| """ |
| Oracle database backend for Django. |
| |
| Requires cx_Oracle: http://www.python.net/crew/atuining/cx_Oracle/ |
| """ |
| |
| import os |
| import datetime |
| import time |
| |
| # Oracle takes client-side character set encoding from the environment. |
| os.environ['NLS_LANG'] = '.UTF8' |
| 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.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.Error |
| 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 |
| |
| |
| 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 |
| 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 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 = util.truncate_name(table_name, self.max_name_length() - 3) |
| cursor.execute('SELECT %s_sq.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 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 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}) |
| break # Only one AutoField is allowed per model, so don't bother continuing. |
| for f in model._meta.many_to_many: |
| 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] |
| |
| |
| 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.creation = DatabaseCreation(self) |
| self.introspection = DatabaseIntrospection(self) |
| self.validation = BaseDatabaseValidation() |
| |
| def _valid_connection(self): |
| return self.connection is not None |
| |
| def _cursor(self, settings): |
| cursor = None |
| if not self._valid_connection(): |
| if len(settings.DATABASE_HOST.strip()) == 0: |
| settings.DATABASE_HOST = 'localhost' |
| if len(settings.DATABASE_PORT.strip()) != 0: |
| dsn = Database.makedsn(settings.DATABASE_HOST, int(settings.DATABASE_PORT), settings.DATABASE_NAME) |
| self.connection = Database.connect(settings.DATABASE_USER, settings.DATABASE_PASSWORD, dsn, **self.options) |
| else: |
| conn_string = "%s/%s@%s" % (settings.DATABASE_USER, settings.DATABASE_PASSWORD, settings.DATABASE_NAME) |
| self.connection = Database.connect(conn_string, **self.options) |
| cursor = FormatStylePlaceholderCursor(self.connection) |
| # Set oracle date to ansi date format. This only needs to execute |
| # once when we create a new connection. |
| cursor.execute("ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD' " |
| "NLS_TIMESTAMP_FORMAT = 'YYYY-MM-DD HH24:MI:SS.FF'") |
| 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 |
| if not cursor: |
| cursor = FormatStylePlaceholderCursor(self.connection) |
| # Default arraysize of 1 is highly sub-optimal. |
| cursor.arraysize = 100 |
| return cursor |
| |
| |
| 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, charset, strings_only=False): |
| self.smart_str = smart_str(param, 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 parameter greater than 4000 characters as an NCLOB. |
| self.input_size = Database.NCLOB |
| else: |
| self.input_size = None |
| |
| |
| class FormatStylePlaceholderCursor(Database.Cursor): |
| """ |
| 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 _format_params(self, params): |
| if isinstance(params, dict): |
| result = {} |
| for key, value in params.items(): |
| result[smart_str(key, self.charset)] = OracleParam(param, self.charset) |
| return result |
| else: |
| return tuple([OracleParam(p, self.charset, True) for p in params]) |
| |
| def _guess_input_sizes(self, params_list): |
| if isinstance(params_list[0], dict): |
| sizes = {} |
| iterators = [params.iteritems() for params in params_list] |
| else: |
| sizes = [None] * len(params_list[0]) |
| iterators = [enumerate(params) for params in params_list] |
| for iterator in iterators: |
| for key, value in iterator: |
| if value.input_size: sizes[key] = value.input_size |
| if isinstance(sizes, dict): |
| self.setinputsizes(**sizes) |
| else: |
| self.setinputsizes(*sizes) |
| |
| def _param_generator(self, params): |
| if isinstance(params, dict): |
| return dict([(k, p.smart_str) for k, p in params.iteritems()]) |
| else: |
| 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]) |
| return Database.Cursor.execute(self, query, self._param_generator(params)) |
| |
| 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) |
| return Database.Cursor.executemany(self, query, [self._param_generator(p) for p in formatted]) |
| |
| def fetchone(self): |
| row = Database.Cursor.fetchone(self) |
| if row is None: |
| return row |
| return tuple([to_unicode(e) for e in row]) |
| |
| def fetchmany(self, size=None): |
| if size is None: |
| size = self.arraysize |
| return tuple([tuple([to_unicode(e) for e in r]) for r in Database.Cursor.fetchmany(self, size)]) |
| |
| def fetchall(self): |
| return tuple([tuple([to_unicode(e) for e in r]) for r in Database.Cursor.fetchall(self)]) |
| |
| 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() |
