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

23 files changed, 846 insertions, 75 deletions

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 #
 ##################################################################################