369 lines
15 KiB
Python
369 lines
15 KiB
Python
"""
|
|
Oracle database backend for Django.
|
|
|
|
Requires cx_Oracle: http://www.python.net/crew/atuining/cx_Oracle/
|
|
"""
|
|
|
|
import os
|
|
|
|
from django.db.backends import BaseDatabaseWrapper, BaseDatabaseFeatures, BaseDatabaseOperations, util
|
|
from django.db.backends.oracle import query
|
|
from django.utils.datastructures import SortedDict
|
|
from django.utils.encoding import smart_str, force_unicode
|
|
|
|
# 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)
|
|
|
|
DatabaseError = Database.Error
|
|
IntegrityError = Database.IntegrityError
|
|
|
|
class DatabaseFeatures(BaseDatabaseFeatures):
|
|
allows_group_by_ordinal = False
|
|
empty_fetchmany_value = ()
|
|
needs_datetime_string_cast = False
|
|
supports_tablespaces = True
|
|
uses_case_insensitive_names = True
|
|
uses_custom_query_class = True
|
|
time_field_needs_date = True
|
|
interprets_empty_strings_as_nulls = True
|
|
date_field_supports_time_value = False
|
|
|
|
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 = 'CREATE SEQUENCE %s;' % sq_name
|
|
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 limit_offset_sql(self, limit, offset=None):
|
|
# Limits and offset are too complicated to be handled here.
|
|
# Instead, they are handled in django/db/backends/oracle/query.py.
|
|
return ""
|
|
|
|
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:
|
|
table_name = sequence_info['table']
|
|
seq_name = get_sequence_name(table_name)
|
|
column_name = self.quote_name(sequence_info['column'] or 'id')
|
|
query = _get_sequence_reset_sql() % {'sequence': seq_name,
|
|
'table': self.quote_name(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.fields:
|
|
if isinstance(f, models.AutoField):
|
|
sequence_name = get_sequence_name(model._meta.db_table)
|
|
column_name = self.quote_name(f.db_column or f.name)
|
|
output.append(query % {'sequence': sequence_name,
|
|
'table': model._meta.db_table,
|
|
'column': column_name})
|
|
break # Only one AutoField is allowed per model, so don't bother continuing.
|
|
for f in model._meta.many_to_many:
|
|
sequence_name = get_sequence_name(f.m2m_db_table())
|
|
output.append(query % {'sequence': sequence_name,
|
|
'table': f.m2m_db_table(),
|
|
'column': self.quote_name('id')})
|
|
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))
|
|
|
|
class DatabaseWrapper(BaseDatabaseWrapper):
|
|
features = DatabaseFeatures()
|
|
ops = DatabaseOperations()
|
|
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 _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 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 = {}
|
|
charset = self.charset
|
|
for key, value in params.items():
|
|
result[smart_str(key, charset)] = smart_str(value, charset)
|
|
return result
|
|
else:
|
|
return tuple([smart_str(p, self.charset, True) for p in params])
|
|
|
|
def _guess_input_sizes(self, params_list):
|
|
# Mark any string parameter greater than 4000 characters as an NCLOB.
|
|
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 isinstance(value, basestring) and len(value) > 4000:
|
|
sizes[key] = Database.NCLOB
|
|
if isinstance(sizes, dict):
|
|
self.setinputsizes(**sizes)
|
|
else:
|
|
self.setinputsizes(*sizes)
|
|
|
|
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, 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)
|
|
new_param_list = [self._format_params(i) for i in params]
|
|
self._guess_input_sizes(new_param_list)
|
|
return Database.Cursor.executemany(self, query, new_param_list)
|
|
|
|
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()
|