(table_name) + cursor.execute('SELECT "%s".currval FROM dual' % sq_name) + return cursor.fetchone()[0] + + def lookup_cast(self, lookup_type): + if lookup_type in ('iexact', 'icontains', 'istartswith', 'iendswith'): + return "UPPER(%s)" + return "%s" + + def max_in_list_size(self): + return 1000 + + def max_name_length(self): + return 30 + + def prep_for_iexact_query(self, x): + return x + + def process_clob(self, value): + if value is None: + return '' + return force_text(value.read()) + + def quote_name(self, name): + # SQL92 requires delimited (quoted) names to be case-sensitive. When + # not quoted, Oracle has case-insensitive behavior for identifiers, but + # always defaults to uppercase. + # We simplify things by making Oracle identifiers always uppercase. + if not name.startswith('"') and not name.endswith('"'): + name = '"%s"' % util.truncate_name(name.upper(), + self.max_name_length()) + # Oracle puts the query text into a (query % args) construct, so % signs + # in names need to be escaped. The '%%' will be collapsed back to '%' at + # that stage so we aren't really making the name longer here. + name = name.replace('%','%%') + return name.upper() + + def random_function_sql(self): + return "DBMS_RANDOM.RANDOM" + + def regex_lookup_9(self, lookup_type): + raise NotImplementedError("Regexes are not supported in Oracle before version 10g.") + + def regex_lookup_10(self, lookup_type): + if lookup_type == 'regex': + match_option = "'c'" + else: + match_option = "'i'" + return 'REGEXP_LIKE(%%s, %%s, %s)' % match_option + + def regex_lookup(self, lookup_type): + # If regex_lookup is called before it's been initialized, then create + # a cursor to initialize it and recur. + self.connection.cursor() + return self.connection.ops.regex_lookup(lookup_type) + + def return_insert_id(self): + return "RETURNING %s INTO %%s", (InsertIdVar(),) + + def savepoint_create_sql(self, sid): + return convert_unicode("SAVEPOINT " + self.quote_name(sid)) + + def savepoint_rollback_sql(self, sid): + return convert_unicode("ROLLBACK TO SAVEPOINT " + self.quote_name(sid)) + + def sql_flush(self, style, tables, sequences, allow_cascade=False): + # Return a list of 'TRUNCATE x;', 'TRUNCATE y;', + # 'TRUNCATE z;'... style SQL statements + if tables: + # Oracle does support TRUNCATE, but it seems to get us into + # FK referential trouble, whereas DELETE FROM table works. + sql = ['%s %s %s;' % ( + style.SQL_KEYWORD('DELETE'), + style.SQL_KEYWORD('FROM'), + style.SQL_FIELD(self.quote_name(table)) + ) for table in tables] + # Since we've just deleted all the rows, running our sequence + # ALTER code will reset the sequence to 0. + sql.extend(self.sequence_reset_by_name_sql(style, sequences)) + return sql + else: + return [] + + def sequence_reset_by_name_sql(self, style, sequences): + sql = [] + for sequence_info in sequences: + sequence_name = self._get_sequence_name(sequence_info['table']) + table_name = self.quote_name(sequence_info['table']) + column_name = self.quote_name(sequence_info['column'] or 'id') + query = _get_sequence_reset_sql() % {'sequence': sequence_name, + 'table': table_name, + 'column': column_name} + sql.append(query) + return sql + + def sequence_reset_sql(self, style, model_list): + from django.db import models + output = [] + query = _get_sequence_reset_sql() + for model in model_list: + for f in model._meta.local_fields: + if isinstance(f, models.AutoField): + table_name = self.quote_name(model._meta.db_table) + sequence_name = self._get_sequence_name(model._meta.db_table) + column_name = self.quote_name(f.column) + output.append(query % {'sequence': sequence_name, + 'table': table_name, + 'column': column_name}) + # Only one AutoField is allowed per model, so don't + # continue to loop + break + for f in model._meta.many_to_many: + if not f.rel.through: + table_name = self.quote_name(f.m2m_db_table()) + sequence_name = self._get_sequence_name(f.m2m_db_table()) + column_name = self.quote_name('id') + output.append(query % {'sequence': sequence_name, + 'table': table_name, + 'column': column_name}) + return output + + def start_transaction_sql(self): + return '' + + def tablespace_sql(self, tablespace, inline=False): + if inline: + return "USING INDEX TABLESPACE %s" % self.quote_name(tablespace) + else: + return "TABLESPACE %s" % self.quote_name(tablespace) + + def value_to_db_datetime(self, value): + if value is None: + return None + + # Oracle doesn't support tz-aware datetimes + if timezone.is_aware(value): + if settings.USE_TZ: + value = value.astimezone(timezone.utc).replace(tzinfo=None) + else: + raise ValueError("Oracle backend does not support timezone-aware datetimes when USE_TZ is False.") + + return six.text_type(value) + + def value_to_db_time(self, value): + if value is None: + return None + + if isinstance(value, six.string_types): + return datetime.datetime.strptime(value, '%H:%M:%S') + + # Oracle doesn't support tz-aware times + if timezone.is_aware(value): + raise ValueError("Oracle backend does not support timezone-aware times.") + + return datetime.datetime(1900, 1, 1, value.hour, value.minute, + value.second, value.microsecond) + + def year_lookup_bounds_for_date_field(self, value): + first = '%s-01-01' + second = '%s-12-31' + return [first % value, second % value] + + def year_lookup_bounds_for_datetime_field(self, value): + # The default implementation uses datetime objects for the bounds. + # This must be overridden here, to use a formatted date (string) as + # 'second' instead -- cx_Oracle chops the fraction-of-second part + # off of datetime objects, leaving almost an entire second out of + # the year under the default implementation. + bounds = super(DatabaseOperations, self).year_lookup_bounds_for_datetime_field(value) + if settings.USE_TZ: + bounds = [b.astimezone(timezone.utc).replace(tzinfo=None) for b in bounds] + return [b.isoformat(b' ') for b in bounds] + + def combine_expression(self, connector, sub_expressions): + "Oracle requires special cases for %% and & operators in query expressions" + if connector == '%%': + return 'MOD(%s)' % ','.join(sub_expressions) + elif connector == '&': + return 'BITAND(%s)' % ','.join(sub_expressions) + elif connector == '|': + raise NotImplementedError("Bit-wise or is not supported in Oracle.") + return super(DatabaseOperations, self).combine_expression(connector, sub_expressions) + + def _get_sequence_name(self, table): + name_length = self.max_name_length() - 3 + return '%s_SQ' % util.truncate_name(table, name_length).upper() + + def _get_trigger_name(self, table): + name_length = self.max_name_length() - 3 + return '%s_TR' % util.truncate_name(table, name_length).upper() + + def bulk_insert_sql(self, fields, num_values): + items_sql = "SELECT %s FROM DUAL" % ", ".join(["%s"] * len(fields)) + return " UNION ALL ".join([items_sql] * num_values) + + +class _UninitializedOperatorsDescriptor(object): + + def __get__(self, instance, owner): + # If connection.operators is looked up before a connection has been + # created, transparently initialize connection.operators to avert an + # AttributeError. + if instance is None: + raise AttributeError("operators not available as class attribute") + # Creating a cursor will initialize the operators. + instance.cursor().close() + return instance.__dict__['operators'] + + +class DatabaseWrapper(BaseDatabaseWrapper): + vendor = 'oracle' + operators = _UninitializedOperatorsDescriptor() + + _standard_operators = { + 'exact': '= %s', + 'iexact': '= UPPER(%s)', + 'contains': "LIKE TRANSLATE(%s USING NCHAR_CS) ESCAPE TRANSLATE('\\' USING NCHAR_CS)", + 'icontains': "LIKE UPPER(TRANSLATE(%s USING NCHAR_CS)) ESCAPE TRANSLATE('\\' USING NCHAR_CS)", + 'gt': '> %s', + 'gte': '>= %s', + 'lt': '< %s', + 'lte': '<= %s', + 'startswith': "LIKE TRANSLATE(%s USING NCHAR_CS) ESCAPE TRANSLATE('\\' USING NCHAR_CS)", + 'endswith': "LIKE TRANSLATE(%s USING NCHAR_CS) ESCAPE TRANSLATE('\\' USING NCHAR_CS)", + 'istartswith': "LIKE UPPER(TRANSLATE(%s USING NCHAR_CS)) ESCAPE TRANSLATE('\\' USING NCHAR_CS)", + 'iendswith': "LIKE UPPER(TRANSLATE(%s USING NCHAR_CS)) ESCAPE TRANSLATE('\\' USING NCHAR_CS)", + } + + _likec_operators = _standard_operators.copy() + _likec_operators.update({ + 'contains': "LIKEC %s ESCAPE '\\'", + 'icontains': "LIKEC UPPER(%s) ESCAPE '\\'", + 'startswith': "LIKEC %s ESCAPE '\\'", + 'endswith': "LIKEC %s ESCAPE '\\'", + 'istartswith': "LIKEC UPPER(%s) ESCAPE '\\'", + 'iendswith': "LIKEC UPPER(%s) ESCAPE '\\'", + }) + + Database = Database + + def __init__(self, *args, **kwargs): + super(DatabaseWrapper, self).__init__(*args, **kwargs) + + self.features = DatabaseFeatures(self) + use_returning_into = self.settings_dict["OPTIONS"].get('use_returning_into', True) + self.features.can_return_id_from_insert = use_returning_into + self.ops = DatabaseOperations(self) + self.client = DatabaseClient(self) + self.creation = DatabaseCreation(self) + self.introspection = DatabaseIntrospection(self) + self.validation = BaseDatabaseValidation(self) + + def _connect_string(self): + settings_dict = self.settings_dict + if not settings_dict['HOST'].strip(): + settings_dict['HOST'] = 'localhost' + if settings_dict['PORT'].strip(): + dsn = Database.makedsn(settings_dict['HOST'], + int(settings_dict['PORT']), + settings_dict['NAME']) + else: + dsn = settings_dict['NAME'] + return "%s/%s@%s" % (settings_dict['USER'], + settings_dict['PASSWORD'], dsn) + + def get_connection_params(self): + conn_params = self.settings_dict['OPTIONS'].copy() + if 'use_returning_into' in conn_params: + del conn_params['use_returning_into'] + return conn_params + + def get_new_connection(self, conn_params): + conn_string = convert_unicode(self._connect_string()) + return Database.connect(conn_string, **conn_params) + + def init_connection_state(self): + cursor = self.create_cursor() + # Set the territory first. The territory overrides NLS_DATE_FORMAT + # and NLS_TIMESTAMP_FORMAT to the territory default. When all of + # these are set in single statement it isn't clear what is supposed + # to happen. + cursor.execute("ALTER SESSION SET NLS_TERRITORY = 'AMERICA'") + # Set oracle date to ansi date format. This only needs to execute + # once when we create a new connection. We also set the Territory + # to 'AMERICA' which forces Sunday to evaluate to a '1' in + # TO_CHAR(). + cursor.execute( + "ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS'" + " NLS_TIMESTAMP_FORMAT = 'YYYY-MM-DD HH24:MI:SS.FF'" + + (" TIME_ZONE = 'UTC'" if settings.USE_TZ else '')) + cursor.close() + if 'operators' not in self.__dict__: + # Ticket #14149: Check whether our LIKE implementation will + # work for this connection or we need to fall back on LIKEC. + # This check is performed only once per DatabaseWrapper + # instance per thread, since subsequent connections will use + # the same settings. + cursor = self.create_cursor() + try: + cursor.execute("SELECT 1 FROM DUAL WHERE DUMMY %s" + % self._standard_operators['contains'], + ['X']) + except DatabaseError: + self.operators = self._likec_operators + else: + self.operators = self._standard_operators + cursor.close() + + # There's no way for the DatabaseOperations class to know the + # currently active Oracle version, so we do some setups here. + # TODO: Multi-db support will need a better solution (a way to + # communicate the current version). + if self.oracle_version is not None and self.oracle_version <= 9: + self.ops.regex_lookup = self.ops.regex_lookup_9 + else: + self.ops.regex_lookup = self.ops.regex_lookup_10 + + try: + self.connection.stmtcachesize = 20 + except: + # Django docs specify cx_Oracle version 4.3.1 or higher, but + # stmtcachesize is available only in 4.3.2 and up. + pass + + def create_cursor(self): + return FormatStylePlaceholderCursor(self.connection) + + def _commit(self): + if self.connection is not None: + try: + return self.connection.commit() + except Database.DatabaseError as e: + # cx_Oracle 5.0.4 raises a cx_Oracle.DatabaseError exception + # with the following attributes and values: + # code = 2091 + # message = 'ORA-02091: transaction rolled back + # 'ORA-02291: integrity constraint (TEST_DJANGOTEST.SYS + # _C00102056) violated - parent key not found' + # We convert that particular case to our IntegrityError exception + x = e.args[0] + if hasattr(x, 'code') and hasattr(x, 'message') \ + and x.code == 2091 and 'ORA-02291' in x.message: + six.reraise(utils.IntegrityError, utils.IntegrityError(*tuple(e.args)), sys.exc_info()[2]) + raise + + # Oracle doesn't support savepoint commits. Ignore them. + def _savepoint_commit(self, sid): + pass + + def _set_autocommit(self, autocommit): + with self.wrap_database_errors: + self.connection.autocommit = autocommit + + def check_constraints(self, table_names=None): + """ + To check constraints, we set constraints to immediate. Then, when, we're done we must ensure they + are returned to deferred. + """ + self.cursor().execute('SET CONSTRAINTS ALL IMMEDIATE') + self.cursor().execute('SET CONSTRAINTS ALL DEFERRED') + + def is_usable(self): + try: + if hasattr(self.connection, 'ping'): # Oracle 10g R2 and higher + self.connection.ping() + else: + # Use a cx_Oracle cursor directly, bypassing Django's utilities. + self.connection.cursor().execute("SELECT 1 FROM DUAL") + except Database.Error: + return False + else: + return True + + @cached_property + def oracle_version(self): + with self.temporary_connection(): + version = self.connection.version + try: + return int(version.split('.')[0]) + except ValueError: + return None + + +class OracleParam(object): + """ + Wrapper object for formatting parameters for Oracle. If the string + representation of the value is large enough (greater than 4000 characters) + the input size needs to be set as CLOB. Alternatively, if the parameter + has an `input_size` attribute, then the value of the `input_size` attribute + will be used instead. Otherwise, no input size will be set for the + parameter when executing the query. + """ + + 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): + if timezone.is_naive(param): + warnings.warn("Oracle received a naive datetime (%s)" + " while time zone support is active." % param, + RuntimeWarning) + default_timezone = timezone.get_default_timezone() + param = timezone.make_aware(param, default_timezone) + param = param.astimezone(timezone.utc).replace(tzinfo=None) + + # Oracle doesn't recognize True and False correctly in Python 3. + # The conversion done below works both in 2 and 3. + if param is True: + param = "1" + elif param is False: + param = "0" + if hasattr(param, 'bind_parameter'): + self.force_bytes = param.bind_parameter(cursor) + elif isinstance(param, six.memoryview): + self.force_bytes = param + else: + self.force_bytes = convert_unicode(param, cursor.charset, + strings_only) + if hasattr(param, 'input_size'): + # If parameter has `input_size` attribute, use that. + self.input_size = param.input_size + elif isinstance(param, six.string_types) and len(param) > 4000: + # Mark any string param greater than 4000 characters as a CLOB. + self.input_size = Database.CLOB + else: + self.input_size = None + + +class VariableWrapper(object): + """ + An adapter class for cursor variables that prevents the wrapped object + from being converted into a string when used to instanciate an OracleParam. + 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 InsertIdVar(object): + """ + A late-binding cursor variable that can be passed to Cursor.execute + as a parameter, in order to receive the id of the row created by an + insert statement. + """ + + def bind_parameter(self, cursor): + param = cursor.cursor.var(Database.NUMBER) + cursor._insert_id_var = param + return param + + +class FormatStylePlaceholderCursor(object): + """ + 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() + # Necessary to retrieve decimal values without rounding error. + self.cursor.numbersAsStrings = True + # Default arraysize of 1 is highly sub-optimal. + self.cursor.arraysize = 100 + + def _format_params(self, params): + try: + return dict((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 dict((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): + # 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 = [] + query = convert_unicode(query, self.charset) + elif hasattr(params, 'keys'): + # Handle params as dict + args = dict((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 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) + # datetimes are returned as TIMESTAMP, except the results + # of "dates" queries, which are returned as DATETIME. + elif desc[1] in (Database.TIMESTAMP, Database.DATETIME): + # Confirm that dt is naive before overwriting its tzinfo. + if settings.USE_TZ and value is not None and timezone.is_naive(value): + value = value.replace(tzinfo=timezone.utc) + 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 + + +def _get_sequence_reset_sql(): + # TODO: colorize this SQL code with style.SQL_KEYWORD(), etc. + return """ +DECLARE + table_value integer; + seq_value integer; +BEGIN + SELECT NVL(MAX(%(column)s), 0) INTO table_value FROM %(table)s; + SELECT NVL(last_number - cache_size, 0) INTO seq_value FROM user_sequences + WHERE sequence_name = '%(sequence)s'; + WHILE table_value > seq_value LOOP + SELECT "%(sequence)s".nextval INTO seq_value FROM dual; + END LOOP; +END; +/""" |