python/lib/django-0.96/django/db/backends/oracle/base.py

   1 """
   2 Oracle database backend for Django.
   3
   4 Requires cx_Oracle: http://www.python.net/crew/atuining/cx_Oracle/
   5 """
   6
   7 from django.db.backends import util
   8 try:
   9     import cx_Oracle as Database
  10 except ImportError, e:
  11     from django.core.exceptions import ImproperlyConfigured
  12     raise ImproperlyConfigured, "Error loading cx_Oracle module: %s" % e
  13
  14 DatabaseError = Database.Error
  15
  16 try:
  17     # Only exists in Python 2.4+
  18     from threading import local
  19 except ImportError:
  20     # Import copy of _thread_local.py from Python 2.4
  21     from django.utils._threading_local import local
  22
  23 class DatabaseWrapper(local):
  24     def __init__(self, **kwargs):
  25         self.connection = None
  26         self.queries = []
  27         self.options = kwargs
  28
  29     def _valid_connection(self):
  30         return self.connection is not None
  31
  32     def cursor(self):
  33         from django.conf import settings
  34         if not self._valid_connection():
  35             if len(settings.DATABASE_HOST.strip()) == 0:
  36                 settings.DATABASE_HOST = 'localhost'
  37             if len(settings.DATABASE_PORT.strip()) != 0:
  38                 dsn = Database.makedsn(settings.DATABASE_HOST, int(settings.DATABASE_PORT), settings.DATABASE_NAME)
  39                 self.connection = Database.connect(settings.DATABASE_USER, settings.DATABASE_PASSWORD, dsn, **self.options)
  40             else:
  41                 conn_string = "%s/%s@%s" % (settings.DATABASE_USER, settings.DATABASE_PASSWORD, settings.DATABASE_NAME)
  42                 self.connection = Database.connect(conn_string, **self.options)
  43         return FormatStylePlaceholderCursor(self.connection)
  44
  45     def _commit(self):
  46         if self.connection is not None:
  47             self.connection.commit()
  48
  49     def _rollback(self):
  50         if self.connection is not None:
  51             try:
  52                 self.connection.rollback()
  53             except Database.NotSupportedError:
  54                 pass
  55
  56     def close(self):
  57         if self.connection is not None:
  58             self.connection.close()
  59             self.connection = None
  60
  61 supports_constraints = True
  62
  63 class FormatStylePlaceholderCursor(Database.Cursor):
  64     """
  65     Django uses "format" (e.g. '%s') style placeholders, but Oracle uses ":var" style.
  66     This fixes it -- but note that if you want to use a literal "%s" in a query,
  67     you'll need to use "%%s".
  68     """
  69     def execute(self, query, params=None):
  70         if params is None: params = []
  71         query = self.convert_arguments(query, len(params))
  72         return Database.Cursor.execute(self, query, params)
  73
  74     def executemany(self, query, params=None):
  75         if params is None: params = []
  76         query = self.convert_arguments(query, len(params[0]))
  77         return Database.Cursor.executemany(self, query, params)
  78
  79     def convert_arguments(self, query, num_params):
  80         # replace occurances of "%s" with ":arg" - Oracle requires colons for parameter placeholders.
  81         args = [':arg' for i in range(num_params)]
  82         return query % tuple(args)
  83
  84 def quote_name(name):
  85     return name
  86
  87 dictfetchone = util.dictfetchone
  88 dictfetchmany = util.dictfetchmany
  89 dictfetchall  = util.dictfetchall
  90
  91 def get_last_insert_id(cursor, table_name, pk_name):
  92     query = "SELECT %s_sq.currval from dual" % table_name
  93     cursor.execute(query)
  94     return cursor.fetchone()[0]
  95
  96 def get_date_extract_sql(lookup_type, table_name):
  97     # lookup_type is 'year', 'month', 'day'
  98     # http://www.psoug.org/reference/date_func.html
  99     return "EXTRACT(%s FROM %s)" % (lookup_type, table_name)
 100
 101 def get_date_trunc_sql(lookup_type, field_name):
 102     return "EXTRACT(%s FROM TRUNC(%s))" % (lookup_type, field_name)
 103
 104 def get_limit_offset_sql(limit, offset=None):
 105     # Limits and offset are too complicated to be handled here.
 106     # Instead, they are handled in django/db/query.py.
 107     pass
 108
 109 def get_random_function_sql():
 110     return "DBMS_RANDOM.RANDOM"
 111
 112 def get_deferrable_sql():
 113     return " DEFERRABLE INITIALLY DEFERRED"
 114
 115 def get_fulltext_search_sql(field_name):
 116     raise NotImplementedError
 117
 118 def get_drop_foreignkey_sql():
 119     return "DROP FOREIGN KEY"
 120
 121 def get_pk_default_value():
 122     return "DEFAULT"
 123
 124 def get_sql_flush(style, tables, sequences):
 125     """Return a list of SQL statements required to remove all data from
 126     all tables in the database (without actually removing the tables
 127     themselves) and put the database in an empty 'initial' state
 128     """
 129     # Return a list of 'TRUNCATE x;', 'TRUNCATE y;', 'TRUNCATE z;'... style SQL statements
 130     # TODO - SQL not actually tested against Oracle yet!
 131     # TODO - autoincrement indices reset required? See other get_sql_flush() implementations
 132     sql = ['%s %s;' % \
 133             (style.SQL_KEYWORD('TRUNCATE'),
 134              style.SQL_FIELD(quote_name(table))
 135              )  for table in tables]
 136
 137
 138 OPERATOR_MAPPING = {
 139     'exact': '= %s',
 140     'iexact': 'LIKE %s',
 141     'contains': 'LIKE %s',
 142     'icontains': 'LIKE %s',
 143     'gt': '> %s',
 144     'gte': '>= %s',
 145     'lt': '< %s',
 146     'lte': '<= %s',
 147     'startswith': 'LIKE %s',
 148     'endswith': 'LIKE %s',
 149     'istartswith': 'LIKE %s',
 150     'iendswith': 'LIKE %s',
 151 }