Viewing: connections.py
"""
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.
"""
import re
import sys
from MySQLdb import cursors, _mysql
from MySQLdb.compat import unicode, PY2
from MySQLdb._exceptions import (
Warning, Error, InterfaceError, DataError,
DatabaseError, OperationalError, IntegrityError, InternalError,
NotSupportedError, ProgrammingError,
)
# Mapping from MySQL charset name to Python codec name
_charset_to_encoding = {
"utf8mb4": "utf8",
"utf8mb3": "utf8",
"latin1": "cp1252",
"koi8r": "koi8_r",
"koi8u": "koi8_u",
}
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
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.
:param str host: host to connect
:param str user: user to connect as
:param str password: password to use
:param str passwd: alias of password, for backward compatibility
:param str database: database to use
:param str db: alias of database, for backward compatibility
:param int port: TCP/IP port to connect to
:param str unix_socket: location of unix_socket to use
:param dict conv: conversion dictionary, see MySQLdb.converters
:param int connect_timeout:
number of seconds to wait before the connection attempt fails.
:param bool compress: if set, compression is enabled
:param str named_pipe: if set, a named pipe is used to connect (Windows only)
:param str init_command:
command which is run once the connection is created
:param str read_default_file:
file from which default client values are read
:param str read_default_group:
configuration group to use from the default file
:param type cursorclass:
class object, used to create cursors (keyword only)
:param bool 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 bytes. 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
so that you can always get python `str` object by default.
:param str charset:
If supplied, the connection character set will be changed
to this character set.
On Python 2, this option changes default value of `use_unicode`
option from False to True.
:param str auth_plugin:
If supplied, the connection default authentication plugin will be
changed to this value. Example values:
`mysql_native_password` or `caching_sha2_password`
:param str sql_mode:
If supplied, the session SQL mode will be changed to this
setting.
For more details and legal values, see the MySQL documentation.
:param int client_flag:
flags to use or 0 (see MySQL docs or constants/CLIENTS.py)
:param dict 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.
:param bool local_infile:
enables LOAD LOCAL INFILE; zero disables
:param bool autocommit:
If False (default), autocommit is disabled.
If True, autocommit is enabled.
If None, autocommit isn't set and server default is used.
:param bool binary_prefix:
If set, the '_binary' prefix will be used for raw byte query
arguments (e.g. Binary). This is disabled by default.
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, _bytes_or_str
from weakref import proxy
kwargs2 = kwargs.copy()
if 'database' in kwargs2:
kwargs2['db'] = kwargs2.pop('database')
if 'password' in kwargs2:
kwargs2['passwd'] = kwargs2.pop('password')
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.get('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', '')
self._binary_prefix = kwargs2.pop('binary_prefix', False)
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)
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 ])
# XXX THIS IS GARBAGE: While this is just a garbage and undocumented,
# Django 1.11 depends on it. And they don't fix it because
# they are in security-only fix mode.
# So keep this garbage for now. This will be removed in 1.5.
# See PyMySQL/mysqlclient-python#306
self.encoders[bytes] = bytes
self._server_version = tuple([ numeric_part(n) for n in self.get_server_info().split('.')[:2] ])
self.encoding = 'ascii' # overridden in set_character_set()
db = proxy(self)
def unicode_literal(u, dummy=None):
return db.string_literal(u.encode(db.encoding))
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:
for t in (FIELD_TYPE.STRING, FIELD_TYPE.VAR_STRING, FIELD_TYPE.VARCHAR, FIELD_TYPE.TINY_BLOB,
FIELD_TYPE.MEDIUM_BLOB, FIELD_TYPE.LONG_BLOB, FIELD_TYPE.BLOB):
self.converter[t] = _bytes_or_str
# Unlike other string/blob types, JSON is always text.
# MySQL may return JSON with charset==binary.
self.converter[FIELD_TYPE.JSON] = unicode
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):
# Since _mysql releases GIL while querying, we need immutable buffer.
if isinstance(query, bytearray):
query = bytes(query)
_mysql.connection.query(self, query)
def _bytes_literal(self, bs):
assert isinstance(bs, (bytes, bytearray))
x = self.string_literal(bs) # x is escaped and quoted bytes
if self._binary_prefix:
return b'_binary' + x
return x
def _tuple_literal(self, t):
return b"(%s)" % (b','.join(map(self.literal, t)))
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.
"""
if isinstance(o, unicode):
s = self.string_literal(o.encode(self.encoding))
elif isinstance(o, bytearray):
s = self._bytes_literal(o)
elif isinstance(o, bytes):
if PY2:
s = self.string_literal(o)
else:
s = self._bytes_literal(o)
elif isinstance(o, (tuple, list)):
s = self._tuple_literal(o)
else:
s = self.escape(o, self.encoders)
if isinstance(s, unicode):
s = s.encode(self.encoding)
assert isinstance(s, bytes)
return s
def begin(self):
"""Explicitly begin a connection.
This method is not used when autocommit=False (default).
"""
self.query(b"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."""
py_charset = _charset_to_encoding.get(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.encoding = 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
# vim: colorcolumn=100
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