"""
MySQLdb Connections
-------------------
This module implements connections for MySQLdb. Presently there is
only one class: Connection. Others are unlikely. However, you might
want to make your own subclasses. In most cases, you will probably
override Connection.default_cursor with a non-standard Cursor class.
"""
__revision__ = "$Revision$"[11:-2]
__author__ = "$Author$"[9:-2]
from MySQLdb.cursors import Cursor
import _mysql
def defaulterrorhandler(connection, cursor, errorclass, errorvalue):
"""
If cursor is not None, (errorclass, errorvalue) is appended to
cursor.messages; otherwise it is appended to connection.messages. Then
errorclass is raised with errorvalue as the value.
You can override this with your own error handler by assigning it to the
instance.
"""
error = errorclass, errorvalue
if cursor:
cursor.messages.append(error)
else:
connection.messages.append(error)
del cursor
del connection
raise errorclass, errorvalue
class Connection(_mysql.connection):
"""MySQL Database Connection Object"""
default_cursor = Cursor
errorhandler = defaulterrorhandler
from _mysql_exceptions import Warning, Error, InterfaceError, DataError, \
DatabaseError, OperationalError, IntegrityError, InternalError, \
NotSupportedError, ProgrammingError
def __init__(self, *args, **kwargs):
"""
Create a connection to the database. It is strongly recommended that
you only use keyword parameters. Consult the MySQL C API documentation
for more information.
host
string, host to connect
user
string, user to connect as
passwd
string, password to use
db
string, database to use
port
integer, TCP/IP port to connect to
unix_socket
string, location of unix_socket to use
conv
conversion dictionary, see MySQLdb.converters
connect_timeout
number of seconds to wait before the connection attempt
fails.
compress
if set, compression is enabled
named_pipe
if set, a named pipe is used to connect (Windows only)
init_command
command which is run once the connection is created
read_default_file
file from which default client values are read
read_default_group
configuration group to use from the default file
cursorclass
class object, used to create cursors (keyword only)
use_unicode
If True, text-like columns are returned as unicode objects
using the connection's character set. Otherwise, text-like
columns are returned as strings. columns are returned as
normal strings. Unicode objects will always be encoded to
the connection's character set regardless of this setting.
charset
If supplied, the connection character set will be changed
to this character set (MySQL-4.1 and newer). This implies
use_unicode=True.
sql_mode
If supplied, the session SQL mode will be changed to this
setting (MySQL-4.1 and newer). For more details and legal
values, see the MySQL documentation.
client_flag
integer, flags to use or 0
(see MySQL docs or constants/CLIENTS.py)
ssl
dictionary or mapping, contains SSL connection parameters;
see the MySQL documentation for more details
(mysql_ssl_set()). If this is set, and the client does not
support SSL, NotSupportedError will be raised.
local_infile
integer, non-zero enables LOAD LOCAL INFILE; zero disables
There are a number of undocumented, non-standard methods. See the
documentation for the MySQL C API for some hints on what they do.
"""
from MySQLdb.constants import CLIENT, FIELD_TYPE
from MySQLdb.converters import conversions
from weakref import proxy
kwargs2 = kwargs.copy()
if kwargs.has_key('conv'):
conv = kwargs['conv']
else:
conv = conversions
conv2 = {}
for k, v in conv.items():
if isinstance(k, int):
if isinstance(v, list):
conv2[k] = v[:]
else:
conv2[k] = v
kwargs2['conv'] = conv2
self.cursorclass = kwargs2.pop('cursorclass', self.default_cursor)
charset = kwargs2.pop('charset', '')
if charset:
use_unicode = True
else:
use_unicode = False
use_unicode = kwargs2.pop('use_unicode', use_unicode)
sql_mode = kwargs2.pop('sql_mode', '')
client_flag = kwargs.get('client_flag', 0)
client_version = tuple(
[ int(n) for n in _mysql.get_client_info().split('.')[:2] ])
if client_version >= (4, 1):
client_flag |= CLIENT.MULTI_STATEMENTS
if client_version >= (5, 0):
client_flag |= CLIENT.MULTI_RESULTS
kwargs2['client_flag'] = client_flag
super(Connection, self).__init__(*args, **kwargs2)
self.encoders = dict(
[ (k, v) for k, v in conv.items()
if type(k) is not int ])
self._server_version = tuple(
[ int(n) for n in self.get_server_info().split('.')[:2] ])
db = proxy(self)
def _get_string_literal():
def string_literal(obj, dummy=None):
return db.string_literal(obj)
return string_literal
def _get_unicode_literal():
def unicode_literal(u, dummy=None):
return db.literal(u.encode(unicode_literal.charset))
return unicode_literal
def _get_string_decoder():
def string_decoder(s):
return s.decode(string_decoder.charset)
return string_decoder
string_literal = _get_string_literal()
self.unicode_literal = unicode_literal = _get_unicode_literal()
self.string_decoder = string_decoder = _get_string_decoder()
if not charset:
charset = self.character_set_name()
self.set_character_set(charset)
if sql_mode:
self.set_sql_mode(sql_mode)
if use_unicode:
self.converter[FIELD_TYPE.STRING].append((None, string_decoder))
self.converter[FIELD_TYPE.VAR_STRING].append((None, string_decoder))
self.converter[FIELD_TYPE.VARCHAR].append((None, string_decoder))
self.converter[FIELD_TYPE.BLOB].append((None, string_decoder))
self.encoders[str] = string_literal
self.encoders[unicode] = unicode_literal
self._transactional = self.server_capabilities & CLIENT.TRANSACTIONS
if self._transactional:
# PEP-249 requires autocommit to be initially off
self.autocommit(False)
self.messages = []
def cursor(self, cursorclass=None):
"""
Create a cursor on which queries may be performed. The optional
cursorclass parameter is used to create the Cursor. By default,
self.cursorclass=cursors.Cursor is used.
"""
return (cursorclass or self.cursorclass)(self)
def __enter__(self):
return self.cursor()
def __exit__(self, exc, value, traceback):
if exc:
self.rollback()
else:
self.commit()
def literal(self, obj):
"""
If obj is a single object, returns an SQL literal as a string. If
obj is a non-string sequence, the items of the sequence are converted
and returned as a sequence.
Non-standard. For internal use; do not use this in your applications.
"""
return self.escape(obj, self.encoders)
if not hasattr(_mysql.connection, 'warning_count'):
def warning_count(self):
"""Return the number of warnings generated from the last query.
This is derived from the info() method."""
info = self.info()
if info:
return int(info.split()[-1])
else:
return 0
def set_character_set(self, charset):
"""Set the connection character set to charset. The character set can
only be changed in MySQL-4.1 and newer. If you try to change the
character set from the current value in an older version,
NotSupportedError will be raised.
Non-standard. It is better to set the character set when creating the
connection using the charset parameter."""
if self.character_set_name() != charset:
try:
super(Connection, self).set_character_set(charset)
except AttributeError:
if self._server_version < (4, 1):
raise self.NotSupportedError, "server is too old to set charset"
self.query('SET NAMES %s' % charset)
self.store_result()
self.string_decoder.charset = charset
self.unicode_literal.charset = charset
def set_sql_mode(self, sql_mode):
"""Set the connection sql_mode. See MySQL documentation for legal
values.
Non-standard. It is better to set this when creating the connection
using the sql_mode parameter."""
if self._server_version < (4, 1):
raise self.NotSupportedError, "server is too old to set sql_mode"
self.query("SET SESSION sql_mode='%s'" % sql_mode)
self.store_result()
def show_warnings(self):
"""Return detailed information about warnings as a sequence of tuples
of (Level, Code, Message). This is only supported in MySQL-4.1 and up.
If your server is an earlier version, an empty sequence is returned.
Non-standard. This is invoked automatically after executing a query,
so you should not usually call it yourself."""
if self._server_version < (4, 1): return ()
self.query("SHOW WARNINGS")
result = self.store_result()
warnings = result.fetch_row(0)
return warnings
