""" Oracle database backend for Django. Requires cx_Oracle: http://cx-oracle.sourceforge.net/ """ import os import datetime import time try: from decimal import Decimal except ImportError: from django.utils._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.backends import * from django.db.backends.signals import connection_created from django.db.backends.oracle import query 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 class DatabaseFeatures(BaseDatabaseFeatures): empty_fetchmany_value = () needs_datetime_string_cast = False uses_custom_query_class = True interprets_empty_strings_as_nulls = True uses_savepoints = True can_return_id_from_insert = True class DatabaseOperations(BaseDatabaseOperations): 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 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 query_class(self, DefaultQueryClass): return query.query_class(DefaultQueryClass, Database) 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 "SAVEPOINT " + self.quote_name(sid) def savepoint_rollback_sql(self, sid): return "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': "LIKEC %s ESCAPE '\\'", 'icontains': "LIKEC UPPER(%s) ESCAPE '\\'", 'gt': '> %s', 'gte': '>= %s', 'lt': '< %s', 'lte': '<= %s', 'startswith': "LIKEC %s ESCAPE '\\'", 'endswith': "LIKEC %s ESCAPE '\\'", 'istartswith': "LIKEC UPPER(%s) ESCAPE '\\'", 'iendswith': "LIKEC UPPER(%s) ESCAPE '\\'", } 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() def _valid_connection(self): return self.connection is not None def _connect_string(self): settings_dict = self.settings_dict if len(settings_dict['DATABASE_HOST'].strip()) == 0: settings_dict['DATABASE_HOST'] = 'localhost' if len(settings_dict['DATABASE_PORT'].strip()) != 0: dsn = Database.makedsn(settings_dict['DATABASE_HOST'], int(settings_dict['DATABASE_PORT']), settings_dict['DATABASE_NAME']) else: dsn = settings_dict['DATABASE_NAME'] return "%s/%s@%s" % (settings_dict['DATABASE_USER'], settings_dict['DATABASE_PASSWORD'], dsn) def _cursor(self): cursor = None if not self._valid_connection(): conn_string = self._connect_string() self.connection = Database.connect(conn_string, **self.settings_dict['DATABASE_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 NCLOB. 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 = smart_str(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 an CLOB. self.input_size = Database.CLOB else: self.input_size = None 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.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 = smart_str(query, self.charset) % tuple(args) self._guess_input_sizes([params]) try: return self.cursor.execute(query, self._param_generator(params)) except DatabaseError, e: # cx_Oracle <= 4.4.0 wrongly raises a DatabaseError for ORA-01400. if e.args[0].code == 1400 and not isinstance(e, IntegrityError): e = IntegrityError(e.args[0]) raise e 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 = smart_str(query, self.charset) % tuple(args) 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 DatabaseError, e: # cx_Oracle <= 4.4.0 wrongly raises a DatabaseError for ORA-01400. if e.args[0].code == 1400 and not isinstance(e, IntegrityError): e = IntegrityError(e.args[0]) raise e def fetchone(self): row = self.cursor.fetchone() if row is None: return row return self._rowfactory(row) def fetchmany(self, size=None): if size is None: size = self.arraysize return tuple([self._rowfactory(r) for r in self.cursor.fetchmany(size)]) def fetchall(self): return tuple([self._rowfactory(r) for r in self.cursor.fetchall()]) def _rowfactory(self, row): # 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, self.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 __getattr__(self, attr): if attr in self.__dict__: return self.__dict__[attr] else: return getattr(self.cursor, attr) def __iter__(self): return iter(self.cursor) 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()