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"""
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]
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(object):
"""MySQL Database Connection Object"""
errorhandler = defaulterrorhandler
from MySQLdb.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
decoders
list, SQL decoder stack
encoders
list, SQL encoder stack
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
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 default_decoders, default_encoders
from MySQLdb.converters import simple_type_encoders as conversions
from MySQLdb.cursors import Cursor
import _mysql
kwargs2 = kwargs.copy()
self.cursorclass = Cursor
charset = kwargs2.pop('charset', '')
if 'decoder_stack' not in kwargs2:
kwargs2['decoder_stack'] = default_decoders;
self.encoders = kwargs2.pop('encoders', default_encoders)
self.decoders = kwargs2.pop('decoders', default_decoders)
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
sql_mode = kwargs2.pop('sql_mode', None)
self._db = _mysql.connection(*args, **kwargs2)
self._server_version = tuple(
[ int(n) for n in self._db.get_server_info().split('.')[:2] ])
if charset:
self._db.set_character_set(charset)
if sql_mode:
self.set_sql_mode(sql_mode)
self._transactional = bool(self._db.server_capabilities & CLIENT.TRANSACTIONS)
if self._transactional:
# PEP-249 requires autocommit to be initially off
self.autocommit(False)
self.messages = []
self._active_cursor = None
def autocommit(self, do_autocommit):
self._autocommit = do_autocommit
return self._db.autocommit(do_autocommit)
def ping(self, reconnect=False):
if reconnect and not self._autocommit:
raise ProgrammingError("autocommit must be enabled before enabling auto-reconnect; consider the consequences")
return self._db.ping(reconnect)
def commit(self):
return self._db.commit()
def rollback(self):
return self._db.rollback()
def close(self):
return self._db.close()
def escape_string(self, s):
return self._db.escape_string(s)
def string_literal(self, s):
return self._db.string_literal(s)
def cursor(self, encoders=None, decoders=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.
"""
if self._active_cursor:
self._active_cursor._flush()
if not encoders:
encoders = self.encoders[:]
if not decoders:
decoders = self.decoders[:]
self._active_cursor = self.cursorclass(self, encoders, decoders)
return self._active_cursor
def __enter__(self):
return self.cursor()
def __exit__(self, exc, value, traceback):
if exc:
self.rollback()
else:
self.commit()
def literal(self, obj):
"""
Given an object obj, returns an SQL literal as a string.
Non-standard.
"""
for encoder in self.encoders:
f = encoder(obj)
if f:
return f(self, obj)
raise self.NotSupportedError("could not encode as SQL", obj)
def _warning_count(self):
"""Return the number of warnings generated from the last query."""
if hasattr(self._db, "warning_count"):
return self._db.warning_count()
else:
info = self._db.info()
if info:
return int(info.split()[-1])
else:
return 0
def character_set_name(self):
return self._db.character_set_name()
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:
self._db.set_character_set(charset)
except AttributeError:
if self._server_version < (4, 1):
raise self.NotSupportedError("server is too old to set charset")
self._db.query('SET NAMES %s' % charset)
self._db.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._db.query("SET SESSION sql_mode='%s'" % sql_mode)
self._db.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._db.query("SHOW WARNINGS")
result = self._db.store_result()
warnings = result.fetch_row(0)
return warnings