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Editing: 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 from MySQLdb.compat import unicode, PY2 from _mysql_exceptions import ( Warning, Error, InterfaceError, DataError, DatabaseError, OperationalError, IntegrityError, InternalError, NotSupportedError, ProgrammingError, ) import _mysql if not PY2: if sys.version_info[:2] < (3, 6): # See http://bugs.python.org/issue24870 _surrogateescape_table = [chr(i) if i < 0x80 else chr(i + 0xdc00) for i in range(256)] def _fast_surrogateescape(s): return s.decode('latin1').translate(_surrogateescape_table) else: def _fast_surrogateescape(s): return s.decode('ascii', 'surrogateescape') 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. :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 str 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. :param str charset: If supplied, the connection character set will be changed to this character set (MySQL-4.1 and newer). This implies use_unicode=True. :param str 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. :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 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.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', '') 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) 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 (via bytes_literal) 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.string_literal(u.encode(unicode_literal.charset)) else: # unicode_literal() is called for arbitrary object. def unicode_literal(u, dummy=None): return db.string_literal(str(u).encode(unicode_literal.charset)) return unicode_literal def _get_bytes_literal(): def bytes_literal(obj, dummy=None): return b'_binary' + db.string_literal(obj) return bytes_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() bytes_literal = _get_bytes_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)) if binary_prefix: self.encoders[bytes] = string_literal if PY2 else bytes_literal self.encoders[bytearray] = bytes_literal else: 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): # Since _mysql releases GIL while querying, we need immutable buffer. if isinstance(query, bytearray): query = bytes(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): from warnings import warn warn("context interface will be changed. Use explicit conn.commit() or conn.rollback().", DeprecationWarning, 2) 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(~3.4) 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, bytearray)): return _fast_surrogateescape(s) 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 1.4", 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 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 errorhandler = defaulterrorhandler # vim: colorcolumn=100
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