per-object-permissions: Merged to trunk [5486] NOTE: Not fully tested, will be working on this over the next few weeks.

git-svn-id: http://code.djangoproject.com/svn/django/branches/per-object-permissions@5488 bcc190cf-cafb-0310-a4f2-bffc1f526a37

36 files changed, 1351 insertions, 514 deletions

diff --git a/django/db/__init__.py b/django/db/__init__.py
index 4176b5aa79..33223d200a 100644
--- a/django/db/__init__.py
+++ b/django/db/__init__.py
@@ -2,7 +2,7 @@ from django.conf import settings
 from django.core import signals
 from django.dispatch import dispatcher
 
-__all__ = ('backend', 'connection', 'DatabaseError')
+__all__ = ('backend', 'connection', 'DatabaseError', 'IntegrityError')
 
 if not settings.DATABASE_ENGINE:
     settings.DATABASE_ENGINE = 'dummy'
@@ -29,6 +29,7 @@ runshell = lambda: __import__('django.db.backends.%s.client' % settings.DATABASE
 
 connection = backend.DatabaseWrapper(**settings.DATABASE_OPTIONS)
 DatabaseError = backend.DatabaseError
+IntegrityError = backend.IntegrityError
 
 # Register an event that closes the database connection
 # when a Django request is finished.
diff --git a/django/db/backends/ado_mssql/base.py b/django/db/backends/ado_mssql/base.py
index 72d2fe083e..52363ed705 100644
--- a/django/db/backends/ado_mssql/base.py
+++ b/django/db/backends/ado_mssql/base.py
@@ -17,6 +17,7 @@ except ImportError:
     mx = None
 
 DatabaseError = Database.DatabaseError
+IntegrityError = Database.IntegrityError
 
 # We need to use a special Cursor class because adodbapi expects question-mark
 # param style, but Django expects "%s". This cursor converts question marks to
@@ -76,10 +77,11 @@ class DatabaseWrapper(local):
         return cursor
 
     def _commit(self):
-        return self.connection.commit()
+        if self.connection is not None:
+            return self.connection.commit()
 
     def _rollback(self):
-        if self.connection:
+        if self.connection is not None:
             return self.connection.rollback()
 
     def close(self):
@@ -125,6 +127,9 @@ def get_limit_offset_sql(limit, offset=None):
 def get_random_function_sql():
     return "RAND()"
 
+def get_deferrable_sql():
+    return " DEFERRABLE INITIALLY DEFERRED"
+
 def get_fulltext_search_sql(field_name):
     raise NotImplementedError
 
@@ -134,6 +139,24 @@ def get_drop_foreignkey_sql():
 def get_pk_default_value():
     return "DEFAULT"
 
+def get_sql_flush(style, tables, sequences):
+    """Return a list of SQL statements required to remove all data from
+    all tables in the database (without actually removing the tables
+    themselves) and put the database in an empty 'initial' state
+    """
+    # Return a list of 'TRUNCATE x;', 'TRUNCATE y;', 'TRUNCATE z;'... style SQL statements
+    # TODO - SQL not actually tested against ADO MSSQL yet!
+    # TODO - autoincrement indices reset required? See other get_sql_flush() implementations
+    sql_list = ['%s %s;' % \
+                (style.SQL_KEYWORD('TRUNCATE'),
+                 style.SQL_FIELD(quote_name(table))
+                 )  for table in tables]
+
+def get_sql_sequence_reset(style, model_list):
+    "Returns a list of the SQL statements to reset sequences for the given models."
+    # No sequence reset required
+    return []
+
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'LIKE %s',
diff --git a/django/db/backends/ado_mssql/creation.py b/django/db/backends/ado_mssql/creation.py
index 4d85d27ea5..a1098ea43e 100644
--- a/django/db/backends/ado_mssql/creation.py
+++ b/django/db/backends/ado_mssql/creation.py
@@ -5,9 +5,10 @@ DATA_TYPES = {
     'CommaSeparatedIntegerField': 'varchar(%(maxlength)s)',
     'DateField':         'smalldatetime',
     'DateTimeField':     'smalldatetime',
+    'DecimalField':      'numeric(%(max_digits)s, %(decimal_places)s)',
     'FileField':         'varchar(100)',
     'FilePathField':     'varchar(100)',
-    'FloatField':        'numeric(%(max_digits)s, %(decimal_places)s)',
+    'FloatField':        'double precision',
     'ImageField':        'varchar(100)',
     'IntegerField':      'int',
     'IPAddressField':    'char(15)',
@@ -21,6 +22,5 @@ DATA_TYPES = {
     'SmallIntegerField': 'smallint',
     'TextField':         'text',
     'TimeField':         'time',
-    'URLField':          'varchar(200)',
     'USStateField':      'varchar(2)',
 }
diff --git a/django/db/backends/dummy/base.py b/django/db/backends/dummy/base.py
index f98afc48bb..d0ec897407 100644
--- a/django/db/backends/dummy/base.py
+++ b/django/db/backends/dummy/base.py
@@ -12,13 +12,19 @@ from django.core.exceptions import ImproperlyConfigured
 def complain(*args, **kwargs):
     raise ImproperlyConfigured, "You haven't set the DATABASE_ENGINE setting yet."
 
+def ignore(*args, **kwargs):
+    pass
+
 class DatabaseError(Exception):
     pass
 
+class IntegrityError(DatabaseError):
+    pass
+
 class DatabaseWrapper:
     cursor = complain
     _commit = complain
-    _rollback = complain
+    _rollback = ignore
 
     def __init__(self, **kwargs):
         pass
@@ -36,6 +42,10 @@ get_date_extract_sql = complain
 get_date_trunc_sql = complain
 get_limit_offset_sql = complain
 get_random_function_sql = complain
+get_deferrable_sql = complain
 get_fulltext_search_sql = complain
 get_drop_foreignkey_sql = complain
+get_sql_flush = complain
+get_sql_sequence_reset = complain
+
 OPERATOR_MAPPING = {}
diff --git a/django/db/backends/mysql/base.py b/django/db/backends/mysql/base.py
index e7e060e6c2..d4cb1fa964 100644
--- a/django/db/backends/mysql/base.py
+++ b/django/db/backends/mysql/base.py
@@ -10,19 +10,34 @@ try:
 except ImportError, e:
     from django.core.exceptions import ImproperlyConfigured
     raise ImproperlyConfigured, "Error loading MySQLdb module: %s" % e
+
+# We want version (1, 2, 1, 'final', 2) or later. We can't just use
+# lexicographic ordering in this check because then (1, 2, 1, 'gamma')
+# inadvertently passes the version test.
+version = Database.version_info
+if (version < (1,2,1) or (version[:3] == (1, 2, 1) and
+        (len(version) < 5 or version[3] != 'final' or version[4] < 2))):
+    raise ImportError, "MySQLdb-1.2.1p2 or newer is required; you have %s" % Database.__version__
+
 from MySQLdb.converters import conversions
 from MySQLdb.constants import FIELD_TYPE
 import types
 import re
 
 DatabaseError = Database.DatabaseError
+IntegrityError = Database.IntegrityError
 
+# MySQLdb-1.2.1 supports the Python boolean type, and only uses datetime
+# module for time-related columns; older versions could have used mx.DateTime
+# or strings if there were no datetime module. However, MySQLdb still returns
+# TIME columns as timedelta -- they are more like timedelta in terms of actual
+# behavior as they are signed and include days -- and Django expects time, so
+# we still need to override that.
 django_conversions = conversions.copy()
 django_conversions.update({
-    types.BooleanType: util.rev_typecast_boolean,
-    FIELD_TYPE.DATETIME: util.typecast_timestamp,
-    FIELD_TYPE.DATE: util.typecast_date,
     FIELD_TYPE.TIME: util.typecast_time,
+    FIELD_TYPE.DECIMAL: util.typecast_decimal,
+    FIELD_TYPE.NEWDECIMAL: util.typecast_decimal,
 })
 
 # This should match the numerical portion of the version numbers (we can treat
@@ -31,31 +46,12 @@ django_conversions.update({
 # http://dev.mysql.com/doc/refman/5.0/en/news.html .
 server_version_re = re.compile(r'(\d{1,2})\.(\d{1,2})\.(\d{1,2})')
 
-# This is an extra debug layer over MySQL queries, to display warnings.
-# It's only used when DEBUG=True.
-class MysqlDebugWrapper:
-    def __init__(self, cursor):
-        self.cursor = cursor
-
-    def execute(self, sql, params=()):
-        try:
-            return self.cursor.execute(sql, params)
-        except Database.Warning, w:
-            self.cursor.execute("SHOW WARNINGS")
-            raise Database.Warning, "%s: %s" % (w, self.cursor.fetchall())
-
-    def executemany(self, sql, param_list):
-        try:
-            return self.cursor.executemany(sql, param_list)
-        except Database.Warning, w:
-            self.cursor.execute("SHOW WARNINGS")
-            raise Database.Warning, "%s: %s" % (w, self.cursor.fetchall())
-
-    def __getattr__(self, attr):
-        if self.__dict__.has_key(attr):
-            return self.__dict__[attr]
-        else:
-            return getattr(self.cursor, attr)
+# MySQLdb-1.2.1 and newer automatically makes use of SHOW WARNINGS on
+# MySQL-4.1 and newer, so the MysqlDebugWrapper is unnecessary. Since the
+# point is to raise Warnings as exceptions, this can be done with the Python
+# warning module, and this is setup when the connection is created, and the
+# standard util.CursorDebugWrapper can be used. Also, using sql_mode
+# TRADITIONAL will automatically cause most warnings to be treated as errors.
 
 try:
     # Only exists in Python 2.4+
@@ -83,33 +79,41 @@ class DatabaseWrapper(local):
 
     def cursor(self):
         from django.conf import settings
+        from warnings import filterwarnings
         if not self._valid_connection():
             kwargs = {
-                'user': settings.DATABASE_USER,
-                'db': settings.DATABASE_NAME,
-                'passwd': settings.DATABASE_PASSWORD,
                 'conv': django_conversions,
+                'charset': 'utf8',
+                'use_unicode': False,
             }
+            if settings.DATABASE_USER:
+                kwargs['user'] = settings.DATABASE_USER
+            if settings.DATABASE_NAME:
+                kwargs['db'] = settings.DATABASE_NAME
+            if settings.DATABASE_PASSWORD:
+                kwargs['passwd'] = settings.DATABASE_PASSWORD
             if settings.DATABASE_HOST.startswith('/'):
                 kwargs['unix_socket'] = settings.DATABASE_HOST
-            else:
+            elif settings.DATABASE_HOST:
                 kwargs['host'] = settings.DATABASE_HOST
             if settings.DATABASE_PORT:
                 kwargs['port'] = int(settings.DATABASE_PORT)
             kwargs.update(self.options)
             self.connection = Database.connect(**kwargs)
-        cursor = self.connection.cursor()
-        if self.connection.get_server_info() >= '4.1':
-            cursor.execute("SET NAMES 'utf8'")
+            cursor = self.connection.cursor()
+        else:
+            cursor = self.connection.cursor()
         if settings.DEBUG:
-            return util.CursorDebugWrapper(MysqlDebugWrapper(cursor), self)
+            filterwarnings("error", category=Database.Warning)
+            return util.CursorDebugWrapper(cursor, self)
         return cursor
 
     def _commit(self):
-        self.connection.commit()
+        if self.connection is not None:
+            self.connection.commit()
 
     def _rollback(self):
-        if self.connection:
+        if self.connection is not None:
             try:
                 self.connection.rollback()
             except Database.NotSupportedError:
@@ -172,6 +176,9 @@ def get_limit_offset_sql(limit, offset=None):
 def get_random_function_sql():
     return "RAND()"
 
+def get_deferrable_sql():
+    return ""
+
 def get_fulltext_search_sql(field_name):
     return 'MATCH (%s) AGAINST (%%s IN BOOLEAN MODE)' % field_name
 
@@ -181,6 +188,41 @@ def get_drop_foreignkey_sql():
 def get_pk_default_value():
     return "DEFAULT"
 
+def get_sql_flush(style, tables, sequences):
+    """Return a list of SQL statements required to remove all data from
+    all tables in the database (without actually removing the tables
+    themselves) and put the database in an empty 'initial' state
+    
+    """
+    # NB: The generated SQL below is specific to MySQL
+    # 'TRUNCATE x;', 'TRUNCATE y;', 'TRUNCATE z;'... style SQL statements
+    # to clear all tables of all data
+    if tables:
+        sql = ['SET FOREIGN_KEY_CHECKS = 0;'] + \
+              ['%s %s;' % \
+                (style.SQL_KEYWORD('TRUNCATE'),
+                 style.SQL_FIELD(quote_name(table))
+                )  for table in tables] + \
+              ['SET FOREIGN_KEY_CHECKS = 1;']
+              
+        # 'ALTER TABLE table AUTO_INCREMENT = 1;'... style SQL statements
+        # to reset sequence indices
+        sql.extend(["%s %s %s %s %s;" % \
+            (style.SQL_KEYWORD('ALTER'),
+             style.SQL_KEYWORD('TABLE'),
+             style.SQL_TABLE(quote_name(sequence['table'])),
+             style.SQL_KEYWORD('AUTO_INCREMENT'),
+             style.SQL_FIELD('= 1'),
+            ) for sequence in sequences])
+        return sql
+    else:
+        return []
+
+def get_sql_sequence_reset(style, model_list):
+    "Returns a list of the SQL statements to reset sequences for the given models."
+    # No sequence reset required
+    return []
+
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'LIKE %s',
diff --git a/django/db/backends/mysql/client.py b/django/db/backends/mysql/client.py
index f9d6297b8e..116074a9ce 100644
--- a/django/db/backends/mysql/client.py
+++ b/django/db/backends/mysql/client.py
@@ -3,12 +3,25 @@ import os
 
 def runshell():
     args = ['']
-    args += ["--user=%s" % settings.DATABASE_USER]
-    if settings.DATABASE_PASSWORD:
-        args += ["--password=%s" % settings.DATABASE_PASSWORD]
-    if settings.DATABASE_HOST:
-        args += ["--host=%s" % settings.DATABASE_HOST]
-    if settings.DATABASE_PORT:
-        args += ["--port=%s" % settings.DATABASE_PORT]
-    args += [settings.DATABASE_NAME]
+    db = settings.DATABASE_OPTIONS.get('db', settings.DATABASE_NAME)
+    user = settings.DATABASE_OPTIONS.get('user', settings.DATABASE_USER)
+    passwd = settings.DATABASE_OPTIONS.get('passwd', settings.DATABASE_PASSWORD)
+    host = settings.DATABASE_OPTIONS.get('host', settings.DATABASE_HOST)
+    port = settings.DATABASE_OPTIONS.get('port', settings.DATABASE_PORT)
+    defaults_file = settings.DATABASE_OPTIONS.get('read_default_file')
+    # Seems to be no good way to set sql_mode with CLI
+    
+    if defaults_file:
+        args += ["--defaults-file=%s" % defaults_file]
+    if user:
+        args += ["--user=%s" % user]
+    if passwd:
+        args += ["--password=%s" % passwd]
+    if host:
+        args += ["--host=%s" % host]
+    if port:
+        args += ["--port=%s" % port]
+    if db:
+        args += [db]
+
     os.execvp('mysql', args)
diff --git a/django/db/backends/mysql/creation.py b/django/db/backends/mysql/creation.py
index 116b490124..1b23fbff6e 100644
--- a/django/db/backends/mysql/creation.py
+++ b/django/db/backends/mysql/creation.py
@@ -9,9 +9,10 @@ DATA_TYPES = {
     'CommaSeparatedIntegerField': 'varchar(%(maxlength)s)',
     'DateField':         'date',
     'DateTimeField':     'datetime',
+    'DecimalField':      'numeric(%(max_digits)s, %(decimal_places)s)',
     'FileField':         'varchar(100)',
     'FilePathField':     'varchar(100)',
-    'FloatField':        'numeric(%(max_digits)s, %(decimal_places)s)',
+    'FloatField':        'double precision',
     'ImageField':        'varchar(100)',
     'IntegerField':      'integer',
     'IPAddressField':    'char(15)',
@@ -25,6 +26,5 @@ DATA_TYPES = {
     'SmallIntegerField': 'smallint',
     'TextField':         'longtext',
     'TimeField':         'time',
-    'URLField':          'varchar(200)',
     'USStateField':      'varchar(2)',
 }
diff --git a/django/db/backends/mysql/introspection.py b/django/db/backends/mysql/introspection.py
index 7829457fa9..39733311c5 100644
--- a/django/db/backends/mysql/introspection.py
+++ b/django/db/backends/mysql/introspection.py
@@ -76,7 +76,7 @@ def get_indexes(cursor, table_name):
 DATA_TYPES_REVERSE = {
     FIELD_TYPE.BLOB: 'TextField',
     FIELD_TYPE.CHAR: 'CharField',
-    FIELD_TYPE.DECIMAL: 'FloatField',
+    FIELD_TYPE.DECIMAL: 'DecimalField',
     FIELD_TYPE.DATE: 'DateField',
     FIELD_TYPE.DATETIME: 'DateTimeField',
     FIELD_TYPE.DOUBLE: 'FloatField',
@@ -85,7 +85,7 @@ DATA_TYPES_REVERSE = {
     FIELD_TYPE.LONG: 'IntegerField',
     FIELD_TYPE.LONGLONG: 'IntegerField',
     FIELD_TYPE.SHORT: 'IntegerField',
-    FIELD_TYPE.STRING: 'TextField',
+    FIELD_TYPE.STRING: 'CharField',
     FIELD_TYPE.TIMESTAMP: 'DateTimeField',
     FIELD_TYPE.TINY: 'IntegerField',
     FIELD_TYPE.TINY_BLOB: 'TextField',
diff --git a/django/db/backends/mysql_old/__init__.py b/django/db/backends/mysql_old/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/django/db/backends/mysql_old/__init__.py
diff --git a/django/db/backends/mysql_old/base.py b/django/db/backends/mysql_old/base.py
new file mode 100644
index 0000000000..ac3b75efde
--- /dev/null
+++ b/django/db/backends/mysql_old/base.py
@@ -0,0 +1,240 @@
+"""
+MySQL database backend for Django.
+
+Requires MySQLdb: http://sourceforge.net/projects/mysql-python
+"""
+
+from django.db.backends import util
+try:
+    import MySQLdb as Database
+except ImportError, e:
+    from django.core.exceptions import ImproperlyConfigured
+    raise ImproperlyConfigured, "Error loading MySQLdb module: %s" % e
+from MySQLdb.converters import conversions
+from MySQLdb.constants import FIELD_TYPE
+import types
+import re
+
+DatabaseError = Database.DatabaseError
+IntegrityError = Database.IntegrityError
+
+django_conversions = conversions.copy()
+django_conversions.update({
+    types.BooleanType: util.rev_typecast_boolean,
+    FIELD_TYPE.DATETIME: util.typecast_timestamp,
+    FIELD_TYPE.DATE: util.typecast_date,
+    FIELD_TYPE.TIME: util.typecast_time,
+    FIELD_TYPE.DECIMAL: util.typecast_decimal,
+})
+
+# This should match the numerical portion of the version numbers (we can treat
+# versions like 5.0.24 and 5.0.24a as the same). Based on the list of version
+# at http://dev.mysql.com/doc/refman/4.1/en/news.html and
+# http://dev.mysql.com/doc/refman/5.0/en/news.html .
+server_version_re = re.compile(r'(\d{1,2})\.(\d{1,2})\.(\d{1,2})')
+
+# This is an extra debug layer over MySQL queries, to display warnings.
+# It's only used when DEBUG=True.
+class MysqlDebugWrapper:
+    def __init__(self, cursor):
+        self.cursor = cursor
+
+    def execute(self, sql, params=()):
+        try:
+            return self.cursor.execute(sql, params)
+        except Database.Warning, w:
+            self.cursor.execute("SHOW WARNINGS")
+            raise Database.Warning, "%s: %s" % (w, self.cursor.fetchall())
+
+    def executemany(self, sql, param_list):
+        try:
+            return self.cursor.executemany(sql, param_list)
+        except Database.Warning, w:
+            self.cursor.execute("SHOW WARNINGS")
+            raise Database.Warning, "%s: %s" % (w, self.cursor.fetchall())
+
+    def __getattr__(self, attr):
+        if attr in self.__dict__:
+            return self.__dict__[attr]
+        else:
+            return getattr(self.cursor, attr)
+
+try:
+    # Only exists in Python 2.4+
+    from threading import local
+except ImportError:
+    # Import copy of _thread_local.py from Python 2.4
+    from django.utils._threading_local import local
+
+class DatabaseWrapper(local):
+    def __init__(self, **kwargs):
+        self.connection = None
+        self.queries = []
+        self.server_version = None
+        self.options = kwargs
+
+    def _valid_connection(self):
+        if self.connection is not None:
+            try:
+                self.connection.ping()
+                return True
+            except DatabaseError:
+                self.connection.close()
+                self.connection = None
+        return False
+
+    def cursor(self):
+        from django.conf import settings
+        if not self._valid_connection():
+            kwargs = {
+                'user': settings.DATABASE_USER,
+                'db': settings.DATABASE_NAME,
+                'passwd': settings.DATABASE_PASSWORD,
+                'conv': django_conversions,
+            }
+            if settings.DATABASE_HOST.startswith('/'):
+                kwargs['unix_socket'] = settings.DATABASE_HOST
+            else:
+                kwargs['host'] = settings.DATABASE_HOST
+            if settings.DATABASE_PORT:
+                kwargs['port'] = int(settings.DATABASE_PORT)
+            kwargs.update(self.options)
+            self.connection = Database.connect(**kwargs)
+            cursor = self.connection.cursor()
+            if self.connection.get_server_info() >= '4.1':
+                cursor.execute("SET NAMES 'utf8'")
+        else:
+            cursor = self.connection.cursor()
+        if settings.DEBUG:
+            return util.CursorDebugWrapper(MysqlDebugWrapper(cursor), self)
+        return cursor
+
+    def _commit(self):
+        if self.connection is not None:
+            self.connection.commit()
+
+    def _rollback(self):
+        if self.connection is not None:
+            try:
+                self.connection.rollback()
+            except Database.NotSupportedError:
+                pass
+
+    def close(self):
+        if self.connection is not None:
+            self.connection.close()
+            self.connection = None
+
+    def get_server_version(self):
+        if not self.server_version:
+            if not self._valid_connection():
+                self.cursor()
+            m = server_version_re.match(self.connection.get_server_info())
+            if not m:
+                raise Exception('Unable to determine MySQL version from version string %r' % self.connection.get_server_info())
+            self.server_version = tuple([int(x) for x in m.groups()])
+        return self.server_version
+
+supports_constraints = True
+
+def quote_name(name):
+    if name.startswith("`") and name.endswith("`"):
+        return name # Quoting once is enough.
+    return "`%s`" % name
+
+dictfetchone = util.dictfetchone
+dictfetchmany = util.dictfetchmany
+dictfetchall  = util.dictfetchall
+
+def get_last_insert_id(cursor, table_name, pk_name):
+    return cursor.lastrowid
+
+def get_date_extract_sql(lookup_type, table_name):
+    # lookup_type is 'year', 'month', 'day'
+    # http://dev.mysql.com/doc/mysql/en/date-and-time-functions.html
+    return "EXTRACT(%s FROM %s)" % (lookup_type.upper(), table_name)
+
+def get_date_trunc_sql(lookup_type, field_name):
+    # lookup_type is 'year', 'month', 'day'
+    fields = ['year', 'month', 'day', 'hour', 'minute', 'second']
+    format = ('%%Y-', '%%m', '-%%d', ' %%H:', '%%i', ':%%s') # Use double percents to escape.
+    format_def = ('0000-', '01', '-01', ' 00:', '00', ':00')
+    try:
+        i = fields.index(lookup_type) + 1
+    except ValueError:
+        sql = field_name
+    else:
+        format_str = ''.join([f for f in format[:i]] + [f for f in format_def[i:]])
+        sql = "CAST(DATE_FORMAT(%s, '%s') AS DATETIME)" % (field_name, format_str)
+    return sql
+
+def get_limit_offset_sql(limit, offset=None):
+    sql = "LIMIT "
+    if offset and offset != 0:
+        sql += "%s," % offset
+    return sql + str(limit)
+
+def get_random_function_sql():
+    return "RAND()"
+
+def get_deferrable_sql():
+    return ""
+
+def get_fulltext_search_sql(field_name):
+    return 'MATCH (%s) AGAINST (%%s IN BOOLEAN MODE)' % field_name
+
+def get_drop_foreignkey_sql():
+    return "DROP FOREIGN KEY"
+
+def get_pk_default_value():
+    return "DEFAULT"
+
+def get_sql_flush(style, tables, sequences):
+    """Return a list of SQL statements required to remove all data from
+    all tables in the database (without actually removing the tables
+    themselves) and put the database in an empty 'initial' state
+    
+    """
+    # NB: The generated SQL below is specific to MySQL
+    # 'TRUNCATE x;', 'TRUNCATE y;', 'TRUNCATE z;'... style SQL statements
+    # to clear all tables of all data
+    if tables:
+        sql = ['SET FOREIGN_KEY_CHECKS = 0;'] + \
+              ['%s %s;' % \
+                (style.SQL_KEYWORD('TRUNCATE'),
+                 style.SQL_FIELD(quote_name(table))
+                )  for table in tables] + \
+              ['SET FOREIGN_KEY_CHECKS = 1;']
+              
+        # 'ALTER TABLE table AUTO_INCREMENT = 1;'... style SQL statements
+        # to reset sequence indices
+        sql.extend(["%s %s %s %s %s;" % \
+            (style.SQL_KEYWORD('ALTER'),
+             style.SQL_KEYWORD('TABLE'),
+             style.SQL_TABLE(quote_name(sequence['table'])),
+             style.SQL_KEYWORD('AUTO_INCREMENT'),
+             style.SQL_FIELD('= 1'),
+            ) for sequence in sequences])
+        return sql
+    else:
+        return []
+
+def get_sql_sequence_reset(style, model_list):
+    "Returns a list of the SQL statements to reset sequences for the given models."
+    # No sequence reset required
+    return []
+
+OPERATOR_MAPPING = {
+    'exact': '= %s',
+    'iexact': 'LIKE %s',
+    'contains': 'LIKE BINARY %s',
+    'icontains': 'LIKE %s',
+    'gt': '> %s',
+    'gte': '>= %s',
+    'lt': '< %s',
+    'lte': '<= %s',
+    'startswith': 'LIKE BINARY %s',
+    'endswith': 'LIKE BINARY %s',
+    'istartswith': 'LIKE %s',
+    'iendswith': 'LIKE %s',
+}
diff --git a/django/db/backends/mysql_old/client.py b/django/db/backends/mysql_old/client.py
new file mode 100644
index 0000000000..f9d6297b8e
--- /dev/null
+++ b/django/db/backends/mysql_old/client.py
@@ -0,0 +1,14 @@
+from django.conf import settings
+import os
+
+def runshell():
+    args = ['']
+    args += ["--user=%s" % settings.DATABASE_USER]
+    if settings.DATABASE_PASSWORD:
+        args += ["--password=%s" % settings.DATABASE_PASSWORD]
+    if settings.DATABASE_HOST:
+        args += ["--host=%s" % settings.DATABASE_HOST]
+    if settings.DATABASE_PORT:
+        args += ["--port=%s" % settings.DATABASE_PORT]
+    args += [settings.DATABASE_NAME]
+    os.execvp('mysql', args)
diff --git a/django/db/backends/mysql_old/creation.py b/django/db/backends/mysql_old/creation.py
new file mode 100644
index 0000000000..1b23fbff6e
--- /dev/null
+++ b/django/db/backends/mysql_old/creation.py
@@ -0,0 +1,30 @@
+# This dictionary maps Field objects to their associated MySQL column
+# types, as strings. Column-type strings can contain format strings; they'll
+# be interpolated against the values of Field.__dict__ before being output.
+# If a column type is set to None, it won't be included in the output.
+DATA_TYPES = {
+    'AutoField':         'integer AUTO_INCREMENT',
+    'BooleanField':      'bool',
+    'CharField':         'varchar(%(maxlength)s)',
+    'CommaSeparatedIntegerField': 'varchar(%(maxlength)s)',
+    'DateField':         'date',
+    'DateTimeField':     'datetime',
+    'DecimalField':      'numeric(%(max_digits)s, %(decimal_places)s)',
+    'FileField':         'varchar(100)',
+    'FilePathField':     'varchar(100)',
+    'FloatField':        'double precision',
+    'ImageField':        'varchar(100)',
+    'IntegerField':      'integer',
+    'IPAddressField':    'char(15)',
+    'ManyToManyField':   None,
+    'NullBooleanField':  'bool',
+    'OneToOneField':     'integer',
+    'PhoneNumberField':  'varchar(20)',
+    'PositiveIntegerField': 'integer UNSIGNED',
+    'PositiveSmallIntegerField': 'smallint UNSIGNED',
+    'SlugField':         'varchar(%(maxlength)s)',
+    'SmallIntegerField': 'smallint',
+    'TextField':         'longtext',
+    'TimeField':         'time',
+    'USStateField':      'varchar(2)',
+}
diff --git a/django/db/backends/mysql_old/introspection.py b/django/db/backends/mysql_old/introspection.py
new file mode 100644
index 0000000000..cb5b8320d9
--- /dev/null
+++ b/django/db/backends/mysql_old/introspection.py
@@ -0,0 +1,95 @@
+from django.db.backends.mysql_old.base import quote_name
+from MySQLdb import ProgrammingError, OperationalError
+from MySQLdb.constants import FIELD_TYPE
+import re
+
+foreign_key_re = re.compile(r"\sCONSTRAINT `[^`]*` FOREIGN KEY \(`([^`]*)`\) REFERENCES `([^`]*)` \(`([^`]*)`\)")
+
+def get_table_list(cursor):
+    "Returns a list of table names in the current database."
+    cursor.execute("SHOW TABLES")
+    return [row[0] for row in cursor.fetchall()]
+
+def get_table_description(cursor, table_name):
+    "Returns a description of the table, with the DB-API cursor.description interface."
+    cursor.execute("SELECT * FROM %s LIMIT 1" % quote_name(table_name))
+    return cursor.description
+
+def _name_to_index(cursor, table_name):
+    """
+    Returns a dictionary of {field_name: field_index} for the given table.
+    Indexes are 0-based.
+    """
+    return dict([(d[0], i) for i, d in enumerate(get_table_description(cursor, table_name))])
+
+def get_relations(cursor, table_name):
+    """
+    Returns a dictionary of {field_index: (field_index_other_table, other_table)}
+    representing all relationships to the given table. Indexes are 0-based.
+    """
+    my_field_dict = _name_to_index(cursor, table_name)
+    constraints = []
+    relations = {}
+    try:
+        # This should work for MySQL 5.0.
+        cursor.execute("""
+            SELECT column_name, referenced_table_name, referenced_column_name
+            FROM information_schema.key_column_usage
+            WHERE table_name = %s
+                AND table_schema = DATABASE()
+                AND referenced_table_name IS NOT NULL
+                AND referenced_column_name IS NOT NULL""", [table_name])
+        constraints.extend(cursor.fetchall())
+    except (ProgrammingError, OperationalError):
+        # Fall back to "SHOW CREATE TABLE", for previous MySQL versions.
+        # Go through all constraints and save the equal matches.
+        cursor.execute("SHOW CREATE TABLE %s" % quote_name(table_name))
+        for row in cursor.fetchall():
+            pos = 0
+            while True:
+                match = foreign_key_re.search(row[1], pos)
+                if match == None:
+                    break
+                pos = match.end()
+                constraints.append(match.groups())
+
+    for my_fieldname, other_table, other_field in constraints:
+        other_field_index = _name_to_index(cursor, other_table)[other_field]
+        my_field_index = my_field_dict[my_fieldname]
+        relations[my_field_index] = (other_field_index, other_table)
+
+    return relations
+
+def get_indexes(cursor, table_name):
+    """
+    Returns a dictionary of fieldname -> infodict for the given table,
+    where each infodict is in the format:
+        {'primary_key': boolean representing whether it's the primary key,
+         'unique': boolean representing whether it's a unique index}
+    """
+    cursor.execute("SHOW INDEX FROM %s" % quote_name(table_name))
+    indexes = {}
+    for row in cursor.fetchall():
+        indexes[row[4]] = {'primary_key': (row[2] == 'PRIMARY'), 'unique': not bool(row[1])}
+    return indexes
+
+DATA_TYPES_REVERSE = {
+    FIELD_TYPE.BLOB: 'TextField',
+    FIELD_TYPE.CHAR: 'CharField',
+    FIELD_TYPE.DECIMAL: 'DecimalField',
+    FIELD_TYPE.DATE: 'DateField',
+    FIELD_TYPE.DATETIME: 'DateTimeField',
+    FIELD_TYPE.DOUBLE: 'FloatField',
+    FIELD_TYPE.FLOAT: 'FloatField',
+    FIELD_TYPE.INT24: 'IntegerField',
+    FIELD_TYPE.LONG: 'IntegerField',
+    FIELD_TYPE.LONGLONG: 'IntegerField',
+    FIELD_TYPE.SHORT: 'IntegerField',
+    FIELD_TYPE.STRING: 'TextField',
+    FIELD_TYPE.TIMESTAMP: 'DateTimeField',
+    FIELD_TYPE.TINY: 'IntegerField',
+    FIELD_TYPE.TINY_BLOB: 'TextField',
+    FIELD_TYPE.MEDIUM_BLOB: 'TextField',
+    FIELD_TYPE.LONG_BLOB: 'TextField',
+    FIELD_TYPE.VAR_STRING: 'CharField',
+}
diff --git a/django/db/backends/oracle/base.py b/django/db/backends/oracle/base.py
index 3a13f39546..2bc88bb7b9 100644
--- a/django/db/backends/oracle/base.py
+++ b/django/db/backends/oracle/base.py
@@ -12,6 +12,7 @@ except ImportError, e:
     raise ImproperlyConfigured, "Error loading cx_Oracle module: %s" % e
 
 DatabaseError = Database.Error
+IntegrityError = Database.IntegrityError
 
 try:
     # Only exists in Python 2.4+
@@ -43,10 +44,11 @@ class DatabaseWrapper(local):
         return FormatStylePlaceholderCursor(self.connection)
 
     def _commit(self):
-        self.connection.commit()
+        if self.connection is not None:
+            self.connection.commit()
 
     def _rollback(self):
-        if self.connection:
+        if self.connection is not None:
             try:
                 self.connection.rollback()
             except Database.NotSupportedError:
@@ -108,6 +110,9 @@ def get_limit_offset_sql(limit, offset=None):
 def get_random_function_sql():
     return "DBMS_RANDOM.RANDOM"
 
+def get_deferrable_sql():
+    return " DEFERRABLE INITIALLY DEFERRED"
+
 def get_fulltext_search_sql(field_name):
     raise NotImplementedError
 
@@ -117,6 +122,24 @@ def get_drop_foreignkey_sql():
 def get_pk_default_value():
     return "DEFAULT"
 
+def get_sql_flush(style, tables, sequences):
+    """Return a list of SQL statements required to remove all data from
+    all tables in the database (without actually removing the tables
+    themselves) and put the database in an empty 'initial' state
+    """
+    # Return a list of 'TRUNCATE x;', 'TRUNCATE y;', 'TRUNCATE z;'... style SQL statements
+    # TODO - SQL not actually tested against Oracle yet!
+    # TODO - autoincrement indices reset required? See other get_sql_flush() implementations
+    sql = ['%s %s;' % \
+            (style.SQL_KEYWORD('TRUNCATE'),
+             style.SQL_FIELD(quote_name(table))
+             )  for table in tables]
+
+def get_sql_sequence_reset(style, model_list):
+    "Returns a list of the SQL statements to reset sequences for the given models."
+    # No sequence reset required
+    return []
+
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'LIKE %s',
diff --git a/django/db/backends/oracle/creation.py b/django/db/backends/oracle/creation.py
index d45ceb64f5..14a864ac28 100644
--- a/django/db/backends/oracle/creation.py
+++ b/django/db/backends/oracle/creation.py
@@ -5,9 +5,10 @@ DATA_TYPES = {
     'CommaSeparatedIntegerField': 'varchar2(%(maxlength)s)',
     'DateField':         'date',
     'DateTimeField':     'date',
+    'DecimalField':      'number(%(max_digits)s, %(decimal_places)s)',
     'FileField':         'varchar2(100)',
     'FilePathField':     'varchar2(100)',
-    'FloatField':        'number(%(max_digits)s, %(decimal_places)s)',
+    'FloatField':        'double precision',
     'ImageField':        'varchar2(100)',
     'IntegerField':      'integer',
     'IPAddressField':    'char(15)',
@@ -21,6 +22,5 @@ DATA_TYPES = {
     'SmallIntegerField': 'smallint',
     'TextField':         'long',
     'TimeField':         'timestamp',
-    'URLField':          'varchar(200)',
     'USStateField':      'varchar(2)',
 }
diff --git a/django/db/backends/oracle/introspection.py b/django/db/backends/oracle/introspection.py
index ecc8f372a8..7634206178 100644
--- a/django/db/backends/oracle/introspection.py
+++ b/django/db/backends/oracle/introspection.py
@@ -46,5 +46,5 @@ DATA_TYPES_REVERSE = {
     1114: 'DateTimeField',
     1184: 'DateTimeField',
     1266: 'TimeField',
-    1700: 'FloatField',
+    1700: 'DecimalField',
 }
diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py
index e44bc0b560..fedbb6b7f1 100644
--- a/django/db/backends/postgresql/base.py
+++ b/django/db/backends/postgresql/base.py
@@ -12,6 +12,7 @@ except ImportError, e:
     raise ImproperlyConfigured, "Error loading psycopg module: %s" % e
 
 DatabaseError = Database.DatabaseError
+IntegrityError = Database.IntegrityError
 
 try:
     # Only exists in Python 2.4+
@@ -20,6 +21,40 @@ except ImportError:
     # Import copy of _thread_local.py from Python 2.4
     from django.utils._threading_local import local
 
+def smart_basestring(s, charset):
+    if isinstance(s, unicode):
+        return s.encode(charset)
+    return s
+
+class UnicodeCursorWrapper(object):
+    """
+    A thin wrapper around psycopg cursors that allows them to accept Unicode
+    strings as params.
+
+    This is necessary because psycopg doesn't apply any DB quoting to
+    parameters that are Unicode strings. If a param is Unicode, this will
+    convert it to a bytestring using DEFAULT_CHARSET before passing it to
+    psycopg.
+    """
+    def __init__(self, cursor, charset):
+        self.cursor = cursor
+        self.charset = charset
+
+    def execute(self, sql, params=()):
+        return self.cursor.execute(sql, [smart_basestring(p, self.charset) for p in params])
+
+    def executemany(self, sql, param_list):
+        new_param_list = [tuple([smart_basestring(p, self.charset) for p in params]) for params in param_list]
+        return self.cursor.executemany(sql, new_param_list)
+
+    def __getattr__(self, attr):
+        if attr in self.__dict__:
+            return self.__dict__[attr]
+        else:
+            return getattr(self.cursor, attr)
+
+postgres_version = None
+
 class DatabaseWrapper(local):
     def __init__(self, **kwargs):
         self.connection = None
@@ -28,7 +63,9 @@ class DatabaseWrapper(local):
 
     def cursor(self):
         from django.conf import settings
+        set_tz = False
         if self.connection is None:
+            set_tz = True
             if settings.DATABASE_NAME == '':
                 from django.core.exceptions import ImproperlyConfigured
                 raise ImproperlyConfigured, "You need to specify DATABASE_NAME in your Django settings file."
@@ -44,16 +81,23 @@ class DatabaseWrapper(local):
             self.connection = Database.connect(conn_string, **self.options)
             self.connection.set_isolation_level(1) # make transactions transparent to all cursors
         cursor = self.connection.cursor()
-        cursor.execute("SET TIME ZONE %s", [settings.TIME_ZONE])
+        if set_tz:
+            cursor.execute("SET TIME ZONE %s", [settings.TIME_ZONE])
+        cursor = UnicodeCursorWrapper(cursor, settings.DEFAULT_CHARSET)
+        global postgres_version
+        if not postgres_version:
+            cursor.execute("SELECT version()")
+            postgres_version = [int(val) for val in cursor.fetchone()[0].split()[1].split('.')]        
         if settings.DEBUG:
             return util.CursorDebugWrapper(cursor, self)
         return cursor
 
     def _commit(self):
-        return self.connection.commit()
+        if self.connection is not None:
+            return self.connection.commit()
 
     def _rollback(self):
-        if self.connection:
+        if self.connection is not None:
             return self.connection.rollback()
 
     def close(self):
@@ -103,6 +147,9 @@ def get_limit_offset_sql(limit, offset=None):
 def get_random_function_sql():
     return "RANDOM()"
 
+def get_deferrable_sql():
+    return " DEFERRABLE INITIALLY DEFERRED"
+    
 def get_fulltext_search_sql(field_name):
     raise NotImplementedError
 
@@ -112,6 +159,91 @@ def get_drop_foreignkey_sql():
 def get_pk_default_value():
     return "DEFAULT"
 
+def get_sql_flush(style, tables, sequences):
+    """Return a list of SQL statements required to remove all data from
+    all tables in the database (without actually removing the tables
+    themselves) and put the database in an empty 'initial' state
+    
+    """    
+    if tables:
+        if postgres_version[0] >= 8 and postgres_version[1] >= 1:
+            # Postgres 8.1+ can do 'TRUNCATE x, y, z...;'. In fact, it *has to* in order to be able to
+            # truncate tables referenced by a foreign key in any other table. The result is a
+            # single SQL TRUNCATE statement.
+            sql = ['%s %s;' % \
+                (style.SQL_KEYWORD('TRUNCATE'),
+                 style.SQL_FIELD(', '.join([quote_name(table) for table in tables]))
+            )]
+        else:
+            # Older versions of Postgres can't do TRUNCATE in a single call, so they must use 
+            # a simple delete.
+            sql = ['%s %s %s;' % \
+                    (style.SQL_KEYWORD('DELETE'),
+                     style.SQL_KEYWORD('FROM'),
+                     style.SQL_FIELD(quote_name(table))
+                     ) for table in tables]
+
+        # 'ALTER SEQUENCE sequence_name RESTART WITH 1;'... style SQL statements
+        # to reset sequence indices
+        for sequence_info in sequences:
+            table_name = sequence_info['table']
+            column_name = sequence_info['column']
+            if column_name and len(column_name)>0:
+                # sequence name in this case will be <table>_<column>_seq
+                sql.append("%s %s %s %s %s %s;" % \
+                    (style.SQL_KEYWORD('ALTER'),
+                    style.SQL_KEYWORD('SEQUENCE'),
+                    style.SQL_FIELD(quote_name('%s_%s_seq' % (table_name, column_name))),
+                    style.SQL_KEYWORD('RESTART'),
+                    style.SQL_KEYWORD('WITH'),
+                    style.SQL_FIELD('1')
+                    )
+                )
+            else:
+                # sequence name in this case will be <table>_id_seq
+                sql.append("%s %s %s %s %s %s;" % \
+                    (style.SQL_KEYWORD('ALTER'),
+                     style.SQL_KEYWORD('SEQUENCE'),
+                     style.SQL_FIELD(quote_name('%s_id_seq' % table_name)),
+                     style.SQL_KEYWORD('RESTART'),
+                     style.SQL_KEYWORD('WITH'),
+                     style.SQL_FIELD('1')
+                     )
+                )
+        return sql
+    else:
+        return []
+
+def get_sql_sequence_reset(style, model_list):
+    "Returns a list of the SQL statements to reset sequences for the given models."
+    from django.db import models
+    output = []
+    for model in model_list:
+        # Use `coalesce` to set the sequence for each model to the max pk value if there are records,
+        # or 1 if there are none. Set the `is_called` property (the third argument to `setval`) to true
+        # if there are records (as the max pk value is already in use), otherwise set it to false.
+        for f in model._meta.fields:
+            if isinstance(f, models.AutoField):
+                output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
+                    (style.SQL_KEYWORD('SELECT'),
+                    style.SQL_FIELD(quote_name('%s_%s_seq' % (model._meta.db_table, f.column))),
+                    style.SQL_FIELD(quote_name(f.column)),
+                    style.SQL_FIELD(quote_name(f.column)),
+                    style.SQL_KEYWORD('IS NOT'),
+                    style.SQL_KEYWORD('FROM'),
+                    style.SQL_TABLE(quote_name(model._meta.db_table))))
+                break # Only one AutoField is allowed per model, so don't bother continuing.
+        for f in model._meta.many_to_many:
+            output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
+                (style.SQL_KEYWORD('SELECT'),
+                style.SQL_FIELD(quote_name('%s_id_seq' % f.m2m_db_table())),
+                style.SQL_FIELD(quote_name('id')),
+                style.SQL_FIELD(quote_name('id')),
+                style.SQL_KEYWORD('IS NOT'),
+                style.SQL_KEYWORD('FROM'),
+                style.SQL_TABLE(f.m2m_db_table())))
+    return output
+        
 # Register these custom typecasts, because Django expects dates/times to be
 # in Python's native (standard-library) datetime/time format, whereas psycopg
 # use mx.DateTime by default.
@@ -122,6 +254,7 @@ except AttributeError:
 Database.register_type(Database.new_type((1083,1266), "TIME", util.typecast_time))
 Database.register_type(Database.new_type((1114,1184), "TIMESTAMP", util.typecast_timestamp))
 Database.register_type(Database.new_type((16,), "BOOLEAN", util.typecast_boolean))
+Database.register_type(Database.new_type((1700,), "NUMERIC", util.typecast_decimal))
 
 OPERATOR_MAPPING = {
     'exact': '= %s',
diff --git a/django/db/backends/postgresql/creation.py b/django/db/backends/postgresql/creation.py
index 65a804ec40..4646b68ab8 100644
--- a/django/db/backends/postgresql/creation.py
+++ b/django/db/backends/postgresql/creation.py
@@ -9,9 +9,10 @@ DATA_TYPES = {
     'CommaSeparatedIntegerField': 'varchar(%(maxlength)s)',
     'DateField':         'date',
     'DateTimeField':     'timestamp with time zone',
+    'DecimalField':      'numeric(%(max_digits)s, %(decimal_places)s)',
     'FileField':         'varchar(100)',
     'FilePathField':     'varchar(100)',
-    'FloatField':        'numeric(%(max_digits)s, %(decimal_places)s)',
+    'FloatField':        'double precision',
     'ImageField':        'varchar(100)',
     'IntegerField':      'integer',
     'IPAddressField':    'inet',
@@ -25,6 +26,5 @@ DATA_TYPES = {
     'SmallIntegerField': 'smallint',
     'TextField':         'text',
     'TimeField':         'time',
-    'URLField':          'varchar(200)',
     'USStateField':      'varchar(2)',
 }
diff --git a/django/db/backends/postgresql/introspection.py b/django/db/backends/postgresql/introspection.py
index 6e1d60c4ff..2605490afd 100644
--- a/django/db/backends/postgresql/introspection.py
+++ b/django/db/backends/postgresql/introspection.py
@@ -72,6 +72,7 @@ DATA_TYPES_REVERSE = {
     21: 'SmallIntegerField',
     23: 'IntegerField',
     25: 'TextField',
+    701: 'FloatField',
     869: 'IPAddressField',
     1043: 'CharField',
     1082: 'DateField',
@@ -79,5 +80,5 @@ DATA_TYPES_REVERSE = {
     1114: 'DateTimeField',
     1184: 'DateTimeField',
     1266: 'TimeField',
-    1700: 'FloatField',
+    1700: 'DecimalField',
 }
diff --git a/django/db/backends/postgresql_psycopg2/base.py b/django/db/backends/postgresql_psycopg2/base.py
index 04322332dc..d9ad363ac1 100644
--- a/django/db/backends/postgresql_psycopg2/base.py
+++ b/django/db/backends/postgresql_psycopg2/base.py
@@ -12,6 +12,7 @@ except ImportError, e:
     raise ImproperlyConfigured, "Error loading psycopg2 module: %s" % e
 
 DatabaseError = Database.DatabaseError
+IntegrityError = Database.IntegrityError
 
 try:
     # Only exists in Python 2.4+
@@ -20,6 +21,8 @@ except ImportError:
     # Import copy of _thread_local.py from Python 2.4
     from django.utils._threading_local import local
 
+postgres_version = None
+
 class DatabaseWrapper(local):
     def __init__(self, **kwargs):
         self.connection = None
@@ -28,7 +31,9 @@ class DatabaseWrapper(local):
 
     def cursor(self):
         from django.conf import settings
+        set_tz = False
         if self.connection is None:
+            set_tz = True
             if settings.DATABASE_NAME == '':
                 from django.core.exceptions import ImproperlyConfigured
                 raise ImproperlyConfigured, "You need to specify DATABASE_NAME in your Django settings file."
@@ -45,16 +50,22 @@ class DatabaseWrapper(local):
             self.connection.set_isolation_level(1) # make transactions transparent to all cursors
         cursor = self.connection.cursor()
         cursor.tzinfo_factory = None
-        cursor.execute("SET TIME ZONE %s", [settings.TIME_ZONE])
+        if set_tz:
+            cursor.execute("SET TIME ZONE %s", [settings.TIME_ZONE])
+        global postgres_version
+        if not postgres_version:
+            cursor.execute("SELECT version()")
+            postgres_version = [int(val) for val in cursor.fetchone()[0].split()[1].split('.')]        
         if settings.DEBUG:
             return util.CursorDebugWrapper(cursor, self)
         return cursor
 
     def _commit(self):
-        return self.connection.commit()
+        if self.connection is not None:
+            return self.connection.commit()
 
     def _rollback(self):
-        if self.connection:
+        if self.connection is not None:
             return self.connection.rollback()
 
     def close(self):
@@ -96,6 +107,9 @@ def get_limit_offset_sql(limit, offset=None):
 def get_random_function_sql():
     return "RANDOM()"
 
+def get_deferrable_sql():
+    return " DEFERRABLE INITIALLY DEFERRED"
+
 def get_fulltext_search_sql(field_name):
     raise NotImplementedError
 
@@ -105,6 +119,88 @@ def get_drop_foreignkey_sql():
 def get_pk_default_value():
     return "DEFAULT"
 
+def get_sql_flush(style, tables, sequences):
+    """Return a list of SQL statements required to remove all data from
+    all tables in the database (without actually removing the tables
+    themselves) and put the database in an empty 'initial' state
+    """
+    if tables:
+        if postgres_version[0] >= 8 and postgres_version[1] >= 1:
+            # Postgres 8.1+ can do 'TRUNCATE x, y, z...;'. In fact, it *has to* in order to be able to
+            # truncate tables referenced by a foreign key in any other table. The result is a
+            # single SQL TRUNCATE statement
+            sql = ['%s %s;' % \
+                    (style.SQL_KEYWORD('TRUNCATE'),
+                     style.SQL_FIELD(', '.join([quote_name(table) for table in tables]))
+                    )]
+        else:
+            sql = ['%s %s %s;' % \
+                    (style.SQL_KEYWORD('DELETE'),
+                     style.SQL_KEYWORD('FROM'),
+                     style.SQL_FIELD(quote_name(table))
+                     ) for table in tables]
+                     
+        # 'ALTER SEQUENCE sequence_name RESTART WITH 1;'... style SQL statements
+        # to reset sequence indices
+        for sequence in sequences:
+            table_name = sequence['table']
+            column_name = sequence['column']
+            if column_name and len(column_name) > 0:
+                # sequence name in this case will be <table>_<column>_seq
+                sql.append("%s %s %s %s %s %s;" % \
+                    (style.SQL_KEYWORD('ALTER'),
+                     style.SQL_KEYWORD('SEQUENCE'),
+                     style.SQL_FIELD(quote_name('%s_%s_seq' % (table_name, column_name))),
+                     style.SQL_KEYWORD('RESTART'),
+                     style.SQL_KEYWORD('WITH'),
+                     style.SQL_FIELD('1')
+                     )
+                )
+            else:
+                # sequence name in this case will be <table>_id_seq
+                sql.append("%s %s %s %s %s %s;" % \
+                    (style.SQL_KEYWORD('ALTER'),
+                     style.SQL_KEYWORD('SEQUENCE'),
+                     style.SQL_FIELD(quote_name('%s_id_seq' % table_name)),
+                     style.SQL_KEYWORD('RESTART'),
+                     style.SQL_KEYWORD('WITH'),
+                     style.SQL_FIELD('1')
+                     )
+                )
+        return sql
+    else:
+        return []
+
+def get_sql_sequence_reset(style, model_list):
+    "Returns a list of the SQL statements to reset sequences for the given models."
+    from django.db import models
+    output = []
+    for model in model_list:
+        # Use `coalesce` to set the sequence for each model to the max pk value if there are records,
+        # or 1 if there are none. Set the `is_called` property (the third argument to `setval`) to true
+        # if there are records (as the max pk value is already in use), otherwise set it to false.
+        for f in model._meta.fields:
+            if isinstance(f, models.AutoField):
+                output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
+                    (style.SQL_KEYWORD('SELECT'),
+                    style.SQL_FIELD(quote_name('%s_%s_seq' % (model._meta.db_table, f.column))),
+                    style.SQL_FIELD(quote_name(f.column)),
+                    style.SQL_FIELD(quote_name(f.column)),
+                    style.SQL_KEYWORD('IS NOT'),
+                    style.SQL_KEYWORD('FROM'),
+                    style.SQL_TABLE(quote_name(model._meta.db_table))))
+                break # Only one AutoField is allowed per model, so don't bother continuing.
+        for f in model._meta.many_to_many:
+            output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
+                (style.SQL_KEYWORD('SELECT'),
+                style.SQL_FIELD(quote_name('%s_id_seq' % f.m2m_db_table())),
+                style.SQL_FIELD(quote_name('id')),
+                style.SQL_FIELD(quote_name('id')),
+                style.SQL_KEYWORD('IS NOT'),
+                style.SQL_KEYWORD('FROM'),
+                style.SQL_TABLE(f.m2m_db_table())))
+    return output
+        
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'ILIKE %s',
diff --git a/django/db/backends/postgresql_psycopg2/introspection.py b/django/db/backends/postgresql_psycopg2/introspection.py
index a546da8c45..aa45fe7db7 100644
--- a/django/db/backends/postgresql_psycopg2/introspection.py
+++ b/django/db/backends/postgresql_psycopg2/introspection.py
@@ -72,6 +72,7 @@ DATA_TYPES_REVERSE = {
     21: 'SmallIntegerField',
     23: 'IntegerField',
     25: 'TextField',
+    701: 'FloatField',
     869: 'IPAddressField',
     1043: 'CharField',
     1082: 'DateField',
@@ -79,5 +80,5 @@ DATA_TYPES_REVERSE = {
     1114: 'DateTimeField',
     1184: 'DateTimeField',
     1266: 'TimeField',
-    1700: 'FloatField',
+    1700: 'DecimalField',
 }
diff --git a/django/db/backends/sqlite3/base.py b/django/db/backends/sqlite3/base.py
index 891320160f..5cd67a32f5 100644
--- a/django/db/backends/sqlite3/base.py
+++ b/django/db/backends/sqlite3/base.py
@@ -17,7 +17,13 @@ except ImportError, e:
         module = 'sqlite3'
     raise ImproperlyConfigured, "Error loading %s module: %s" % (module, e)
 
+try:
+    import decimal
+except ImportError:
+    from django.utils import _decimal as decimal # for Python 2.3
+
 DatabaseError = Database.DatabaseError
+IntegrityError = Database.IntegrityError
 
 Database.register_converter("bool", lambda s: str(s) == '1')
 Database.register_converter("time", util.typecast_time)
@@ -25,6 +31,8 @@ Database.register_converter("date", util.typecast_date)
 Database.register_converter("datetime", util.typecast_timestamp)
 Database.register_converter("timestamp", util.typecast_timestamp)
 Database.register_converter("TIMESTAMP", util.typecast_timestamp)
+Database.register_converter("decimal", util.typecast_decimal)
+Database.register_adapter(decimal.Decimal, util.rev_typecast_decimal)
 
 def utf8rowFactory(cursor, row):
     def utf8(s):
@@ -67,10 +75,11 @@ class DatabaseWrapper(local):
             return cursor
 
     def _commit(self):
-        self.connection.commit()
+        if self.connection is not None:
+            self.connection.commit()
 
     def _rollback(self):
-        if self.connection:
+        if self.connection is not None:
             self.connection.rollback()
 
     def close(self):
@@ -139,6 +148,9 @@ def get_limit_offset_sql(limit, offset=None):
 def get_random_function_sql():
     return "RANDOM()"
 
+def get_deferrable_sql():
+    return ""
+
 def get_fulltext_search_sql(field_name):
     raise NotImplementedError
 
@@ -148,6 +160,29 @@ def get_drop_foreignkey_sql():
 def get_pk_default_value():
     return "NULL"
 
+def get_sql_flush(style, tables, sequences):
+    """Return a list of SQL statements required to remove all data from
+    all tables in the database (without actually removing the tables
+    themselves) and put the database in an empty 'initial' state
+    
+    """
+    # NB: The generated SQL below is specific to SQLite
+    # Note: The DELETE FROM... SQL generated below works for SQLite databases
+    # because constraints don't exist
+    sql = ['%s %s %s;' % \
+            (style.SQL_KEYWORD('DELETE'),
+             style.SQL_KEYWORD('FROM'),
+             style.SQL_FIELD(quote_name(table))
+             ) for table in tables]
+    # Note: No requirement for reset of auto-incremented indices (cf. other
+    # get_sql_flush() implementations). Just return SQL at this point
+    return sql
+
+def get_sql_sequence_reset(style, model_list):
+    "Returns a list of the SQL statements to reset sequences for the given models."
+    # No sequence reset required
+    return []
+    
 def _sqlite_date_trunc(lookup_type, dt):
     try:
         dt = util.typecast_timestamp(dt)
diff --git a/django/db/backends/sqlite3/creation.py b/django/db/backends/sqlite3/creation.py
index e845179e64..e63046ab7d 100644
--- a/django/db/backends/sqlite3/creation.py
+++ b/django/db/backends/sqlite3/creation.py
@@ -8,9 +8,10 @@ DATA_TYPES = {
     'CommaSeparatedIntegerField':   'varchar(%(maxlength)s)',
     'DateField':                    'date',
     'DateTimeField':                'datetime',
+    'DecimalField':                 'decimal',
     'FileField':                    'varchar(100)',
     'FilePathField':                'varchar(100)',
-    'FloatField':                   'numeric(%(max_digits)s, %(decimal_places)s)',
+    'FloatField':                   'real',
     'ImageField':                   'varchar(100)',
     'IntegerField':                 'integer',
     'IPAddressField':               'char(15)',
@@ -24,6 +25,5 @@ DATA_TYPES = {
     'SmallIntegerField':            'smallint',
     'TextField':                    'text',
     'TimeField':                    'time',
-    'URLField':                     'varchar(200)',
     'USStateField':                 'varchar(2)',
 }
diff --git a/django/db/backends/util.py b/django/db/backends/util.py
index d8f86fef4f..81c752e664 100644
--- a/django/db/backends/util.py
+++ b/django/db/backends/util.py
@@ -1,6 +1,11 @@
 import datetime
 from time import time
 
+try:
+    import decimal
+except ImportError:
+    from django.utils import _decimal as decimal    # for Python 2.3
+
 class CursorDebugWrapper(object):
     def __init__(self, cursor, db):
         self.cursor = cursor
@@ -33,7 +38,7 @@ class CursorDebugWrapper(object):
             })
 
     def __getattr__(self, attr):
-        if self.__dict__.has_key(attr):
+        if attr in self.__dict__:
             return self.__dict__[attr]
         else:
             return getattr(self.cursor, attr)
@@ -85,6 +90,11 @@ def typecast_boolean(s):
     if not s: return False
     return str(s)[0].lower() == 't'
 
+def typecast_decimal(s):
+    if s is None or s == '':
+        return None
+    return decimal.Decimal(s)
+
 ###############################################
 # Converters from Python to database (string) #
 ###############################################
@@ -92,6 +102,11 @@ def typecast_boolean(s):
 def rev_typecast_boolean(obj, d):
     return obj and '1' or '0'
 
+def rev_typecast_decimal(d):
+    if d is None:
+        return None
+    return str(d)
+
 ##################################################################################
 # Helper functions for dictfetch* for databases that don't natively support them #
 ##################################################################################
diff --git a/django/db/models/__init__.py b/django/db/models/__init__.py
index 0308dd047a..6c3abb6b59 100644
--- a/django/db/models/__init__.py
+++ b/django/db/models/__init__.py
@@ -8,7 +8,6 @@ from django.db.models.manager import Manager
 from django.db.models.base import Model, AdminOptions
 from django.db.models.fields import *
 from django.db.models.fields.related import ForeignKey, OneToOneField, ManyToManyField, ManyToOneRel, ManyToManyRel, OneToOneRel, TABULAR, STACKED
-from django.db.models.fields.generic import GenericRelation, GenericRel, GenericForeignKey
 from django.db.models import signals
 from django.utils.functional import curry
 from django.utils.text import capfirst
@@ -27,27 +26,3 @@ def permalink(func):
         viewname = bits[0]
         return reverse(bits[0], None, *bits[1:3])
     return inner
-
-class LazyDate(object):
-    """
-    Use in limit_choices_to to compare the field to dates calculated at run time
-    instead of when the model is loaded.  For example::
-
-        ... limit_choices_to = {'date__gt' : models.LazyDate(days=-3)} ...
-
-    which will limit the choices to dates greater than three days ago.
-    """
-    def __init__(self, **kwargs):
-        self.delta = datetime.timedelta(**kwargs)
-
-    def __str__(self):
-        return str(self.__get_value__())
-
-    def __repr__(self):
-        return "<LazyDate: %s>" % self.delta
-
-    def __get_value__(self):
-        return (datetime.datetime.now() + self.delta).date()
-
-    def __getattr__(self, attr):
-        return getattr(self.__get_value__(), attr)
diff --git a/django/db/models/base.py b/django/db/models/base.py
index 70569a2561..a8e6303e1c 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -13,6 +13,7 @@ from django.dispatch import dispatcher
 from django.utils.datastructures import SortedDict
 from django.utils.functional import curry
 from django.conf import settings
+from itertools import izip
 import types
 import sys
 import os
@@ -21,8 +22,13 @@ class ModelBase(type):
     "Metaclass for all models"
     def __new__(cls, name, bases, attrs):
         # If this isn't a subclass of Model, don't do anything special.
-        if not bases or bases == (object,):
-            return type.__new__(cls, name, bases, attrs)
+        try:
+            if not filter(lambda b: issubclass(b, Model), bases):
+                return super(ModelBase, cls).__new__(cls, name, bases, attrs)
+        except NameError:
+            # 'Model' isn't defined yet, meaning we're looking at Django's own
+            # Model class, defined below.
+            return super(ModelBase, cls).__new__(cls, name, bases, attrs)
 
         # Create the class.
         new_class = type.__new__(cls, name, bases, {'__module__': attrs.pop('__module__')})
@@ -36,11 +42,11 @@ class ModelBase(type):
                 new_class._meta.parents.append(base)
                 new_class._meta.parents.extend(base._meta.parents)
 
-        model_module = sys.modules[new_class.__module__]
 
         if getattr(new_class._meta, 'app_label', None) is None:
             # Figure out the app_label by looking one level up.
             # For 'django.contrib.sites.models', this would be 'sites'.
+            model_module = sys.modules[new_class.__module__]
             new_class._meta.app_label = model_module.__name__.split('.')[-2]
 
         # Bail out early if we have already created this class.
@@ -63,7 +69,7 @@ class ModelBase(type):
 
         if getattr(new_class._meta, 'row_level_permissions', False):
             from django.contrib.auth.models import RowLevelPermission
-            gen_rel = django.db.models.GenericRelation(RowLevelPermission, object_id_field="model_id", content_type_field="model_ct")
+            gen_rel = django.contrib.contenttypes.generic.GenericRelation(RowLevelPermission, object_id_field="model_id", content_type_field="model_ct")
             new_class.add_to_class("row_level_permissions", gen_rel)
 
         new_class._prepare()
@@ -95,41 +101,74 @@ class Model(object):
 
     def __init__(self, *args, **kwargs):
         dispatcher.send(signal=signals.pre_init, sender=self.__class__, args=args, kwargs=kwargs)
-        for f in self._meta.fields:
-            if isinstance(f.rel, ManyToOneRel):
-                try:
-                    # Assume object instance was passed in.
-                    rel_obj = kwargs.pop(f.name)
-                except KeyError:
+        
+        # There is a rather weird disparity here; if kwargs, it's set, then args
+        # overrides it. It should be one or the other; don't duplicate the work 
+        # The reason for the kwargs check is that standard iterator passes in by
+        # args, and nstantiation for iteration is 33% faster.
+        args_len = len(args)
+        if args_len > len(self._meta.fields):
+            # Daft, but matches old exception sans the err msg.
+            raise IndexError("Number of args exceeds number of fields")
+
+        fields_iter = iter(self._meta.fields)
+        if not kwargs:
+            # The ordering of the izip calls matter - izip throws StopIteration
+            # when an iter throws it. So if the first iter throws it, the second
+            # is *not* consumed. We rely on this, so don't change the order
+            # without changing the logic.
+            for val, field in izip(args, fields_iter):
+                setattr(self, field.attname, val)
+        else:
+            # Slower, kwargs-ready version.
+            for val, field in izip(args, fields_iter):
+                setattr(self, field.attname, val)
+                kwargs.pop(field.name, None)
+                # Maintain compatibility with existing calls.
+                if isinstance(field.rel, ManyToOneRel):
+                    kwargs.pop(field.attname, None)
+        
+        # Now we're left with the unprocessed fields that *must* come from
+        # keywords, or default.
+        
+        for field in fields_iter:
+            if kwargs:
+                if isinstance(field.rel, ManyToOneRel):
                     try:
-                        # Object instance wasn't passed in -- must be an ID.
-                        val = kwargs.pop(f.attname)
+                        # Assume object instance was passed in.
+                        rel_obj = kwargs.pop(field.name)
                     except KeyError:
-                        val = f.get_default()
-                else:
-                    # Object instance was passed in.
-                    # Special case: You can pass in "None" for related objects if it's allowed.
-                    if rel_obj is None and f.null:
-                        val = None
-                    else:
                         try:
-                            val = getattr(rel_obj, f.rel.get_related_field().attname)
-                        except AttributeError:
-                            raise TypeError, "Invalid value: %r should be a %s instance, not a %s" % (f.name, f.rel.to, type(rel_obj))
-                setattr(self, f.attname, val)
+                            # Object instance wasn't passed in -- must be an ID.
+                            val = kwargs.pop(field.attname)
+                        except KeyError:
+                            val = field.get_default()
+                    else:
+                        # Object instance was passed in. Special case: You can
+                        # pass in "None" for related objects if it's allowed.
+                        if rel_obj is None and field.null:
+                            val = None
+                        else:
+                            try:
+                                val = getattr(rel_obj, field.rel.get_related_field().attname)
+                            except AttributeError:
+                                raise TypeError("Invalid value: %r should be a %s instance, not a %s" % 
+                                    (field.name, field.rel.to, type(rel_obj)))
+                else:
+                    val = kwargs.pop(field.attname, field.get_default())
             else:
-                val = kwargs.pop(f.attname, f.get_default())
-                setattr(self, f.attname, val)
-        for prop in kwargs.keys():
-            try:
-                if isinstance(getattr(self.__class__, prop), property):
-                    setattr(self, prop, kwargs.pop(prop))
-            except AttributeError:
-                pass
+                val = field.get_default()
+            setattr(self, field.attname, val)
+
         if kwargs:
-            raise TypeError, "'%s' is an invalid keyword argument for this function" % kwargs.keys()[0]
-        for i, arg in enumerate(args):
-            setattr(self, self._meta.fields[i].attname, arg)
+            for prop in kwargs.keys():
+                try:
+                    if isinstance(getattr(self.__class__, prop), property):
+                        setattr(self, prop, kwargs.pop(prop))
+                except AttributeError:
+                    pass
+            if kwargs:
+                raise TypeError, "'%s' is an invalid keyword argument for this function" % kwargs.keys()[0]
         dispatcher.send(signal=signals.post_init, sender=self.__class__, instance=self)
 
     def add_to_class(cls, name, value):
@@ -327,7 +366,7 @@ class Model(object):
     def _get_FIELD_size(self, field):
         return os.path.getsize(self._get_FIELD_filename(field))
 
-    def _save_FIELD_file(self, field, filename, raw_contents):
+    def _save_FIELD_file(self, field, filename, raw_contents, save=True):
         directory = field.get_directory_name()
         try: # Create the date-based directory if it doesn't exist.
             os.makedirs(os.path.join(settings.MEDIA_ROOT, directory))
@@ -362,8 +401,9 @@ class Model(object):
             if field.height_field:
                 setattr(self, field.height_field, height)
 
-        # Save the object, because it has changed.
-        self.save()
+        # Save the object because it has changed unless save is False
+        if save:
+            self.save()
 
     _save_FIELD_file.alters_data = True
 
diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py
index fe317ac24f..136ce31b8b 100644
--- a/django/db/models/fields/__init__.py
+++ b/django/db/models/fields/__init__.py
@@ -10,6 +10,10 @@ from django.utils.itercompat import tee
 from django.utils.text import capfirst
 from django.utils.translation import gettext, gettext_lazy
 import datetime, os, time
+try:
+    import decimal
+except ImportError:
+    from django.utils import _decimal as decimal    # for Python 2.3
 
 class NOT_PROVIDED:
     pass
@@ -67,7 +71,7 @@ class Field(object):
 
     def __init__(self, verbose_name=None, name=None, primary_key=False,
         maxlength=None, unique=False, blank=False, null=False, db_index=False,
-        core=False, rel=None, default=NOT_PROVIDED, editable=True,
+        core=False, rel=None, default=NOT_PROVIDED, editable=True, serialize=True,
         prepopulate_from=None, unique_for_date=None, unique_for_month=None,
         unique_for_year=None, validator_list=None, choices=None, radio_admin=None,
         help_text='', db_column=None):
@@ -78,6 +82,7 @@ class Field(object):
         self.blank, self.null = blank, null
         self.core, self.rel, self.default = core, rel, default
         self.editable = editable
+        self.serialize = serialize
         self.validator_list = validator_list or []
         self.prepopulate_from = prepopulate_from
         self.unique_for_date, self.unique_for_month = unique_for_date, unique_for_month
@@ -164,7 +169,7 @@ class Field(object):
 
     def get_db_prep_lookup(self, lookup_type, value):
         "Returns field's value prepared for database lookup."
-        if lookup_type in ('exact', 'gt', 'gte', 'lt', 'lte', 'year', 'month', 'day', 'search'):
+        if lookup_type in ('exact', 'gt', 'gte', 'lt', 'lte', 'month', 'day', 'search'):
             return [value]
         elif lookup_type in ('range', 'in'):
             return value
@@ -178,7 +183,13 @@ class Field(object):
             return ["%%%s" % prep_for_like_query(value)]
         elif lookup_type == 'isnull':
             return []
-        raise TypeError, "Field has invalid lookup: %s" % lookup_type
+        elif lookup_type == 'year':
+            try:
+                value = int(value)
+            except ValueError:
+                raise ValueError("The __year lookup type requires an integer argument")
+            return ['%s-01-01 00:00:00' % value, '%s-12-31 23:59:59.999999' % value]
+        raise TypeError("Field has invalid lookup: %s" % lookup_type)
 
     def has_default(self):
         "Returns a boolean of whether this field has a default value."
@@ -334,10 +345,17 @@ class Field(object):
             return self._choices
     choices = property(_get_choices)
 
-    def formfield(self):
+    def formfield(self, form_class=forms.CharField, **kwargs):
         "Returns a django.newforms.Field instance for this database Field."
-        # TODO: This is just a temporary default during development.
-        return forms.CharField(required=not self.blank, label=capfirst(self.verbose_name))
+        defaults = {'required': not self.blank, 'label': capfirst(self.verbose_name), 'help_text': self.help_text}
+        if self.choices:
+            defaults['widget'] = forms.Select(choices=self.get_choices())
+        defaults.update(kwargs)
+        return form_class(**defaults)
+
+    def value_from_object(self, obj):
+        "Returns the value of this field in the given model instance."
+        return getattr(obj, self.attname)
 
 class AutoField(Field):
     empty_strings_allowed = False
@@ -375,7 +393,7 @@ class AutoField(Field):
         super(AutoField, self).contribute_to_class(cls, name)
         cls._meta.has_auto_field = True
 
-    def formfield(self):
+    def formfield(self, **kwargs):
         return None
 
 class BooleanField(Field):
@@ -392,8 +410,10 @@ class BooleanField(Field):
     def get_manipulator_field_objs(self):
         return [oldforms.CheckboxField]
 
-    def formfield(self):
-        return forms.BooleanField(required=not self.blank, label=capfirst(self.verbose_name))
+    def formfield(self, **kwargs):
+        defaults = {'form_class': forms.BooleanField}
+        defaults.update(kwargs)
+        return super(BooleanField, self).formfield(**defaults)
 
 class CharField(Field):
     def get_manipulator_field_objs(self):
@@ -409,8 +429,10 @@ class CharField(Field):
                 raise validators.ValidationError, gettext_lazy("This field cannot be null.")
         return str(value)
 
-    def formfield(self):
-        return forms.CharField(max_length=self.maxlength, required=not self.blank, label=capfirst(self.verbose_name))
+    def formfield(self, **kwargs):
+        defaults = {'max_length': self.maxlength}
+        defaults.update(kwargs)
+        return super(CharField, self).formfield(**defaults)
 
 # TODO: Maybe move this into contrib, because it's specialized.
 class CommaSeparatedIntegerField(CharField):
@@ -428,6 +450,8 @@ class DateField(Field):
         Field.__init__(self, verbose_name, name, **kwargs)
 
     def to_python(self, value):
+        if value is None:
+            return value
         if isinstance(value, datetime.datetime):
             return value.date()
         if isinstance(value, datetime.date):
@@ -479,15 +503,19 @@ class DateField(Field):
     def get_manipulator_field_objs(self):
         return [oldforms.DateField]
 
-    def flatten_data(self, follow, obj = None):
+    def flatten_data(self, follow, obj=None):
         val = self._get_val_from_obj(obj)
         return {self.attname: (val is not None and val.strftime("%Y-%m-%d") or '')}
 
-    def formfield(self):
-        return forms.DateField(required=not self.blank, label=capfirst(self.verbose_name))
+    def formfield(self, **kwargs):
+        defaults = {'form_class': forms.DateField}
+        defaults.update(kwargs)
+        return super(DateField, self).formfield(**defaults)
 
 class DateTimeField(DateField):
     def to_python(self, value):
+        if value is None:
+            return value
         if isinstance(value, datetime.datetime):
             return value
         if isinstance(value, datetime.date):
@@ -544,8 +572,69 @@ class DateTimeField(DateField):
         return {date_field: (val is not None and val.strftime("%Y-%m-%d") or ''),
                 time_field: (val is not None and val.strftime("%H:%M:%S") or '')}
 
-    def formfield(self):
-        return forms.DateTimeField(required=not self.blank, label=capfirst(self.verbose_name))
+    def formfield(self, **kwargs):
+        defaults = {'form_class': forms.DateTimeField}
+        defaults.update(kwargs)
+        return super(DateTimeField, self).formfield(**defaults)
+
+class DecimalField(Field):
+    empty_strings_allowed = False
+    def __init__(self, verbose_name=None, name=None, max_digits=None, decimal_places=None, **kwargs):
+        self.max_digits, self.decimal_places = max_digits, decimal_places
+        Field.__init__(self, verbose_name, name, **kwargs)
+
+    def to_python(self, value):
+        if value is None:
+            return value
+        try:
+            return decimal.Decimal(value)
+        except decimal.InvalidOperation:
+            raise validators.ValidationError, gettext("This value must be a decimal number.")
+
+    def _format(self, value):
+        if isinstance(value, basestring):
+            return value
+        else:
+            return self.format_number(value)
+
+    def format_number(self, value):
+        """
+        Formats a number into a string with the requisite number of digits and
+        decimal places.
+        """
+        num_chars = self.max_digits
+        # Allow for a decimal point
+        if self.decimal_places > 0:
+            num_chars += 1
+        # Allow for a minus sign
+        if value < 0:
+            num_chars += 1
+
+        return "%.*f" % (self.decimal_places, value)
+
+    def get_db_prep_save(self, value):
+        if value is not None:
+            value = self._format(value)
+        return super(DecimalField, self).get_db_prep_save(value)
+
+    def get_db_prep_lookup(self, lookup_type, value):
+        if lookup_type == 'range':
+            value = [self._format(v) for v in value]
+        else:
+            value = self._format(value)
+        return super(DecimalField, self).get_db_prep_lookup(lookup_type, value)
+
+    def get_manipulator_field_objs(self):
+        return [curry(oldforms.DecimalField, max_digits=self.max_digits, decimal_places=self.decimal_places)]
+
+    def formfield(self, **kwargs):
+        defaults = {
+            'max_digits': self.max_digits,
+            'decimal_places': self.decimal_places,
+            'form_class': forms.DecimalField,
+        }
+        defaults.update(kwargs)
+        return super(DecimalField, self).formfield(**defaults)
 
 class EmailField(CharField):
     def __init__(self, *args, **kwargs):
@@ -561,8 +650,10 @@ class EmailField(CharField):
     def validate(self, field_data, all_data):
         validators.isValidEmail(field_data, all_data)
 
-    def formfield(self):
-        return forms.EmailField(required=not self.blank, label=capfirst(self.verbose_name))
+    def formfield(self, **kwargs):
+        defaults = {'form_class': forms.EmailField}
+        defaults.update(kwargs)
+        return super(EmailField, self).formfield(**defaults)
 
 class FileField(Field):
     def __init__(self, verbose_name=None, name=None, upload_to='', **kwargs):
@@ -610,7 +701,7 @@ class FileField(Field):
         setattr(cls, 'get_%s_filename' % self.name, curry(cls._get_FIELD_filename, field=self))
         setattr(cls, 'get_%s_url' % self.name, curry(cls._get_FIELD_url, field=self))
         setattr(cls, 'get_%s_size' % self.name, curry(cls._get_FIELD_size, field=self))
-        setattr(cls, 'save_%s_file' % self.name, lambda instance, filename, raw_contents: instance._save_FIELD_file(self, filename, raw_contents))
+        setattr(cls, 'save_%s_file' % self.name, lambda instance, filename, raw_contents, save=True: instance._save_FIELD_file(self, filename, raw_contents, save))
         dispatcher.connect(self.delete_file, signal=signals.post_delete, sender=cls)
 
     def delete_file(self, instance):
@@ -628,14 +719,14 @@ class FileField(Field):
     def get_manipulator_field_names(self, name_prefix):
         return [name_prefix + self.name + '_file', name_prefix + self.name]
 
-    def save_file(self, new_data, new_object, original_object, change, rel):
+    def save_file(self, new_data, new_object, original_object, change, rel, save=True):
         upload_field_name = self.get_manipulator_field_names('')[0]
         if new_data.get(upload_field_name, False):
             func = getattr(new_object, 'save_%s_file' % self.name)
             if rel:
-                func(new_data[upload_field_name][0]["filename"], new_data[upload_field_name][0]["content"])
+                func(new_data[upload_field_name][0]["filename"], new_data[upload_field_name][0]["content"], save)
             else:
-                func(new_data[upload_field_name]["filename"], new_data[upload_field_name]["content"])
+                func(new_data[upload_field_name]["filename"], new_data[upload_field_name]["content"], save)
 
     def get_directory_name(self):
         return os.path.normpath(datetime.datetime.now().strftime(self.upload_to))
@@ -655,12 +746,14 @@ class FilePathField(Field):
 
 class FloatField(Field):
     empty_strings_allowed = False
-    def __init__(self, verbose_name=None, name=None, max_digits=None, decimal_places=None, **kwargs):
-        self.max_digits, self.decimal_places = max_digits, decimal_places
-        Field.__init__(self, verbose_name, name, **kwargs)
 
     def get_manipulator_field_objs(self):
-        return [curry(oldforms.FloatField, max_digits=self.max_digits, decimal_places=self.decimal_places)]
+        return [oldforms.FloatField]
+
+    def formfield(self, **kwargs):
+        defaults = {'form_class': forms.FloatField}
+        defaults.update(kwargs)
+        return super(FloatField, self).formfield(**defaults)
 
 class ImageField(FileField):
     def __init__(self, verbose_name=None, name=None, width_field=None, height_field=None, **kwargs):
@@ -679,12 +772,12 @@ class ImageField(FileField):
         if not self.height_field:
             setattr(cls, 'get_%s_height' % self.name, curry(cls._get_FIELD_height, field=self))
 
-    def save_file(self, new_data, new_object, original_object, change, rel):
-        FileField.save_file(self, new_data, new_object, original_object, change, rel)
+    def save_file(self, new_data, new_object, original_object, change, rel, save=True):
+        FileField.save_file(self, new_data, new_object, original_object, change, rel, save)
         # If the image has height and/or width field(s) and they haven't
         # changed, set the width and/or height field(s) back to their original
         # values.
-        if change and (self.width_field or self.height_field):
+        if change and (self.width_field or self.height_field) and save:
             if self.width_field:
                 setattr(new_object, self.width_field, getattr(original_object, self.width_field))
             if self.height_field:
@@ -696,8 +789,10 @@ class IntegerField(Field):
     def get_manipulator_field_objs(self):
         return [oldforms.IntegerField]
 
-    def formfield(self):
-        return forms.IntegerField(required=not self.blank, label=capfirst(self.verbose_name))
+    def formfield(self, **kwargs):
+        defaults = {'form_class': forms.IntegerField}
+        defaults.update(kwargs)
+        return super(IntegerField, self).formfield(**defaults)
 
 class IPAddressField(Field):
     def __init__(self, *args, **kwargs):
@@ -715,6 +810,13 @@ class NullBooleanField(Field):
         kwargs['null'] = True
         Field.__init__(self, *args, **kwargs)
 
+    def to_python(self, value):
+        if value in (None, True, False): return value
+        if value in ('None'): return None
+        if value in ('t', 'True', '1'): return True
+        if value in ('f', 'False', '0'): return False
+        raise validators.ValidationError, gettext("This value must be either None, True or False.")
+
     def get_manipulator_field_objs(self):
         return [oldforms.NullBooleanField]
 
@@ -725,6 +827,12 @@ class PhoneNumberField(IntegerField):
     def validate(self, field_data, all_data):
         validators.isValidPhone(field_data, all_data)
 
+    def formfield(self, **kwargs):
+        from django.contrib.localflavor.us.forms import USPhoneNumberField
+        defaults = {'form_class': USPhoneNumberField}
+        defaults.update(kwargs)
+        return super(PhoneNumberField, self).formfield(**defaults)
+
 class PositiveIntegerField(IntegerField):
     def get_manipulator_field_objs(self):
         return [oldforms.PositiveIntegerField]
@@ -738,7 +846,7 @@ class SlugField(Field):
         kwargs['maxlength'] = kwargs.get('maxlength', 50)
         kwargs.setdefault('validator_list', []).append(validators.isSlug)
         # Set db_index=True unless it's been set manually.
-        if not kwargs.has_key('db_index'):
+        if 'db_index' not in kwargs:
             kwargs['db_index'] = True
         Field.__init__(self, *args, **kwargs)
 
@@ -753,6 +861,11 @@ class TextField(Field):
     def get_manipulator_field_objs(self):
         return [oldforms.LargeTextField]
 
+    def formfield(self, **kwargs):
+        defaults = {'widget': forms.Textarea}
+        defaults.update(kwargs)
+        return super(TextField, self).formfield(**defaults)
+
 class TimeField(Field):
     empty_strings_allowed = False
     def __init__(self, verbose_name=None, name=None, auto_now=False, auto_now_add=False, **kwargs):
@@ -781,7 +894,7 @@ class TimeField(Field):
         if value is not None:
             # MySQL will throw a warning if microseconds are given, because it
             # doesn't support microseconds.
-            if settings.DATABASE_ENGINE == 'mysql':
+            if settings.DATABASE_ENGINE == 'mysql' and hasattr(value, 'microsecond'):
                 value = value.replace(microsecond=0)
             value = str(value)
         return Field.get_db_prep_save(self, value)
@@ -793,26 +906,40 @@ class TimeField(Field):
         val = self._get_val_from_obj(obj)
         return {self.attname: (val is not None and val.strftime("%H:%M:%S") or '')}
 
-    def formfield(self):
-        return forms.TimeField(required=not self.blank, label=capfirst(self.verbose_name))
+    def formfield(self, **kwargs):
+        defaults = {'form_class': forms.TimeField}
+        defaults.update(kwargs)
+        return super(TimeField, self).formfield(**defaults)
 
-class URLField(Field):
+class URLField(CharField):
     def __init__(self, verbose_name=None, name=None, verify_exists=True, **kwargs):
+        kwargs['maxlength'] = kwargs.get('maxlength', 200)
         if verify_exists:
             kwargs.setdefault('validator_list', []).append(validators.isExistingURL)
         self.verify_exists = verify_exists
-        Field.__init__(self, verbose_name, name, **kwargs)
+        CharField.__init__(self, verbose_name, name, **kwargs)
 
     def get_manipulator_field_objs(self):
         return [oldforms.URLField]
 
-    def formfield(self):
-        return forms.URLField(required=not self.blank, verify_exists=self.verify_exists, label=capfirst(self.verbose_name))
+    def get_internal_type(self):
+        return "CharField"
+
+    def formfield(self, **kwargs):
+        defaults = {'form_class': forms.URLField, 'verify_exists': self.verify_exists}
+        defaults.update(kwargs)
+        return super(URLField, self).formfield(**defaults)
 
 class USStateField(Field):
     def get_manipulator_field_objs(self):
         return [oldforms.USStateField]
 
+    def formfield(self, **kwargs):
+        from django.contrib.localflavor.us.forms import USStateSelect
+        defaults = {'widget': USStateSelect}
+        defaults.update(kwargs)
+        return super(USStateField, self).formfield(**defaults)
+
 class XMLField(TextField):
     def __init__(self, verbose_name=None, name=None, schema_path=None, **kwargs):
         self.schema_path = schema_path
diff --git a/django/db/models/fields/generic.py b/django/db/models/fields/generic.py
deleted file mode 100644
index 1ad8346e42..0000000000
--- a/django/db/models/fields/generic.py
+++ /dev/null
@@ -1,259 +0,0 @@
-"""
-Classes allowing "generic" relations through ContentType and object-id fields.
-"""
-
-from django import oldforms
-from django.core.exceptions import ObjectDoesNotExist
-from django.db import backend
-from django.db.models import signals
-from django.db.models.fields.related import RelatedField, Field, ManyToManyRel
-from django.db.models.loading import get_model
-from django.dispatch import dispatcher
-from django.utils.functional import curry
-
-class GenericForeignKey(object):
-    """
-    Provides a generic relation to any object through content-type/object-id
-    fields.
-    """
-    
-    def __init__(self, ct_field="content_type", fk_field="object_id"):
-        self.ct_field = ct_field
-        self.fk_field = fk_field
-        
-    def contribute_to_class(self, cls, name):
-        # Make sure the fields exist (these raise FieldDoesNotExist, 
-        # which is a fine error to raise here)
-        self.name = name
-        self.model = cls
-        self.cache_attr = "_%s_cache" % name
-        
-        # For some reason I don't totally understand, using weakrefs here doesn't work.
-        dispatcher.connect(self.instance_pre_init, signal=signals.pre_init, sender=cls, weak=False)
-
-        # Connect myself as the descriptor for this field
-        setattr(cls, name, self)
-
-    def instance_pre_init(self, signal, sender, args, kwargs):
-        # Handle initalizing an object with the generic FK instaed of 
-        # content-type/object-id fields.        
-        if kwargs.has_key(self.name):
-            value = kwargs.pop(self.name)
-            kwargs[self.ct_field] = self.get_content_type(value)
-            kwargs[self.fk_field] = value._get_pk_val()
-            
-    def get_content_type(self, obj):
-        # Convenience function using get_model avoids a circular import when using this model
-        ContentType = get_model("contenttypes", "contenttype")
-        return ContentType.objects.get_for_model(obj)
-        
-    def __get__(self, instance, instance_type=None):
-        if instance is None:
-            raise AttributeError, "%s must be accessed via instance" % self.name
-
-        try:
-            return getattr(instance, self.cache_attr)
-        except AttributeError:
-            rel_obj = None
-            ct = getattr(instance, self.ct_field)
-            if ct:
-                try:
-                    rel_obj = ct.get_object_for_this_type(pk=getattr(instance, self.fk_field))
-                except ObjectDoesNotExist:
-                    pass
-            setattr(instance, self.cache_attr, rel_obj)
-            return rel_obj
-
-    def __set__(self, instance, value):
-        if instance is None:
-            raise AttributeError, "%s must be accessed via instance" % self.related.opts.object_name
-
-        ct = None
-        fk = None
-        if value is not None:
-            ct = self.get_content_type(value)
-            fk = value._get_pk_val()
-
-        setattr(instance, self.ct_field, ct)
-        setattr(instance, self.fk_field, fk)
-        setattr(instance, self.cache_attr, value)
-    
-class GenericRelation(RelatedField, Field):
-    """Provides an accessor to generic related objects (i.e. comments)"""
-
-    def __init__(self, to, **kwargs):
-        kwargs['verbose_name'] = kwargs.get('verbose_name', None)
-        kwargs['rel'] = GenericRel(to, 
-                            related_name=kwargs.pop('related_name', None),
-                            limit_choices_to=kwargs.pop('limit_choices_to', None),
-                            symmetrical=kwargs.pop('symmetrical', True))
-                            
-        # Override content-type/object-id field names on the related class
-        self.object_id_field_name = kwargs.pop("object_id_field", "object_id")
-        self.content_type_field_name = kwargs.pop("content_type_field", "content_type")                
-        
-        kwargs['blank'] = True
-        kwargs['editable'] = False
-        Field.__init__(self, **kwargs)
-
-    def get_manipulator_field_objs(self):
-        choices = self.get_choices_default()
-        return [curry(oldforms.SelectMultipleField, size=min(max(len(choices), 5), 15), choices=choices)]
-
-    def get_choices_default(self):
-        return Field.get_choices(self, include_blank=False)
-
-    def flatten_data(self, follow, obj = None):
-        new_data = {}
-        if obj:
-            instance_ids = [instance._get_pk_val() for instance in getattr(obj, self.name).all()]
-            new_data[self.name] = instance_ids
-        return new_data
-
-    def m2m_db_table(self):
-        return self.rel.to._meta.db_table
-
-    def m2m_column_name(self):
-        return self.object_id_field_name
-        
-    def m2m_reverse_name(self):
-        return self.object_id_field_name
-
-    def contribute_to_class(self, cls, name):
-        super(GenericRelation, self).contribute_to_class(cls, name)
-
-        # Save a reference to which model this class is on for future use
-        self.model = cls
-
-        # Add the descriptor for the m2m relation
-        setattr(cls, self.name, ReverseGenericRelatedObjectsDescriptor(self))
-
-    def contribute_to_related_class(self, cls, related):
-        pass
-        
-    def set_attributes_from_rel(self):
-        pass
-
-    def get_internal_type(self):
-        return "ManyToManyField"
-        
-class ReverseGenericRelatedObjectsDescriptor(object):
-    """
-    This class provides the functionality that makes the related-object
-    managers available as attributes on a model class, for fields that have
-    multiple "remote" values and have a GenericRelation defined in their model
-    (rather than having another model pointed *at* them). In the example
-    "article.publications", the publications attribute is a
-    ReverseGenericRelatedObjectsDescriptor instance.
-    """
-    def __init__(self, field):
-        self.field = field
-
-    def __get__(self, instance, instance_type=None):
-        if instance is None:
-            raise AttributeError, "Manager must be accessed via instance"
-
-        # This import is done here to avoid circular import importing this module
-        from django.contrib.contenttypes.models import ContentType
-
-        # Dynamically create a class that subclasses the related model's
-        # default manager.
-        rel_model = self.field.rel.to
-        superclass = rel_model._default_manager.__class__
-        RelatedManager = create_generic_related_manager(superclass)
-
-        manager = RelatedManager(
-            model = rel_model,
-            instance = instance,
-            symmetrical = (self.field.rel.symmetrical and instance.__class__ == rel_model),
-            join_table = backend.quote_name(self.field.m2m_db_table()),
-            source_col_name = backend.quote_name(self.field.m2m_column_name()),
-            target_col_name = backend.quote_name(self.field.m2m_reverse_name()),
-            content_type = ContentType.objects.get_for_model(self.field.model),
-            content_type_field_name = self.field.content_type_field_name,
-            object_id_field_name = self.field.object_id_field_name
-        )
-
-        return manager
-
-    def __set__(self, instance, value):
-        if instance is None:
-            raise AttributeError, "Manager must be accessed via instance"
-
-        manager = self.__get__(instance)
-        manager.clear()
-        for obj in value:
-            manager.add(obj)
-
-def create_generic_related_manager(superclass):
-    """
-    Factory function for a manager that subclasses 'superclass' (which is a
-    Manager) and adds behavior for generic related objects.
-    """
-    
-    class GenericRelatedObjectManager(superclass):
-        def __init__(self, model=None, core_filters=None, instance=None, symmetrical=None,
-                     join_table=None, source_col_name=None, target_col_name=None, content_type=None,
-                     content_type_field_name=None, object_id_field_name=None):
-            
-            super(GenericRelatedObjectManager, self).__init__()
-            self.core_filters = core_filters or {}
-            self.model = model
-            self.content_type = content_type
-            self.symmetrical = symmetrical
-            self.instance = instance
-            self.join_table = join_table
-            self.join_table = model._meta.db_table
-            self.source_col_name = source_col_name
-            self.target_col_name = target_col_name
-            self.content_type_field_name = content_type_field_name
-            self.object_id_field_name = object_id_field_name
-            self.pk_val = self.instance._get_pk_val()
-                        
-        def get_query_set(self):
-            query = {
-                '%s__pk' % self.content_type_field_name : self.content_type.id, 
-                '%s__exact' % self.object_id_field_name : self.pk_val,
-            }
-            return superclass.get_query_set(self).filter(**query)
-
-        def add(self, *objs):
-            for obj in objs:
-                setattr(obj, self.content_type_field_name, self.content_type)
-                setattr(obj, self.object_id_field_name, self.pk_val)
-                obj.save()
-        add.alters_data = True
-
-        def remove(self, *objs):
-            for obj in objs:
-                obj.delete()
-        remove.alters_data = True
-
-        def clear(self):
-            for obj in self.all():
-                obj.delete()
-        clear.alters_data = True
-
-        def create(self, **kwargs):
-            kwargs[self.content_type_field_name] = self.content_type
-            kwargs[self.object_id_field_name] = self.pk_val
-            obj = self.model(**kwargs)
-            obj.save()
-            return obj
-        create.alters_data = True
-
-    return GenericRelatedObjectManager
-
-class GenericRel(ManyToManyRel):
-    def __init__(self, to, related_name=None, limit_choices_to=None, symmetrical=True):
-        self.to = to
-        self.num_in_admin = 0
-        self.related_name = related_name
-        self.filter_interface = None
-        self.limit_choices_to = limit_choices_to or {}
-        self.edit_inline = False
-        self.raw_id_admin = False
-        self.symmetrical = symmetrical
-        self.multiple = True
-        assert not (self.raw_id_admin and self.filter_interface), \
-            "Generic relations may not use both raw_id_admin and filter_interface"
diff --git a/django/db/models/fields/related.py b/django/db/models/fields/related.py
index 797ef05be1..0739d0461a 100644
--- a/django/db/models/fields/related.py
+++ b/django/db/models/fields/related.py
@@ -2,10 +2,12 @@ from django.db import backend, transaction
 from django.db.models import signals, get_model
 from django.db.models.fields import AutoField, Field, IntegerField, get_ul_class
 from django.db.models.related import RelatedObject
+from django.utils.text import capfirst
 from django.utils.translation import gettext_lazy, string_concat, ngettext
 from django.utils.functional import curry
 from django.core import validators
 from django import oldforms
+from django import newforms as forms
 from django.dispatch import dispatcher
 
 # For Python 2.3
@@ -314,18 +316,20 @@ def create_many_related_manager(superclass):
             # join_table: name of the m2m link table
             # source_col_name: the PK colname in join_table for the source object
             # target_col_name: the PK colname in join_table for the target object
-            # *objs - objects to add
+            # *objs - objects to add. Either object instances, or primary keys of object instances.
             from django.db import connection
 
             # If there aren't any objects, there is nothing to do.
             if objs:
                 # Check that all the objects are of the right type
+                new_ids = set()
                 for obj in objs:
-                    if not isinstance(obj, self.model):
-                        raise ValueError, "objects to add() must be %s instances" % self.model._meta.object_name
+                    if isinstance(obj, self.model):
+                        new_ids.add(obj._get_pk_val())
+                    else:
+                        new_ids.add(obj)
                 # Add the newly created or already existing objects to the join table.
                 # First find out which items are already added, to avoid adding them twice
-                new_ids = set([obj._get_pk_val() for obj in objs])
                 cursor = connection.cursor()
                 cursor.execute("SELECT %s FROM %s WHERE %s = %%s AND %s IN (%s)" % \
                     (target_col_name, self.join_table, source_col_name,
@@ -352,14 +356,16 @@ def create_many_related_manager(superclass):
             # If there aren't any objects, there is nothing to do.
             if objs:
                 # Check that all the objects are of the right type
+                old_ids = set()
                 for obj in objs:
-                    if not isinstance(obj, self.model):
-                        raise ValueError, "objects to remove() must be %s instances" % self.model._meta.object_name
+                    if isinstance(obj, self.model):
+                        old_ids.add(obj._get_pk_val())
+                    else:
+                        old_ids.add(obj)
                 # Remove the specified objects from the join table
-                old_ids = set([obj._get_pk_val() for obj in objs])
                 cursor = connection.cursor()
                 cursor.execute("DELETE FROM %s WHERE %s = %%s AND %s IN (%s)" % \
-                    (self.join_table, source_col_name, 
+                    (self.join_table, source_col_name,
                     target_col_name, ",".join(['%s'] * len(old_ids))),
                     [self._pk_val] + list(old_ids))
                 transaction.commit_unless_managed()
@@ -468,7 +474,7 @@ class ForeignKey(RelatedField, Field):
             to_field = to_field or to._meta.pk.name
         kwargs['verbose_name'] = kwargs.get('verbose_name', '')
 
-        if kwargs.has_key('edit_inline_type'):
+        if 'edit_inline_type' in kwargs:
             import warnings
             warnings.warn("edit_inline_type is deprecated. Use edit_inline instead.")
             kwargs['edit_inline'] = kwargs.pop('edit_inline_type')
@@ -546,6 +552,11 @@ class ForeignKey(RelatedField, Field):
     def contribute_to_related_class(self, cls, related):
         setattr(cls, related.get_accessor_name(), ForeignRelatedObjectsDescriptor(related))
 
+    def formfield(self, **kwargs):
+        defaults = {'form_class': forms.ModelChoiceField, 'queryset': self.rel.to._default_manager.all()}
+        defaults.update(kwargs)
+        return super(ForeignKey, self).formfield(**defaults)
+
 class OneToOneField(RelatedField, IntegerField):
     def __init__(self, to, to_field=None, **kwargs):
         try:
@@ -556,7 +567,7 @@ class OneToOneField(RelatedField, IntegerField):
             to_field = to_field or to._meta.pk.name
         kwargs['verbose_name'] = kwargs.get('verbose_name', '')
 
-        if kwargs.has_key('edit_inline_type'):
+        if 'edit_inline_type' in kwargs:
             import warnings
             warnings.warn("edit_inline_type is deprecated. Use edit_inline instead.")
             kwargs['edit_inline'] = kwargs.pop('edit_inline_type')
@@ -607,6 +618,11 @@ class OneToOneField(RelatedField, IntegerField):
         if not cls._meta.one_to_one_field:
             cls._meta.one_to_one_field = self
 
+    def formfield(self, **kwargs):
+        defaults = {'form_class': forms.ModelChoiceField, 'queryset': self.rel.to._default_manager.all()}
+        defaults.update(kwargs)
+        return super(OneToOneField, self).formfield(**defaults)
+
 class ManyToManyField(RelatedField, Field):
     def __init__(self, to, **kwargs):
         kwargs['verbose_name'] = kwargs.get('verbose_name', None)
@@ -617,6 +633,7 @@ class ManyToManyField(RelatedField, Field):
             limit_choices_to=kwargs.pop('limit_choices_to', None),
             raw_id_admin=kwargs.pop('raw_id_admin', False),
             symmetrical=kwargs.pop('symmetrical', True))
+        self.db_table = kwargs.pop('db_table', None)
         if kwargs["rel"].raw_id_admin:
             kwargs.setdefault("validator_list", []).append(self.isValidIDList)
         Field.__init__(self, **kwargs)
@@ -639,7 +656,10 @@ class ManyToManyField(RelatedField, Field):
 
     def _get_m2m_db_table(self, opts):
         "Function that can be curried to provide the m2m table name for this relation"
-        return '%s_%s' % (opts.db_table, self.name)
+        if self.db_table:
+            return self.db_table
+        else:
+            return '%s_%s' % (opts.db_table, self.name)
 
     def _get_m2m_column_name(self, related):
         "Function that can be curried to provide the source column name for the m2m table"
@@ -713,6 +733,19 @@ class ManyToManyField(RelatedField, Field):
     def set_attributes_from_rel(self):
         pass
 
+    def value_from_object(self, obj):
+        "Returns the value of this field in the given model instance."
+        return getattr(obj, self.attname).all()
+
+    def formfield(self, **kwargs):
+        defaults = {'form_class': forms.ModelMultipleChoiceField, 'queryset': self.rel.to._default_manager.all()}
+        defaults.update(kwargs)
+        # If initial is passed in, it's a list of related objects, but the
+        # MultipleChoiceField takes a list of IDs.
+        if defaults.get('initial') is not None:
+            defaults['initial'] = [i._get_pk_val() for i in defaults['initial']]
+        return super(ManyToManyField, self).formfield(**defaults)
+
 class ManyToOneRel(object):
     def __init__(self, to, field_name, num_in_admin=3, min_num_in_admin=None,
         max_num_in_admin=None, num_extra_on_change=1, edit_inline=False,
diff --git a/django/db/models/loading.py b/django/db/models/loading.py
index f4aff2438b..224f5e8451 100644
--- a/django/db/models/loading.py
+++ b/django/db/models/loading.py
@@ -103,7 +103,7 @@ def register_models(app_label, *models):
         # in the _app_models dictionary
         model_name = model._meta.object_name.lower()
         model_dict = _app_models.setdefault(app_label, {})
-        if model_dict.has_key(model_name):
+        if model_name in model_dict:
             # The same model may be imported via different paths (e.g.
             # appname.models and project.appname.models). We use the source
             # filename as a means to detect identity.
diff --git a/django/db/models/manager.py b/django/db/models/manager.py
index 6005874516..b60eed262a 100644
--- a/django/db/models/manager.py
+++ b/django/db/models/manager.py
@@ -1,4 +1,4 @@
-from django.db.models.query import QuerySet
+from django.db.models.query import QuerySet, EmptyQuerySet
 from django.dispatch import dispatcher
 from django.db.models import signals
 from django.db.models.fields import FieldDoesNotExist
@@ -41,12 +41,18 @@ class Manager(object):
     #######################
     # PROXIES TO QUERYSET #
     #######################
+    
+    def get_empty_query_set(self):
+        return EmptyQuerySet(self.model)
 
     def get_query_set(self):
         """Returns a new QuerySet object.  Subclasses can override this method
         to easily customise the behaviour of the Manager.
         """
         return QuerySet(self.model)
+    
+    def none(self):
+        return self.get_empty_query_set()
 
     def all(self):
         return self.get_query_set()
diff --git a/django/db/models/manipulators.py b/django/db/models/manipulators.py
index e9dfa7037c..d5fc5f725e 100644
--- a/django/db/models/manipulators.py
+++ b/django/db/models/manipulators.py
@@ -96,14 +96,16 @@ class AutomaticManipulator(oldforms.Manipulator):
         if self.change:
             params[self.opts.pk.attname] = self.obj_key
 
-        # First, save the basic object itself.
+        # First, create the basic object itself.
         new_object = self.model(**params)
-        new_object.save()
 
-        # Now that the object's been saved, save any uploaded files.
+        # Now that the object's been created, save any uploaded files.
         for f in self.opts.fields:
             if isinstance(f, FileField):
-                f.save_file(new_data, new_object, self.change and self.original_object or None, self.change, rel=False)
+                f.save_file(new_data, new_object, self.change and self.original_object or None, self.change, rel=False, save=False)
+
+        # Now save the object
+        new_object.save()
 
         # Calculate which primary fields have changed.
         if self.change:
diff --git a/django/db/models/options.py b/django/db/models/options.py
index ee253ff451..556168e7d0 100644
--- a/django/db/models/options.py
+++ b/django/db/models/options.py
@@ -85,6 +85,7 @@ class Options(object):
             self.fields.insert(bisect(self.fields, field), field)
             if not self.pk and field.primary_key:
                 self.pk = field
+                field.serialize = False
 
     def __repr__(self):
         return '<Options for %s>' % self.object_name
@@ -140,7 +141,7 @@ class Options(object):
     def get_follow(self, override=None):
         follow = {}
         for f in self.fields + self.many_to_many + self.get_all_related_objects():
-            if override and override.has_key(f.name):
+            if override and f.name in override:
                 child_override = override[f.name]
             else:
                 child_override = None
@@ -182,7 +183,7 @@ class Options(object):
         # TODO: follow
         if not hasattr(self, '_field_types'):
             self._field_types = {}
-        if not self._field_types.has_key(field_type):
+        if field_type not in self._field_types:
             try:
                 # First check self.fields.
                 for f in self.fields:
diff --git a/django/db/models/query.py b/django/db/models/query.py
index 53ed63ae5b..a6e702be18 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -1,8 +1,9 @@
 from django.db import backend, connection, transaction
 from django.db.models.fields import DateField, FieldDoesNotExist
-from django.db.models import signals
+from django.db.models import signals, loading
 from django.dispatch import dispatcher
 from django.utils.datastructures import SortedDict
+from django.contrib.contenttypes import generic
 import operator
 import re
 
@@ -25,6 +26,9 @@ QUERY_TERMS = (
 # Larger values are slightly faster at the expense of more storage space.
 GET_ITERATOR_CHUNK_SIZE = 100
 
+class EmptyResultSet(Exception):
+    pass
+
 ####################
 # HELPER FUNCTIONS #
 ####################
@@ -80,6 +84,7 @@ class QuerySet(object):
         self._filters = Q()
         self._order_by = None        # Ordering, e.g. ('date', '-name'). If None, use model's ordering.
         self._select_related = False # Whether to fill cache for related objects.
+        self._max_related_depth = 0  # Maximum "depth" for select_related
         self._distinct = False       # Whether the query should use SELECT DISTINCT.
         self._select = {}            # Dictionary of attname -> SQL.
         self._where = []             # List of extra WHERE clauses to use.
@@ -104,6 +109,8 @@ class QuerySet(object):
 
     def __getitem__(self, k):
         "Retrieve an item or slice from the set of results."
+        if not isinstance(k, (slice, int)):
+            raise TypeError
         assert (not isinstance(k, slice) and (k >= 0)) \
             or (isinstance(k, slice) and (k.start is None or k.start >= 0) and (k.stop is None or k.stop >= 0)), \
             "Negative indexing is not supported."
@@ -163,12 +170,16 @@ class QuerySet(object):
 
     def iterator(self):
         "Performs the SELECT database lookup of this QuerySet."
+        try:
+            select, sql, params = self._get_sql_clause()
+        except EmptyResultSet:
+            raise StopIteration
+
         # self._select is a dictionary, and dictionaries' key order is
         # undefined, so we convert it to a list of tuples.
         extra_select = self._select.items()
 
         cursor = connection.cursor()
-        select, sql, params = self._get_sql_clause()
         cursor.execute("SELECT " + (self._distinct and "DISTINCT " or "") + ",".join(select) + sql, params)
         fill_cache = self._select_related
         index_end = len(self.model._meta.fields)
@@ -178,7 +189,8 @@ class QuerySet(object):
                 raise StopIteration
             for row in rows:
                 if fill_cache:
-                    obj, index_end = get_cached_row(self.model, row, 0)
+                    obj, index_end = get_cached_row(klass=self.model, row=row,
+                                                    index_start=0, max_depth=self._max_related_depth)
                 else:
                     obj = self.model(*row[:index_end])
                 for i, k in enumerate(extra_select):
@@ -186,13 +198,31 @@ class QuerySet(object):
                 yield obj
 
     def count(self):
-        "Performs a SELECT COUNT() and returns the number of records as an integer."
+        """
+        Performs a SELECT COUNT() and returns the number of records as an
+        integer.
+
+        If the queryset is already cached (i.e. self._result_cache is set) this
+        simply returns the length of the cached results set to avoid multiple
+        SELECT COUNT(*) calls.
+        """
+        if self._result_cache is not None:
+            return len(self._result_cache)
+
         counter = self._clone()
         counter._order_by = ()
+        counter._select_related = False
+
+        offset = counter._offset
+        limit = counter._limit
         counter._offset = None
         counter._limit = None
-        counter._select_related = False
-        select, sql, params = counter._get_sql_clause()
+
+        try:
+            select, sql, params = counter._get_sql_clause()
+        except EmptyResultSet:
+            return 0
+
         cursor = connection.cursor()
         if self._distinct:
             id_col = "%s.%s" % (backend.quote_name(self.model._meta.db_table),
@@ -200,7 +230,16 @@ class QuerySet(object):
             cursor.execute("SELECT COUNT(DISTINCT(%s))" % id_col + sql, params)
         else:
             cursor.execute("SELECT COUNT(*)" + sql, params)
-        return cursor.fetchone()[0]
+        count = cursor.fetchone()[0]
+
+        # Apply any offset and limit constraints manually, since using LIMIT or
+        # OFFSET in SQL doesn't change the output of COUNT.
+        if offset:
+            count = max(0, count - offset)
+        if limit:
+            count = min(limit, count)
+
+        return count
 
     def get(self, *args, **kwargs):
         "Performs the SELECT and returns a single object matching the given keyword arguments."
@@ -359,9 +398,9 @@ class QuerySet(object):
         else:
             return self._filter_or_exclude(None, **filter_obj)
 
-    def select_related(self, true_or_false=True):
+    def select_related(self, true_or_false=True, depth=0):
         "Returns a new QuerySet instance with '_select_related' modified."
-        return self._clone(_select_related=true_or_false)
+        return self._clone(_select_related=true_or_false, _max_related_depth=depth)
 
     def order_by(self, *field_names):
         "Returns a new QuerySet instance with the ordering changed."
@@ -395,6 +434,7 @@ class QuerySet(object):
         c._filters = self._filters
         c._order_by = self._order_by
         c._select_related = self._select_related
+        c._max_related_depth = self._max_related_depth
         c._distinct = self._distinct
         c._select = self._select.copy()
         c._where = self._where[:]
@@ -448,7 +488,10 @@ class QuerySet(object):
 
         # Add additional tables and WHERE clauses based on select_related.
         if self._select_related:
-            fill_table_cache(opts, select, tables, where, opts.db_table, [opts.db_table])
+            fill_table_cache(opts, select, tables, where,
+                             old_prefix=opts.db_table,
+                             cache_tables_seen=[opts.db_table],
+                             max_depth=self._max_related_depth)
 
         # Add any additional SELECTs.
         if self._select:
@@ -509,22 +552,42 @@ class QuerySet(object):
         return select, " ".join(sql), params
 
 class ValuesQuerySet(QuerySet):
-    def iterator(self):
-        # select_related and select aren't supported in values().
+    def __init__(self, *args, **kwargs):
+        super(ValuesQuerySet, self).__init__(*args, **kwargs)
+        # select_related isn't supported in values().
         self._select_related = False
-        self._select = {}
+
+    def iterator(self):
+        try:
+            select, sql, params = self._get_sql_clause()
+        except EmptyResultSet:
+            raise StopIteration
 
         # self._fields is a list of field names to fetch.
         if self._fields:
-            columns = [self.model._meta.get_field(f, many_to_many=False).column for f in self._fields]
+            #columns = [self.model._meta.get_field(f, many_to_many=False).column for f in self._fields]
+            if not self._select:
+                columns = [self.model._meta.get_field(f, many_to_many=False).column for f in self._fields]
+            else:
+                columns = []
+                for f in self._fields:
+                    if f in [field.name for field in self.model._meta.fields]:
+                        columns.append( self.model._meta.get_field(f, many_to_many=False).column )
+                    elif not self._select.has_key( f ):
+                        raise FieldDoesNotExist, '%s has no field named %r' % ( self.model._meta.object_name, f )
+
             field_names = self._fields
         else: # Default to all fields.
             columns = [f.column for f in self.model._meta.fields]
             field_names = [f.attname for f in self.model._meta.fields]
 
-        cursor = connection.cursor()
-        select, sql, params = self._get_sql_clause()
         select = ['%s.%s' % (backend.quote_name(self.model._meta.db_table), backend.quote_name(c)) for c in columns]
+
+        # Add any additional SELECTs.
+        if self._select:
+            select.extend(['(%s) AS %s' % (quote_only_if_word(s[1]), backend.quote_name(s[0])) for s in self._select.items()])
+
+        cursor = connection.cursor()
         cursor.execute("SELECT " + (self._distinct and "DISTINCT " or "") + ",".join(select) + sql, params)
         while 1:
             rows = cursor.fetchmany(GET_ITERATOR_CHUNK_SIZE)
@@ -545,7 +608,12 @@ class DateQuerySet(QuerySet):
         if self._field.null:
             self._where.append('%s.%s IS NOT NULL' % \
                 (backend.quote_name(self.model._meta.db_table), backend.quote_name(self._field.column)))
-        select, sql, params = self._get_sql_clause()
+
+        try:
+            select, sql, params = self._get_sql_clause()
+        except EmptyResultSet:
+            raise StopIteration
+
         sql = 'SELECT %s %s GROUP BY 1 ORDER BY 1 %s' % \
             (backend.get_date_trunc_sql(self._kind, '%s.%s' % (backend.quote_name(self.model._meta.db_table),
             backend.quote_name(self._field.column))), sql, self._order)
@@ -563,6 +631,25 @@ class DateQuerySet(QuerySet):
         c._order = self._order
         return c
 
+class EmptyQuerySet(QuerySet):
+    def __init__(self, model=None):
+        super(EmptyQuerySet, self).__init__(model)
+        self._result_cache = []
+
+    def count(self):
+        return 0
+
+    def delete(self):
+        pass
+
+    def _clone(self, klass=None, **kwargs):
+        c = super(EmptyQuerySet, self)._clone(klass, **kwargs)
+        c._result_cache = []
+        return c
+
+    def _get_sql_clause(self):
+        raise EmptyResultSet
+
 class QOperator(object):
     "Base class for QAnd and QOr"
     def __init__(self, *args):
@@ -571,10 +658,14 @@ class QOperator(object):
     def get_sql(self, opts):
         joins, where, params = SortedDict(), [], []
         for val in self.args:
-            joins2, where2, params2 = val.get_sql(opts)
-            joins.update(joins2)
-            where.extend(where2)
-            params.extend(params2)
+            try:
+                joins2, where2, params2 = val.get_sql(opts)
+                joins.update(joins2)
+                where.extend(where2)
+                params.extend(params2)
+            except EmptyResultSet:
+                if not isinstance(self, QOr):
+                    raise EmptyResultSet
         if where:
             return joins, ['(%s)' % self.operator.join(where)], params
         return joins, [], params
@@ -628,8 +719,11 @@ class QNot(Q):
         self.q = q
 
     def get_sql(self, opts):
-        joins, where, params = self.q.get_sql(opts)
-        where2 = ['(NOT (%s))' % " AND ".join(where)]
+        try:
+            joins, where, params = self.q.get_sql(opts)
+            where2 = ['(NOT (%s))' % " AND ".join(where)]
+        except EmptyResultSet:
+            return SortedDict(), [], []
         return joins, where2, params
 
 def get_where_clause(lookup_type, table_prefix, field_name, value):
@@ -641,10 +735,14 @@ def get_where_clause(lookup_type, table_prefix, field_name, value):
     except KeyError:
         pass
     if lookup_type == 'in':
-        return '%s%s IN (%s)' % (table_prefix, field_name, ','.join(['%s' for v in value]))
-    elif lookup_type == 'range':
+        in_string = ','.join(['%s' for id in value])
+        if in_string:
+            return '%s%s IN (%s)' % (table_prefix, field_name, in_string)
+        else:
+            raise EmptyResultSet
+    elif lookup_type in ('range', 'year'):
         return '%s%s BETWEEN %%s AND %%s' % (table_prefix, field_name)
-    elif lookup_type in ('year', 'month', 'day'):
+    elif lookup_type in ('month', 'day'):
         return "%s = %%s" % backend.get_date_extract_sql(lookup_type, table_prefix + field_name)
     elif lookup_type == 'isnull':
         return "%s%s IS %sNULL" % (table_prefix, field_name, (not value and 'NOT ' or ''))
@@ -652,21 +750,33 @@ def get_where_clause(lookup_type, table_prefix, field_name, value):
         return backend.get_fulltext_search_sql(table_prefix + field_name)
     raise TypeError, "Got invalid lookup_type: %s" % repr(lookup_type)
 
-def get_cached_row(klass, row, index_start):
-    "Helper function that recursively returns an object with cache filled"
+def get_cached_row(klass, row, index_start, max_depth=0, cur_depth=0):
+    """Helper function that recursively returns an object with cache filled"""
+
+    # If we've got a max_depth set and we've exceeded that depth, bail now.
+    if max_depth and cur_depth > max_depth:
+        return None
+
     index_end = index_start + len(klass._meta.fields)
     obj = klass(*row[index_start:index_end])
     for f in klass._meta.fields:
         if f.rel and not f.null:
-            rel_obj, index_end = get_cached_row(f.rel.to, row, index_end)
-            setattr(obj, f.get_cache_name(), rel_obj)
+            cached_row = get_cached_row(f.rel.to, row, index_end, max_depth, cur_depth+1)
+            if cached_row:
+                rel_obj, index_end = cached_row
+                setattr(obj, f.get_cache_name(), rel_obj)
     return obj, index_end
 
-def fill_table_cache(opts, select, tables, where, old_prefix, cache_tables_seen):
+def fill_table_cache(opts, select, tables, where, old_prefix, cache_tables_seen, max_depth=0, cur_depth=0):
     """
     Helper function that recursively populates the select, tables and where (in
     place) for select_related queries.
     """
+
+    # If we've got a max_depth set and we've exceeded that depth, bail now.
+    if max_depth and cur_depth > max_depth:
+        return None
+
     qn = backend.quote_name
     for f in opts.fields:
         if f.rel and not f.null:
@@ -681,12 +791,12 @@ def fill_table_cache(opts, select, tables, where, old_prefix, cache_tables_seen)
             where.append('%s.%s = %s.%s' % \
                 (qn(old_prefix), qn(f.column), qn(db_table), qn(f.rel.get_related_field().column)))
             select.extend(['%s.%s' % (qn(db_table), qn(f2.column)) for f2 in f.rel.to._meta.fields])
-            fill_table_cache(f.rel.to._meta, select, tables, where, db_table, cache_tables_seen)
+            fill_table_cache(f.rel.to._meta, select, tables, where, db_table, cache_tables_seen, max_depth, cur_depth+1)
 
 def parse_lookup(kwarg_items, opts):
     # Helper function that handles converting API kwargs
     # (e.g. "name__exact": "tom") to SQL.
-    # Returns a tuple of (tables, joins, where, params).
+    # Returns a tuple of (joins, where, params).
 
     # 'joins' is a sorted dictionary describing the tables that must be joined
     # to complete the query. The dictionary is sorted because creation order
@@ -725,12 +835,14 @@ def parse_lookup(kwarg_items, opts):
 
         if len(path) < 1:
             raise TypeError, "Cannot parse keyword query %r" % kwarg
-        
+
         if value is None:
             # Interpret '__exact=None' as the sql '= NULL'; otherwise, reject
             # all uses of None as a query value.
             if lookup_type != 'exact':
                 raise ValueError, "Cannot use None as a query value"
+        elif callable(value):
+            value = value()
 
         joins2, where2, params2 = lookup_inner(path, lookup_type, value, opts, opts.db_table, None)
         joins.update(joins2)
@@ -755,6 +867,13 @@ def find_field(name, field_list, related_query):
         return None
     return matches[0]
 
+def field_choices(field_list, related_query):
+    if related_query:
+        choices = [f.field.related_query_name() for f in field_list]
+    else:
+        choices = [f.name for f in field_list]
+    return choices
+
 def lookup_inner(path, lookup_type, value, opts, table, column):
     qn = backend.quote_name
     joins, where, params = SortedDict(), [], []
@@ -827,13 +946,23 @@ def lookup_inner(path, lookup_type, value, opts, table, column):
                 new_opts = field.rel.to._meta
                 new_column = new_opts.pk.column
                 join_column = field.column
-
-            raise FieldFound
+                raise FieldFound
+            elif path:
+                # For regular fields, if there are still items on the path,
+                # an error has been made. We munge "name" so that the error
+                # properly identifies the cause of the problem.
+                name += LOOKUP_SEPARATOR + path[0]
+            else:
+                raise FieldFound
 
     except FieldFound: # Match found, loop has been shortcut.
         pass
     else: # No match found.
-        raise TypeError, "Cannot resolve keyword '%s' into field" % name
+        choices = field_choices(current_opts.many_to_many, False) + \
+            field_choices(current_opts.get_all_related_many_to_many_objects(), True) + \
+            field_choices(current_opts.get_all_related_objects(), True) + \
+            field_choices(current_opts.fields, False)
+        raise TypeError, "Cannot resolve keyword '%s' into field. Choices are: %s" % (name, ", ".join(choices))
 
     # Check whether an intermediate join is required between current_table
     # and new_table.
@@ -926,18 +1055,26 @@ def delete_objects(seen_objs):
 
         pk_list = [pk for pk,instance in seen_objs[cls]]
         for related in cls._meta.get_all_related_many_to_many_objects():
-            for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
-                cursor.execute("DELETE FROM %s WHERE %s IN (%s)" % \
-                    (qn(related.field.m2m_db_table()),
-                        qn(related.field.m2m_reverse_name()),
-                        ','.join(['%s' for pk in pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE]])),
-                    pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE])
+            if not isinstance(related.field, generic.GenericRelation):
+                for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
+                    cursor.execute("DELETE FROM %s WHERE %s IN (%s)" % \
+                        (qn(related.field.m2m_db_table()),
+                            qn(related.field.m2m_reverse_name()),
+                            ','.join(['%s' for pk in pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE]])),
+                        pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE])
         for f in cls._meta.many_to_many:
+            if isinstance(f, generic.GenericRelation):
+                from django.contrib.contenttypes.models import ContentType
+                query_extra = 'AND %s=%%s' % f.rel.to._meta.get_field(f.content_type_field_name).column
+                args_extra = [ContentType.objects.get_for_model(cls).id]
+            else:
+                query_extra = ''
+                args_extra = []
             for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
-                cursor.execute("DELETE FROM %s WHERE %s IN (%s)" % \
+                cursor.execute(("DELETE FROM %s WHERE %s IN (%s)" % \
                     (qn(f.m2m_db_table()), qn(f.m2m_column_name()),
-                    ','.join(['%s' for pk in pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE]])),
-                    pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE])
+                    ','.join(['%s' for pk in pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE]]))) + query_extra,
+                    pk_list[offset:offset+GET_ITERATOR_CHUNK_SIZE] + args_extra)
         for field in cls._meta.fields:
             if field.rel and field.null and field.rel.to in seen_objs:
                 for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
diff --git a/django/db/models/related.py b/django/db/models/related.py
index ac1ec50ca2..2c1dc5c516 100644
--- a/django/db/models/related.py
+++ b/django/db/models/related.py
@@ -1,7 +1,7 @@
 class BoundRelatedObject(object):
     def __init__(self, related_object, field_mapping, original):
         self.relation = related_object
-        self.field_mappings = field_mapping[related_object.opts.module_name]
+        self.field_mappings = field_mapping[related_object.name]
 
     def template_name(self):
         raise NotImplementedError
@@ -16,7 +16,7 @@ class RelatedObject(object):
         self.opts = model._meta
         self.field = field
         self.edit_inline = field.rel.edit_inline
-        self.name = self.opts.module_name
+        self.name = '%s:%s' % (self.opts.app_label, self.opts.module_name)
         self.var_name = self.opts.object_name.lower()
 
     def flatten_data(self, follow, obj=None):
@@ -68,7 +68,10 @@ class RelatedObject(object):
                 # object
                 return [attr]
         else:
-            return [None] * self.field.rel.num_in_admin
+            if self.field.rel.min_num_in_admin:
+                return [None] * max(self.field.rel.num_in_admin, self.field.rel.min_num_in_admin)
+            else:
+                return [None] * self.field.rel.num_in_admin
 
     def get_db_prep_lookup(self, lookup_type, value):
         # Defer to the actual field definition for db prep
@@ -101,12 +104,12 @@ class RelatedObject(object):
                 attr = getattr(manipulator.original_object, self.get_accessor_name())
                 count = attr.count()
                 count += self.field.rel.num_extra_on_change
-                if self.field.rel.min_num_in_admin:
-                    count = max(count, self.field.rel.min_num_in_admin)
-                if self.field.rel.max_num_in_admin:
-                    count = min(count, self.field.rel.max_num_in_admin)
             else:
                 count = self.field.rel.num_in_admin
+            if self.field.rel.min_num_in_admin:
+                count = max(count, self.field.rel.min_num_in_admin)
+            if self.field.rel.max_num_in_admin:
+                count = min(count, self.field.rel.max_num_in_admin)
         else:
             count = 1
 
diff --git a/django/db/transaction.py b/django/db/transaction.py
index 4a0658e1c3..bb90713525 100644
--- a/django/db/transaction.py
+++ b/django/db/transaction.py
@@ -46,12 +46,12 @@ def enter_transaction_management():
     when no current block is running).
     """
     thread_ident = thread.get_ident()
-    if state.has_key(thread_ident) and state[thread_ident]:
+    if thread_ident in state and state[thread_ident]:
         state[thread_ident].append(state[thread_ident][-1])
     else:
         state[thread_ident] = []
         state[thread_ident].append(settings.TRANSACTIONS_MANAGED)
-    if not dirty.has_key(thread_ident):
+    if thread_ident not in dirty:
         dirty[thread_ident] = False
 
 def leave_transaction_management():
@@ -61,7 +61,7 @@ def leave_transaction_management():
     those from outside. (Commits are on connection level.)
     """
     thread_ident = thread.get_ident()
-    if state.has_key(thread_ident) and state[thread_ident]:
+    if thread_ident in state and state[thread_ident]:
         del state[thread_ident][-1]
     else:
         raise TransactionManagementError("This code isn't under transaction management")
@@ -84,7 +84,7 @@ def set_dirty():
     changes waiting for commit.
     """
     thread_ident = thread.get_ident()
-    if dirty.has_key(thread_ident):
+    if thread_ident in dirty:
         dirty[thread_ident] = True
     else:
         raise TransactionManagementError("This code isn't under transaction management")
@@ -96,7 +96,7 @@ def set_clean():
     should happen.
     """
     thread_ident = thread.get_ident()
-    if dirty.has_key(thread_ident):
+    if thread_ident in dirty:
         dirty[thread_ident] = False
     else:
         raise TransactionManagementError("This code isn't under transaction management")
@@ -106,7 +106,7 @@ def is_managed():
     Checks whether the transaction manager is in manual or in auto state.
     """
     thread_ident = thread.get_ident()
-    if state.has_key(thread_ident):
+    if thread_ident in state:
         if state[thread_ident]:
             return state[thread_ident][-1]
     return settings.TRANSACTIONS_MANAGED