查源码分析 游标 写 需要 cursors 一切不看源码的代码引入都是定时炸弹的启动
https://github.com/PyMySQL/PyMySQL/blob/master/pymysql/__init__.py
建立连接
def Connect(*args, **kwargs): """ Connect to the database; see connections.Connection.__init__() for more information. """ from .connections import Connection return Connection(*args, **kwargs)
https://github.com/PyMySQL/PyMySQL/blob/master/pymysql/connections.py
class Connection(object): """ Representation of a socket with a mysql server. The proper way to get an instance of this class is to call connect(). Establish a connection to the MySQL database. Accepts several arguments: :param host: Host where the database server is located :param user: Username to log in as :param password: Password to use. :param database: Database to use, None to not use a particular one. :param port: MySQL port to use, default is usually OK. (default: 3306) :param bind_address: When the client has multiple network interfaces, specify the interface from which to connect to the host. Argument can be a hostname or an IP address. :param unix_socket: Optionally, you can use a unix socket rather than TCP/IP. :param read_timeout: The timeout for reading from the connection in seconds (default: None - no timeout) :param write_timeout: The timeout for writing to the connection in seconds (default: None - no timeout) :param charset: Charset you want to use. :param sql_mode: Default SQL_MODE to use. :param read_default_file: Specifies my.cnf file to read these parameters from under the [client] section. :param conv: Conversion dictionary to use instead of the default one. This is used to provide custom marshalling and unmarshaling of types. See converters. :param use_unicode: Whether or not to default to unicode strings. This option defaults to true for Py3k. :param client_flag: Custom flags to send to MySQL. Find potential values in constants.CLIENT. :param cursorclass: Custom cursor class to use. :param init_command: Initial SQL statement to run when connection is established. :param connect_timeout: Timeout before throwing an exception when connecting. (default: 10, min: 1, max: 31536000) :param ssl: A dict of arguments similar to mysql_ssl_set()'s parameters. For now the capath and cipher arguments are not supported. :param read_default_group: Group to read from in the configuration file. :param compress: Not supported :param named_pipe: Not supported :param autocommit: Autocommit mode. None means use server default. (default: False) :param local_infile: Boolean to enable the use of LOAD DATA LOCAL command. (default: False) :param max_allowed_packet: Max size of packet sent to server in bytes. (default: 16MB) Only used to limit size of "LOAD LOCAL INFILE" data packet smaller than default (16KB). :param defer_connect: Don't explicitly connect on contruction - wait for connect call. (default: False) :param auth_plugin_map: A dict of plugin names to a class that processes that plugin. The class will take the Connection object as the argument to the constructor. The class needs an authenticate method taking an authentication packet as an argument. For the dialog plugin, a prompt(echo, prompt) method can be used (if no authenticate method) for returning a string from the user. (experimental) :param db: Alias for database. (for compatibility to MySQLdb) :param passwd: Alias for password. (for compatibility to MySQLdb) :param binary_prefix: Add _binary prefix on bytes and bytearray. (default: False) See `Connection <https://www.python.org/dev/peps/pep-0249/#connection-objects>`_ in the specification. """ _sock = None _auth_plugin_name = '' _closed = False def __init__(self, host=None, user=None, password="", database=None, port=0, unix_socket=None, charset='', sql_mode=None, read_default_file=None, conv=None, use_unicode=None, client_flag=0, cursorclass=Cursor, init_command=None, connect_timeout=10, ssl=None, read_default_group=None, compress=None, named_pipe=None, no_delay=None, autocommit=False, db=None, passwd=None, local_infile=False, max_allowed_packet=16*1024*1024, defer_connect=False, auth_plugin_map={}, read_timeout=None, write_timeout=None, bind_address=None, binary_prefix=False): if no_delay is not None: warnings.warn("no_delay option is deprecated", DeprecationWarning) if use_unicode is None and sys.version_info[0] > 2: use_unicode = True if db is not None and database is None: database = db if passwd is not None and not password: password = passwd if compress or named_pipe: raise NotImplementedError("compress and named_pipe arguments are not supported") self._local_infile = bool(local_infile) if self._local_infile: client_flag |= CLIENT.LOCAL_FILES if read_default_group and not read_default_file: if sys.platform.startswith("win"): read_default_file = "c:\\my.ini" else: read_default_file = "/etc/my.cnf" if read_default_file: if not read_default_group: read_default_group = "client" cfg = Parser() cfg.read(os.path.expanduser(read_default_file)) def _config(key, arg): if arg: return arg try: return cfg.get(read_default_group, key) except Exception: return arg user = _config("user", user) password = _config("password", password) host = _config("host", host) database = _config("database", database) unix_socket = _config("socket", unix_socket) port = int(_config("port", port)) bind_address = _config("bind-address", bind_address) charset = _config("default-character-set", charset) if not ssl: ssl = {} if isinstance(ssl, dict): for key in ["ca", "capath", "cert", "key", "cipher"]: value = _config("ssl-" + key, ssl.get(key)) if value: ssl[key] = value self.ssl = False if ssl: if not SSL_ENABLED: raise NotImplementedError("ssl module not found") self.ssl = True client_flag |= CLIENT.SSL self.ctx = self._create_ssl_ctx(ssl) self.host = host or "localhost" self.port = port or 3306 self.user = user or DEFAULT_USER self.password = password or "" self.db = database self.unix_socket = unix_socket self.bind_address = bind_address if not (0 < connect_timeout <= 31536000): raise ValueError("connect_timeout should be >0 and <=31536000") self.connect_timeout = connect_timeout or None if read_timeout is not None and read_timeout <= 0: raise ValueError("read_timeout should be >= 0") self._read_timeout = read_timeout if write_timeout is not None and write_timeout <= 0: raise ValueError("write_timeout should be >= 0") self._write_timeout = write_timeout if charset: self.charset = charset self.use_unicode = True else: self.charset = DEFAULT_CHARSET self.use_unicode = False if use_unicode is not None: self.use_unicode = use_unicode self.encoding = charset_by_name(self.charset).encoding client_flag |= CLIENT.CAPABILITIES if self.db: client_flag |= CLIENT.CONNECT_WITH_DB self.client_flag = client_flag self.cursorclass = cursorclass self._result = None self._affected_rows = 0 self.host_info = "Not connected" #: specified autocommit mode. None means use server default. self.autocommit_mode = autocommit if conv is None: conv = converters.conversions # Need for MySQLdb compatibility. self.encoders = dict([(k, v) for (k, v) in conv.items() if type(k) is not int]) self.decoders = dict([(k, v) for (k, v) in conv.items() if type(k) is int]) self.sql_mode = sql_mode self.init_command = init_command self.max_allowed_packet = max_allowed_packet self._auth_plugin_map = auth_plugin_map self._binary_prefix = binary_prefix if defer_connect: self._sock = None else: self.connect() def _create_ssl_ctx(self, sslp): if isinstance(sslp, ssl.SSLContext): return sslp ca = sslp.get('ca') capath = sslp.get('capath') hasnoca = ca is None and capath is None ctx = ssl.create_default_context(cafile=ca, capath=capath) ctx.check_hostname = not hasnoca and sslp.get('check_hostname', True) ctx.verify_mode = ssl.CERT_NONE if hasnoca else ssl.CERT_REQUIRED if 'cert' in sslp: ctx.load_cert_chain(sslp['cert'], keyfile=sslp.get('key')) if 'cipher' in sslp: ctx.set_ciphers(sslp['cipher']) ctx.options |= ssl.OP_NO_SSLv2 ctx.options |= ssl.OP_NO_SSLv3 return ctx def close(self): """ Send the quit message and close the socket. See `Connection.close() <https://www.python.org/dev/peps/pep-0249/#Connection.close>`_ in the specification. :raise Error: If the connection is already closed. """ if self._closed: raise err.Error("Already closed") self._closed = True if self._sock is None: return send_data = struct.pack('<iB', 1, COMMAND.COM_QUIT) try: self._write_bytes(send_data) except Exception: pass finally: self._force_close() @property def open(self): """Return True if the connection is open""" return self._sock is not None def _force_close(self): """Close connection without QUIT message""" if self._sock: try: self._sock.close() except: pass self._sock = None self._rfile = None __del__ = _force_close def autocommit(self, value): self.autocommit_mode = bool(value) current = self.get_autocommit() if value != current: self._send_autocommit_mode() def get_autocommit(self): return bool(self.server_status & SERVER_STATUS.SERVER_STATUS_AUTOCOMMIT) def _read_ok_packet(self): pkt = self._read_packet() if not pkt.is_ok_packet(): raise err.OperationalError(2014, "Command Out of Sync") ok = OKPacketWrapper(pkt) self.server_status = ok.server_status return ok def _send_autocommit_mode(self): """Set whether or not to commit after every execute()""" self._execute_command(COMMAND.COM_QUERY, "SET AUTOCOMMIT = %s" % self.escape(self.autocommit_mode)) self._read_ok_packet() def begin(self): """Begin transaction.""" self._execute_command(COMMAND.COM_QUERY, "BEGIN") self._read_ok_packet() def commit(self): """ Commit changes to stable storage. See `Connection.commit() <https://www.python.org/dev/peps/pep-0249/#commit>`_ in the specification. """ self._execute_command(COMMAND.COM_QUERY, "COMMIT") self._read_ok_packet() def rollback(self): """ Roll back the current transaction. See `Connection.rollback() <https://www.python.org/dev/peps/pep-0249/#rollback>`_ in the specification. """ self._execute_command(COMMAND.COM_QUERY, "ROLLBACK") self._read_ok_packet() def show_warnings(self): """Send the "SHOW WARNINGS" SQL command.""" self._execute_command(COMMAND.COM_QUERY, "SHOW WARNINGS") result = MySQLResult(self) result.read() return result.rows def select_db(self, db): """ Set current db. :param db: The name of the db. """ self._execute_command(COMMAND.COM_INIT_DB, db) self._read_ok_packet() def escape(self, obj, mapping=None): """Escape whatever value you pass to it. Non-standard, for internal use; do not use this in your applications. """ if isinstance(obj, str_type): return "'" + self.escape_string(obj) + "'" if isinstance(obj, (bytes, bytearray)): ret = self._quote_bytes(obj) if self._binary_prefix: ret = "_binary" + ret return ret return converters.escape_item(obj, self.charset, mapping=mapping) def literal(self, obj): """Alias for escape() Non-standard, for internal use; do not use this in your applications. """ return self.escape(obj, self.encoders) def escape_string(self, s): if (self.server_status & SERVER_STATUS.SERVER_STATUS_NO_BACKSLASH_ESCAPES): return s.replace("'", "''") return converters.escape_string(s) def _quote_bytes(self, s): if (self.server_status & SERVER_STATUS.SERVER_STATUS_NO_BACKSLASH_ESCAPES): return "'%s'" % (_fast_surrogateescape(s.replace(b"'", b"''")),) return converters.escape_bytes(s) def cursor(self, cursor=None): """ Create a new cursor to execute queries with. :param cursor: The type of cursor to create; one of :py:class:`Cursor`, :py:class:`SSCursor`, :py:class:`DictCursor`, or :py:class:`SSDictCursor`. None means use Cursor. """ if cursor: return cursor(self) return self.cursorclass(self) def __enter__(self): """Context manager that returns a Cursor""" return self.cursor() def __exit__(self, exc, value, traceback): """On successful exit, commit. On exception, rollback""" if exc: self.rollback() else: self.commit() # The following methods are INTERNAL USE ONLY (called from Cursor) def query(self, sql, unbuffered=False): # if DEBUG: # print("DEBUG: sending query:", sql) if isinstance(sql, text_type) and not (JYTHON or IRONPYTHON): if PY2: sql = sql.encode(self.encoding) else: sql = sql.encode(self.encoding, 'surrogateescape') self._execute_command(COMMAND.COM_QUERY, sql) self._affected_rows = self._read_query_result(unbuffered=unbuffered) return self._affected_rows def next_result(self, unbuffered=False): self._affected_rows = self._read_query_result(unbuffered=unbuffered) return self._affected_rows def affected_rows(self): return self._affected_rows def kill(self, thread_id): arg = struct.pack('<I', thread_id) self._execute_command(COMMAND.COM_PROCESS_KILL, arg) return self._read_ok_packet() def ping(self, reconnect=True): """ Check if the server is alive. :param reconnect: If the connection is closed, reconnect. :raise Error: If the connection is closed and reconnect=False. """ if self._sock is None: if reconnect: self.connect() reconnect = False else: raise err.Error("Already closed") try: self._execute_command(COMMAND.COM_PING, "") self._read_ok_packet() except Exception: if reconnect: self.connect() self.ping(False) else: raise def set_charset(self, charset): # Make sure charset is supported. encoding = charset_by_name(charset).encoding self._execute_command(COMMAND.COM_QUERY, "SET NAMES %s" % self.escape(charset)) self._read_packet() self.charset = charset self.encoding = encoding def connect(self, sock=None): self._closed = False try: if sock is None: if self.unix_socket and self.host in ('localhost', '127.0.0.1'): sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) sock.settimeout(self.connect_timeout) sock.connect(self.unix_socket) self.host_info = "Localhost via UNIX socket" if DEBUG: print('connected using unix_socket') else: kwargs = {} if self.bind_address is not None: kwargs['source_address'] = (self.bind_address, 0) while True: try: sock = socket.create_connection( (self.host, self.port), self.connect_timeout, **kwargs) break except (OSError, IOError) as e: if e.errno == errno.EINTR: continue raise self.host_info = "socket %s:%d" % (self.host, self.port) if DEBUG: print('connected using socket') sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1) sock.settimeout(None) sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1) self._sock = sock self._rfile = _makefile(sock, 'rb') self._next_seq_id = 0 self._get_server_information() self._request_authentication() if self.sql_mode is not None: c = self.cursor() c.execute("SET sql_mode=%s", (self.sql_mode,)) if self.init_command is not None: c = self.cursor() c.execute(self.init_command) c.close() self.commit() if self.autocommit_mode is not None: self.autocommit(self.autocommit_mode) except BaseException as e: self._rfile = None if sock is not None: try: sock.close() except: pass if isinstance(e, (OSError, IOError, socket.error)): exc = err.OperationalError( 2003, "Can't connect to MySQL server on %r (%s)" % ( self.host, e)) # Keep original exception and traceback to investigate error. exc.original_exception = e exc.traceback = traceback.format_exc() if DEBUG: print(exc.traceback) raise exc # If e is neither DatabaseError or IOError, It's a bug. # But raising AssertionError hides original error. # So just reraise it. raise def write_packet(self, payload): """Writes an entire "mysql packet" in its entirety to the network addings its length and sequence number. """ # Internal note: when you build packet manualy and calls _write_bytes() # directly, you should set self._next_seq_id properly. data = pack_int24(len(payload)) + int2byte(self._next_seq_id) + payload if DEBUG: dump_packet(data) self._write_bytes(data) self._next_seq_id = (self._next_seq_id + 1) % 256 def _read_packet(self, packet_type=MysqlPacket): """Read an entire "mysql packet" in its entirety from the network and return a MysqlPacket type that represents the results. :raise OperationalError: If the connection to the MySQL server is lost. :raise InternalError: If the packet sequence number is wrong. """ buff = b'' while True: packet_header = self._read_bytes(4) #if DEBUG: dump_packet(packet_header) btrl, btrh, packet_number = struct.unpack('<HBB', packet_header) bytes_to_read = btrl + (btrh << 16) if packet_number != self._next_seq_id: self._force_close() if packet_number == 0: # MariaDB sends error packet with seqno==0 when shutdown raise err.OperationalError( CR.CR_SERVER_LOST, "Lost connection to MySQL server during query") raise err.InternalError( "Packet sequence number wrong - got %d expected %d" % (packet_number, self._next_seq_id)) self._next_seq_id = (self._next_seq_id + 1) % 256 recv_data = self._read_bytes(bytes_to_read) if DEBUG: dump_packet(recv_data) buff += recv_data # https://dev.mysql.com/doc/internals/en/sending-more-than-16mbyte.html if bytes_to_read == 0xffffff: continue if bytes_to_read < MAX_PACKET_LEN: break packet = packet_type(buff, self.encoding) packet.check_error() return packet def _read_bytes(self, num_bytes): self._sock.settimeout(self._read_timeout) while True: try: data = self._rfile.read(num_bytes) break except (IOError, OSError) as e: if e.errno == errno.EINTR: continue self._force_close() raise err.OperationalError( CR.CR_SERVER_LOST, "Lost connection to MySQL server during query (%s)" % (e,)) if len(data) < num_bytes: self._force_close() raise err.OperationalError( CR.CR_SERVER_LOST, "Lost connection to MySQL server during query") return data def _write_bytes(self, data): self._sock.settimeout(self._write_timeout) try: self._sock.sendall(data) except IOError as e: self._force_close() raise err.OperationalError( CR.CR_SERVER_GONE_ERROR, "MySQL server has gone away (%r)" % (e,)) def _read_query_result(self, unbuffered=False): self._result = None if unbuffered: try: result = MySQLResult(self) result.init_unbuffered_query() except: result.unbuffered_active = False result.connection = None raise else: result = MySQLResult(self) result.read() self._result = result if result.server_status is not None: self.server_status = result.server_status return result.affected_rows def insert_id(self): if self._result: return self._result.insert_id else: return 0 def _execute_command(self, command, sql): """ :raise InterfaceError: If the connection is closed. :raise ValueError: If no username was specified. """ if not self._sock: raise err.InterfaceError("(0, '')") # If the last query was unbuffered, make sure it finishes before # sending new commands if self._result is not None: if self._result.unbuffered_active: warnings.warn("Previous unbuffered result was left incomplete") self._result._finish_unbuffered_query() while self._result.has_next: self.next_result() self._result = None if isinstance(sql, text_type): sql = sql.encode(self.encoding) packet_size = min(MAX_PACKET_LEN, len(sql) + 1) # +1 is for command # tiny optimization: build first packet manually instead of # calling self..write_packet() prelude = struct.pack('<iB', packet_size, command) packet = prelude + sql[:packet_size-1] self._write_bytes(packet) if DEBUG: dump_packet(packet) self._next_seq_id = 1 if packet_size < MAX_PACKET_LEN: return sql = sql[packet_size-1:] while True: packet_size = min(MAX_PACKET_LEN, len(sql)) self.write_packet(sql[:packet_size]) sql = sql[packet_size:] if not sql and packet_size < MAX_PACKET_LEN: break def _request_authentication(self): # https://dev.mysql.com/doc/internals/en/connection-phase-packets.html#packet-Protocol::HandshakeResponse if int(self.server_version.split('.', 1)[0]) >= 5: self.client_flag |= CLIENT.MULTI_RESULTS if self.user is None: raise ValueError("Did not specify a username") charset_id = charset_by_name(self.charset).id if isinstance(self.user, text_type): self.user = self.user.encode(self.encoding) data_init = struct.pack('<iIB23s', self.client_flag, 1, charset_id, b'') if self.ssl and self.server_capabilities & CLIENT.SSL: self.write_packet(data_init) self._sock = self.ctx.wrap_socket(self._sock, server_hostname=self.host) self._rfile = _makefile(self._sock, 'rb') data = data_init + self.user + b'\0' authresp = b'' if self._auth_plugin_name in ('', 'mysql_native_password'): authresp = _scramble(self.password.encode('latin1'), self.salt) if self.server_capabilities & CLIENT.PLUGIN_AUTH_LENENC_CLIENT_DATA: data += lenenc_int(len(authresp)) + authresp elif self.server_capabilities & CLIENT.SECURE_CONNECTION: data += struct.pack('B', len(authresp)) + authresp else: # pragma: no cover - not testing against servers without secure auth (>=5.0) data += authresp + b'\0' if self.db and self.server_capabilities & CLIENT.CONNECT_WITH_DB: if isinstance(self.db, text_type): self.db = self.db.encode(self.encoding) data += self.db + b'\0' if self.server_capabilities & CLIENT.PLUGIN_AUTH: name = self._auth_plugin_name if isinstance(name, text_type): name = name.encode('ascii') data += name + b'\0' self.write_packet(data) auth_packet = self._read_packet() # if authentication method isn't accepted the first byte # will have the octet 254 if auth_packet.is_auth_switch_request(): # https://dev.mysql.com/doc/internals/en/connection-phase-packets.html#packet-Protocol::AuthSwitchRequest auth_packet.read_uint8() # 0xfe packet identifier plugin_name = auth_packet.read_string() if self.server_capabilities & CLIENT.PLUGIN_AUTH and plugin_name is not None: auth_packet = self._process_auth(plugin_name, auth_packet) else: # send legacy handshake data = _scramble_323(self.password.encode('latin1'), self.salt) + b'\0' self.write_packet(data) auth_packet = self._read_packet() def _process_auth(self, plugin_name, auth_packet): plugin_class = self._auth_plugin_map.get(plugin_name) if not plugin_class: plugin_class = self._auth_plugin_map.get(plugin_name.decode('ascii')) if plugin_class: try: handler = plugin_class(self) return handler.authenticate(auth_packet) except AttributeError: if plugin_name != b'dialog': raise err.OperationalError(2059, "Authentication plugin '%s'" \ " not loaded: - %r missing authenticate method" % (plugin_name, plugin_class)) except TypeError: raise err.OperationalError(2059, "Authentication plugin '%s'" \ " not loaded: - %r cannot be constructed with connection object" % (plugin_name, plugin_class)) else: handler = None if plugin_name == b"mysql_native_password": # https://dev.mysql.com/doc/internals/en/secure-password-authentication.html#packet-Authentication::Native41 data = _scramble(self.password.encode('latin1'), auth_packet.read_all()) elif plugin_name == b"mysql_old_password": # https://dev.mysql.com/doc/internals/en/old-password-authentication.html data = _scramble_323(self.password.encode('latin1'), auth_packet.read_all()) + b'\0' elif plugin_name == b"mysql_clear_password": # https://dev.mysql.com/doc/internals/en/clear-text-authentication.html data = self.password.encode('latin1') + b'\0' elif plugin_name == b"dialog": pkt = auth_packet while True: flag = pkt.read_uint8() echo = (flag & 0x06) == 0x02 last = (flag & 0x01) == 0x01 prompt = pkt.read_all() if prompt == b"Password: ": self.write_packet(self.password.encode('latin1') + b'\0') elif handler: resp = 'no response - TypeError within plugin.prompt method' try: resp = handler.prompt(echo, prompt) self.write_packet(resp + b'\0') except AttributeError: raise err.OperationalError(2059, "Authentication plugin '%s'" \ " not loaded: - %r missing prompt method" % (plugin_name, handler)) except TypeError: raise err.OperationalError(2061, "Authentication plugin '%s'" \ " %r didn't respond with string. Returned '%r' to prompt %r" % (plugin_name, handler, resp, prompt)) else: raise err.OperationalError(2059, "Authentication plugin '%s' (%r) not configured" % (plugin_name, handler)) pkt = self._read_packet() pkt.check_error() if pkt.is_ok_packet() or last: break return pkt else: raise err.OperationalError(2059, "Authentication plugin '%s' not configured" % plugin_name) self.write_packet(data) pkt = self._read_packet() pkt.check_error() return pkt # _mysql support def thread_id(self): return self.server_thread_id[0] def character_set_name(self): return self.charset def get_host_info(self): return self.host_info def get_proto_info(self): return self.protocol_version def _get_server_information(self): i = 0 packet = self._read_packet() data = packet.get_all_data() self.protocol_version = byte2int(data[i:i+1]) i += 1 server_end = data.find(b'\0', i) self.server_version = data[i:server_end].decode('latin1') i = server_end + 1 self.server_thread_id = struct.unpack('<I', data[i:i+4]) i += 4 self.salt = data[i:i+8] i += 9 # 8 + 1(filler) self.server_capabilities = struct.unpack('<H', data[i:i+2])[0] i += 2 if len(data) >= i + 6: lang, stat, cap_h, salt_len = struct.unpack('<BHHB', data[i:i+6]) i += 6 # TODO: deprecate server_language and server_charset. # mysqlclient-python doesn't provide it. self.server_language = lang try: self.server_charset = charset_by_id(lang).name except KeyError: # unknown collation self.server_charset = None self.server_status = stat if DEBUG: print("server_status: %x" % stat) self.server_capabilities |= cap_h << 16 if DEBUG: print("salt_len:", salt_len) salt_len = max(12, salt_len - 9) # reserved i += 10 if len(data) >= i + salt_len: # salt_len includes auth_plugin_data_part_1 and filler self.salt += data[i:i+salt_len] i += salt_len i+=1 # AUTH PLUGIN NAME may appear here. if self.server_capabilities & CLIENT.PLUGIN_AUTH and len(data) >= i: # Due to Bug#59453 the auth-plugin-name is missing the terminating # NUL-char in versions prior to 5.5.10 and 5.6.2. # ref: https://dev.mysql.com/doc/internals/en/connection-phase-packets.html#packet-Protocol::Handshake # didn't use version checks as mariadb is corrected and reports # earlier than those two. server_end = data.find(b'\0', i) if server_end < 0: # pragma: no cover - very specific upstream bug # not found \0 and last field so take it all self._auth_plugin_name = data[i:].decode('latin1') else: self._auth_plugin_name = data[i:server_end].decode('latin1') def get_server_info(self): return self.server_version Warning = err.Warning Error = err.Error InterfaceError = err.InterfaceError DatabaseError = err.DatabaseError DataError = err.DataError OperationalError = err.OperationalError IntegrityError = err.IntegrityError InternalError = err.InternalError ProgrammingError = err.ProgrammingError NotSupportedError = err.NotSupportedError
https://github.com/PyMySQL/PyMySQL/blob/master/pymysql/cursors.py
class Cursor(object): """ This is the object you use to interact with the database. Do not create an instance of a Cursor yourself. Call connections.Connection.cursor(). See `Cursor <https://www.python.org/dev/peps/pep-0249/#cursor-objects>`_ in the specification. """ #: Max statement size which :meth:`executemany` generates. #: #: Max size of allowed statement is max_allowed_packet - packet_header_size. #: Default value of max_allowed_packet is 1048576. max_stmt_length = 1024000 _defer_warnings = False def __init__(self, connection): self.connection = connection self.description = None self.rownumber = 0 self.rowcount = -1 self.arraysize = 1 self._executed = None self._result = None self._rows = None self._warnings_handled = False def close(self): """ Closing a cursor just exhausts all remaining data. """ conn = self.connection if conn is None: return try: while self.nextset(): pass finally: self.connection = None def __enter__(self): return self def __exit__(self, *exc_info): del exc_info self.close() def _get_db(self): if not self.connection: raise err.ProgrammingError("Cursor closed") return self.connection def _check_executed(self): if not self._executed: raise err.ProgrammingError("execute() first") def _conv_row(self, row): return row def setinputsizes(self, *args): """Does nothing, required by DB API.""" def setoutputsizes(self, *args): """Does nothing, required by DB API.""" def _nextset(self, unbuffered=False): """Get the next query set""" conn = self._get_db() current_result = self._result # for unbuffered queries warnings are only available once whole result has been read if unbuffered: self._show_warnings() if current_result is None or current_result is not conn._result: return None if not current_result.has_next: return None self._result = None self._clear_result() conn.next_result(unbuffered=unbuffered) self._do_get_result() return True def nextset(self): return self._nextset(False) def _ensure_bytes(self, x, encoding=None): if isinstance(x, text_type): x = x.encode(encoding) elif isinstance(x, (tuple, list)): x = type(x)(self._ensure_bytes(v, encoding=encoding) for v in x) return x def _escape_args(self, args, conn): ensure_bytes = partial(self._ensure_bytes, encoding=conn.encoding) if isinstance(args, (tuple, list)): if PY2: args = tuple(map(ensure_bytes, args)) return tuple(conn.literal(arg) for arg in args) elif isinstance(args, dict): if PY2: args = dict((ensure_bytes(key), ensure_bytes(val)) for (key, val) in args.items()) return dict((key, conn.literal(val)) for (key, val) in args.items()) else: # If it's not a dictionary let's try escaping it anyways. # Worst case it will throw a Value error if PY2: args = ensure_bytes(args) return conn.escape(args) def mogrify(self, query, args=None): """ Returns the exact string that is sent to the database by calling the execute() method. This method follows the extension to the DB API 2.0 followed by Psycopg. """ conn = self._get_db() if PY2: # Use bytes on Python 2 always query = self._ensure_bytes(query, encoding=conn.encoding) if args is not None: query = query % self._escape_args(args, conn) return query def execute(self, query, args=None): """Execute a query :param str query: Query to execute. :param args: parameters used with query. (optional) :type args: tuple, list or dict :return: Number of affected rows :rtype: int If args is a list or tuple, %s can be used as a placeholder in the query. If args is a dict, %(name)s can be used as a placeholder in the query. """ while self.nextset(): pass query = self.mogrify(query, args) result = self._query(query) self._executed = query return result def executemany(self, query, args): # type: (str, list) -> int """Run several data against one query :param query: query to execute on server :param args: Sequence of sequences or mappings. It is used as parameter. :return: Number of rows affected, if any. This method improves performance on multiple-row INSERT and REPLACE. Otherwise it is equivalent to looping over args with execute(). """ if not args: return m = RE_INSERT_VALUES.match(query) if m: q_prefix = m.group(1) % () q_values = m.group(2).rstrip() q_postfix = m.group(3) or '' assert q_values[0] == '(' and q_values[-1] == ')' return self._do_execute_many(q_prefix, q_values, q_postfix, args, self.max_stmt_length, self._get_db().encoding) self.rowcount = sum(self.execute(query, arg) for arg in args) return self.rowcount def _do_execute_many(self, prefix, values, postfix, args, max_stmt_length, encoding): conn = self._get_db() escape = self._escape_args if isinstance(prefix, text_type): prefix = prefix.encode(encoding) if PY2 and isinstance(values, text_type): values = values.encode(encoding) if isinstance(postfix, text_type): postfix = postfix.encode(encoding) sql = bytearray(prefix) args = iter(args) v = values % escape(next(args), conn) if isinstance(v, text_type): if PY2: v = v.encode(encoding) else: v = v.encode(encoding, 'surrogateescape') sql += v rows = 0 for arg in args: v = values % escape(arg, conn) if isinstance(v, text_type): if PY2: v = v.encode(encoding) else: v = v.encode(encoding, 'surrogateescape') if len(sql) + len(v) + len(postfix) + 1 > max_stmt_length: rows += self.execute(sql + postfix) sql = bytearray(prefix) else: sql += b',' sql += v rows += self.execute(sql + postfix) self.rowcount = rows return rows def callproc(self, procname, args=()): """Execute stored procedure procname with args procname -- string, name of procedure to execute on server args -- Sequence of parameters to use with procedure Returns the original args. Compatibility warning: PEP-249 specifies that any modified parameters must be returned. This is currently impossible as they are only available by storing them in a server variable and then retrieved by a query. Since stored procedures return zero or more result sets, there is no reliable way to get at OUT or INOUT parameters via callproc. The server variables are named @_procname_n, where procname is the parameter above and n is the position of the parameter (from zero). Once all result sets generated by the procedure have been fetched, you can issue a SELECT @_procname_0, ... query using .execute() to get any OUT or INOUT values. Compatibility warning: The act of calling a stored procedure itself creates an empty result set. This appears after any result sets generated by the procedure. This is non-standard behavior with respect to the DB-API. Be sure to use nextset() to advance through all result sets; otherwise you may get disconnected. """ conn = self._get_db() if args: fmt = '@_{0}_%d=%s'.format(procname) self._query('SET %s' % ','.join(fmt % (index, conn.escape(arg)) for index, arg in enumerate(args))) self.nextset() q = "CALL %s(%s)" % (procname, ','.join(['@_%s_%d' % (procname, i) for i in range_type(len(args))])) self._query(q) self._executed = q return args def fetchone(self): """Fetch the next row""" self._check_executed() if self._rows is None or self.rownumber >= len(self._rows): return None result = self._rows[self.rownumber] self.rownumber += 1 return result def fetchmany(self, size=None): """Fetch several rows""" self._check_executed() if self._rows is None: return () end = self.rownumber + (size or self.arraysize) result = self._rows[self.rownumber:end] self.rownumber = min(end, len(self._rows)) return result def fetchall(self): """Fetch all the rows""" self._check_executed() if self._rows is None: return () if self.rownumber: result = self._rows[self.rownumber:] else: result = self._rows self.rownumber = len(self._rows) return result def scroll(self, value, mode='relative'): self._check_executed() if mode == 'relative': r = self.rownumber + value elif mode == 'absolute': r = value else: raise err.ProgrammingError("unknown scroll mode %s" % mode) if not (0 <= r < len(self._rows)): raise IndexError("out of range") self.rownumber = r def _query(self, q): conn = self._get_db() self._last_executed = q self._clear_result() conn.query(q) self._do_get_result() return self.rowcount def _clear_result(self): self.rownumber = 0 self._result = None self.rowcount = 0 self.description = None self.lastrowid = None self._rows = None def _do_get_result(self): conn = self._get_db() self._result = result = conn._result self.rowcount = result.affected_rows self.description = result.description self.lastrowid = result.insert_id self._rows = result.rows self._warnings_handled = False if not self._defer_warnings: self._show_warnings() def _show_warnings(self): if self._warnings_handled: return self._warnings_handled = True if self._result and (self._result.has_next or not self._result.warning_count): return ws = self._get_db().show_warnings() if ws is None: return for w in ws: msg = w[-1] if PY2: if isinstance(msg, unicode): msg = msg.encode('utf-8', 'replace') warnings.warn(err.Warning(*w[1:3]), stacklevel=4) def __iter__(self): return iter(self.fetchone, None) Warning = err.Warning Error = err.Error InterfaceError = err.InterfaceError DatabaseError = err.DatabaseError DataError = err.DataError OperationalError = err.OperationalError IntegrityError = err.IntegrityError InternalError = err.InternalError ProgrammingError = err.ProgrammingError NotSupportedError = err.NotSupportedError
def fetchone(self): """Fetch the next row""" self._check_executed() if self._rows is None or self.rownumber >= len(self._rows): return None result = self._rows[self.rownumber] self.rownumber += 1 return result def fetchmany(self, size=None): """Fetch several rows""" self._check_executed() if self._rows is None: return () end = self.rownumber + (size or self.arraysize) result = self._rows[self.rownumber:end] self.rownumber = min(end, len(self._rows)) return result