"""
Oracle database backend for Django.
Requires cx_Oracle: http://cx-oracle.sourceforge.net/
"""
import datetime
import os
import sys
import time
from decimal import Decimal
# Oracle takes client-side character set encoding from the environment.
os.environ['NLS_LANG'] = '.UTF8'
# This prevents unicode from getting mangled by getting encoded into the
# potentially non-unicode database character set.
os.environ['ORA_NCHAR_LITERAL_REPLACE'] = 'TRUE'
try:
import cx_Oracle as Database
except ImportError, e:
from django.core.exceptions import ImproperlyConfigured
raise ImproperlyConfigured("Error loading cx_Oracle module: %s" % e)
from django.db import utils
from django.db.backends import *
from django.db.backends.signals import connection_created
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 smart_str,force_unicode
DatabaseError = Database.DatabaseError
IntegrityError = Database.IntegrityError
# Check whether cx_Oracle was compiled with the WITH_UNICODE option. This will
# also be True in Python 3.0.
if int(Database.version.split('.', 1)[0]) >= 5 and not hasattr(Database, 'UNICODE'):
convert_unicode = force_unicode
else:
convert_unicode = smart_str
class DatabaseFeatures(BaseDatabaseFeatures):
empty_fetchmany_value = ()
needs_datetime_string_cast = False
interprets_empty_strings_as_nulls = True
uses_savepoints = True
can_return_id_from_insert = True
allow_sliced_subqueries = 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 = get_sequence_name(table)
tr_name = 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 date_extract_sql(self, lookup_type, field_name):
# http://download-east.oracle.com/docs/cd/B10501_01/server.920/a96540/functions42a.htm#1017163
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:
return "EXTRACT(%s FROM %s)" % (lookup_type, field_name)
def date_trunc_sql(self, lookup_type, field_name):
# Oracle uses TRUNC() for both dates and numbers.
# http://download-east.oracle.com/docs/cd/B10501_01/server.920/a96540/functions155a.htm#SQLRF06151
if lookup_type == 'day':
sql = 'TRUNC(%s)' % field_name
else:
sql = "TRUNC(%s, '%s')" % (field_name, lookup_type)
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_unicode(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 = u''
# 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):
# In Python 2.3, the cx_Oracle driver returns its own
# Timestamp object that we must convert to a datetime class.
if not isinstance(value, datetime.datetime):
value = datetime.datetime(value.year, value.month,
value.day, value.hour, value.minute, value.second,
value.fsecond)
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 datetime_cast_sql(self):
return "TO_TIMESTAMP(%s, 'YYYY-MM-DD HH24:MI:SS.FF')"
def deferrable_sql(self):
return " DEFERRABLE INITIALLY DEFERRED"
def drop_sequence_sql(self, table):
return "DROP SEQUENCE %s;" % self.quote_name(get_sequence_name(table))
def fetch_returned_insert_id(self, cursor):
return long(cursor._insert_id_var.getvalue())
def field_cast_sql(self, db_type):
if db_type and db_type.endswith('LOB'):
return "DBMS_LOB.SUBSTR(%s)"
else:
return "%s"
def last_insert_id(self, cursor, table_name, pk_name):
sq_name = 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_name_length(self):
return 30
def prep_for_iexact_query(self, x):
return x
def process_clob(self, value):
if value is None:
return u''
return force_unicode(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())
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.
from django.db import connection
connection.cursor()
return 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):
# 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.
for sequence_info in sequences:
sequence_name = 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
else:
return []
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 = 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 = 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):
return "%sTABLESPACE %s" % ((inline and "USING INDEX " or ""),
self.quote_name(tablespace))
def value_to_db_time(self, value):
if value is None:
return None
if isinstance(value, basestring):
return datetime.datetime(*(time.strptime(value, '%H:%M:%S')[:6]))
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 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)
class DatabaseWrapper(BaseDatabaseWrapper):
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)",
}
oracle_version = None
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
self.features = DatabaseFeatures()
self.ops = DatabaseOperations()
self.client = DatabaseClient(self)
self.creation = DatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = BaseDatabaseValidation(self)
def _valid_connection(self):
return self.connection is not None
def _connect_string(self):
settings_dict = self.settings_dict
if len(settings_dict['HOST'].strip()) == 0:
settings_dict['HOST'] = 'localhost'
if len(settings_dict['PORT'].strip()) != 0:
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 _cursor(self):
cursor = None
if not self._valid_connection():
conn_string = convert_unicode(self._connect_string())
self.connection = Database.connect(conn_string, **self.settings_dict['OPTIONS'])
cursor = FormatStylePlaceholderCursor(self.connection)
# 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' "
"NLS_TERRITORY = 'AMERICA'")
try:
self.oracle_version = int(self.connection.version.split('.')[0])
# 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 <= 9:
self.ops.regex_lookup = self.ops.regex_lookup_9
else:
self.ops.regex_lookup = self.ops.regex_lookup_10
except ValueError:
pass
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
connection_created.send(sender=self.__class__)
if not cursor:
cursor = FormatStylePlaceholderCursor(self.connection)
return cursor
# Oracle doesn't support savepoint commits. Ignore them.
def _savepoint_commit(self, sid):
pass
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):
if hasattr(param, 'bind_parameter'):
self.smart_str = param.bind_parameter(cursor)
else:
self.smart_str = 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, basestring) 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):
return tuple([OracleParam(p, self, True) for p in params])
def _guess_input_sizes(self, params_list):
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):
return [p.smart_str for p in params]
def execute(self, query, params=None):
if params is None:
params = []
else:
params = self._format_params(params)
args = [(':arg%d' % i) for i in range(len(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]
query = convert_unicode(query % tuple(args), self.charset)
self._guess_input_sizes([params])
try:
return self.cursor.execute(query, self._param_generator(params))
except Database.IntegrityError, e:
raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sys.exc_info()[2]
except Database.DatabaseError, 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):
raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sys.exc_info()[2]
raise utils.DatabaseError, utils.DatabaseError(*tuple(e)), sys.exc_info()[2]
def executemany(self, query, params=None):
try:
args = [(':arg%d' % i) for i in range(len(params[0]))]
except (IndexError, TypeError):
# No params given, nothing to do
return None
# 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]
query = convert_unicode(query % tuple(args), self.charset)
formatted = [self._format_params(i) for i in params]
self._guess_input_sizes(formatted)
try:
return self.cursor.executemany(query,
[self._param_generator(p) for p in formatted])
except Database.IntegrityError, e:
raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sys.exc_info()[2]
except Database.DatabaseError, 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):
raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sys.exc_info()[2]
raise utils.DatabaseError, utils.DatabaseError(*tuple(e)), sys.exc_info()[2]
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(object):
"""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(self.iter.next(), 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(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(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(value)
else:
value = int(value)
elif desc[1] in (Database.STRING, Database.FIXED_CHAR,
Database.LONG_STRING):
value = to_unicode(value)
casted.append(value)
return tuple(casted)
def to_unicode(s):
"""
Convert strings to Unicode objects (and return all other data types
unchanged).
"""
if isinstance(s, basestring):
return force_unicode(s)
return s
def _get_sequence_reset_sql():
# TODO: colorize this SQL code with style.SQL_KEYWORD(), etc.
return """
DECLARE
startvalue integer;
cval integer;
BEGIN
LOCK TABLE %(table)s IN SHARE MODE;
SELECT NVL(MAX(%(column)s), 0) INTO startvalue FROM %(table)s;
SELECT "%(sequence)s".nextval INTO cval FROM dual;
cval := startvalue - cval;
IF cval != 0 THEN
EXECUTE IMMEDIATE 'ALTER SEQUENCE "%(sequence)s" MINVALUE 0 INCREMENT BY '||cval;
SELECT "%(sequence)s".nextval INTO cval FROM dual;
EXECUTE IMMEDIATE 'ALTER SEQUENCE "%(sequence)s" INCREMENT BY 1';
END IF;
COMMIT;
END;
/"""
def get_sequence_name(table):
name_length = DatabaseOperations().max_name_length() - 3
return '%s_SQ' % util.truncate_name(table, name_length).upper()
def get_trigger_name(table):
name_length = DatabaseOperations().max_name_length() - 3
return '%s_TR' % util.truncate_name(table, name_length).upper()
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