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"""
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.
"""
from MySQLdb import cursors
from MySQLdb.compat import unicode, PY2
from _mysql_exceptions import Warning, Error, InterfaceError, DataError, \
DatabaseError, OperationalError, IntegrityError, InternalError, \
NotSupportedError, ProgrammingError
import _mysql
import re
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
if isinstance(errorvalue, BaseException):
raise errorvalue
if errorclass is not None:
raise errorclass(errorvalue)
else:
raise Exception(errorvalue)
re_numeric_part = re.compile(r"^(\d+)")
def numeric_part(s):
"""Returns the leading numeric part of a string.
>>> numeric_part("20-alpha")
20
>>> numeric_part("foo")
>>> numeric_part("16b")
16
"""
m = re_numeric_part.match(s)
if m:
return int(m.group(1))
return None
class Connection(_mysql.connection):
"""MySQL Database Connection Object"""
default_cursor = cursors.Cursor
waiter = None
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.
Default to False on Python 2 and True on Python 3.
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
autocommit
If False (default), autocommit is disabled.
If True, autocommit is enabled.
If None, autocommit isn't set and server default is used.
waiter
Callable accepts fd as an argument. It is called after sending
query and before reading response.
This is useful when using with greenlet and async io.
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 'conv' in kwargs:
conv = kwargs['conv']
else:
conv = conversions
conv2 = {}
for k, v in conv.items():
if isinstance(k, int) and isinstance(v, list):
conv2[k] = v[:]
else:
conv2[k] = v
kwargs2['conv'] = conv2
cursorclass = kwargs2.pop('cursorclass', self.default_cursor)
charset = kwargs2.pop('charset', '')
if charset or not PY2:
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([ numeric_part(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
# PEP-249 requires autocommit to be initially off
autocommit = kwargs2.pop('autocommit', False)
self.waiter = kwargs2.pop('waiter', None)
super(Connection, self).__init__(*args, **kwargs2)
self.cursorclass = cursorclass
self.encoders = dict([ (k, v) for k, v in conv.items()
if type(k) is not int ])
self._server_version = tuple([ numeric_part(n) for n in self.get_server_info().split('.')[:2] ])
db = proxy(self)
def _get_string_literal():
# Note: string_literal() is called for bytes object on Python 3.
def string_literal(obj, dummy=None):
return db.string_literal(obj)
return string_literal
def _get_unicode_literal():
if PY2:
# unicode_literal is called for only unicode object.
def unicode_literal(u, dummy=None):
return db.literal(u.encode(unicode_literal.charset))
else:
# unicode_literal() is called for arbitrary object.
def unicode_literal(u, dummy=None):
return db.literal(str(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[bytes] = string_literal
self.encoders[unicode] = unicode_literal
self._transactional = self.server_capabilities & CLIENT.TRANSACTIONS
if self._transactional:
if autocommit is not None:
self.autocommit(autocommit)
self.messages = []
def autocommit(self, on):
on = bool(on)
if self.get_autocommit() != on:
_mysql.connection.autocommit(self, on)
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 query(self, query):
if self.waiter is not None:
self.send_query(query)
self.waiter(self.fileno())
self.read_query_result()
else:
_mysql.connection.query(self, query)
def __enter__(self):
if self.get_autocommit():
self.query("BEGIN")
return self.cursor()
def __exit__(self, exc, value, tb):
if exc:
self.rollback()
else:
self.commit()
def literal(self, o):
"""
If o is a single object, returns an SQL literal as a string.
If o 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.
"""
s = self.escape(o, self.encoders)
# Python 3 doesn't support % operation for bytes object.
# We should decode it before using %.
# Decoding with ascii and surrogateescape allows convert arbitrary
# bytes to unicode and back again.
# See http://python.org/dev/peps/pep-0383/
if not PY2 and isinstance(s, bytes):
return s.decode('ascii', 'surrogateescape')
return s
def begin(self):
"""Explicitly begin a connection. Non-standard.
DEPRECATED: Will be removed in 1.3.
Use an SQL BEGIN statement instead."""
from warnings import warn
warn("begin() is non-standard and will be removed in 1.3",
DeprecationWarning, 2)
self.query("BEGIN")
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."""
if charset == "utf8mb4":
py_charset = "utf8"
else:
py_charset = charset
if self.character_set_name() != charset:
try:
super(Connection, self).set_character_set(charset)
except AttributeError:
if self._server_version < (4, 1):
raise NotSupportedError("server is too old to set charset")
self.query('SET NAMES %s' % charset)
self.store_result()
self.string_decoder.charset = py_charset
self.unicode_literal.charset = py_charset
def set_sql_mode(self, sql_mode):
"""Set the connection sql_mode. See MySQL documentation for
legal values."""
if self._server_version < (4, 1):
raise 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."""
if self._server_version < (4,1): return ()
self.query("SHOW WARNINGS")
r = self.store_result()
warnings = r.fetch_row(0)
return warnings
Warning = Warning
Error = Error
InterfaceError = InterfaceError
DatabaseError = DatabaseError
DataError = DataError
OperationalError = OperationalError
IntegrityError = IntegrityError
InternalError = InternalError
ProgrammingError = ProgrammingError
NotSupportedError = NotSupportedError
errorhandler = defaulterrorhandler
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