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Diffstat (limited to 'webapp/django/db/backends/oracle/base.py')
| -rw-r--r-- | webapp/django/db/backends/oracle/base.py | 425 |
1 files changed, 425 insertions, 0 deletions
diff --git a/webapp/django/db/backends/oracle/base.py b/webapp/django/db/backends/oracle/base.py new file mode 100644 index 0000000000..b8bc6d00d5 --- /dev/null +++ b/webapp/django/db/backends/oracle/base.py @@ -0,0 +1,425 @@ +""" +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() |