# dialects/mysql/pymysql.py
# Copyright (C) 2005-2025 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: https://www.opensource.org/licenses/mit-license.php
# mypy: ignore-errors
r"""
.. dialect:: mysql+pymysql
:name: PyMySQL
:dbapi: pymysql
:connectstring: mysql+pymysql://<username>:<password>@<host>/<dbname>[?<options>]
:url: https://pymysql.readthedocs.io/
Unicode
-------
Please see :ref:`mysql_unicode` for current recommendations on unicode
handling.
.. _pymysql_ssl:
SSL Connections
------------------
The PyMySQL DBAPI accepts the same SSL arguments as that of MySQLdb,
described at :ref:`mysqldb_ssl`. See that section for additional examples.
If the server uses an automatically-generated certificate that is self-signed
or does not match the host name (as seen from the client), it may also be
necessary to indicate ``ssl_check_hostname=false`` in PyMySQL::
connection_uri = (
"mysql+pymysql://scott:tiger@192.168.0.134/test"
"?ssl_ca=/home/gord/client-ssl/ca.pem"
"&ssl_cert=/home/gord/client-ssl/client-cert.pem"
"&ssl_key=/home/gord/client-ssl/client-key.pem"
"&ssl_check_hostname=false"
)
MySQL-Python Compatibility
--------------------------
The pymysql DBAPI is a pure Python port of the MySQL-python (MySQLdb) driver,
and targets 100% compatibility. Most behavioral notes for MySQL-python apply
to the pymysql driver as well.
""" # noqa
from .mysqldb import MySQLDialect_mysqldb
from ...util import langhelpers
class MySQLDialect_pymysql(MySQLDialect_mysqldb):
driver = "pymysql"
supports_statement_cache = True
description_encoding = None
@langhelpers.memoized_property
def supports_server_side_cursors(self):
try:
cursors = __import__("pymysql.cursors").cursors
self._sscursor = cursors.SSCursor
return True
except (ImportError, AttributeError):
return False
@classmethod
def import_dbapi(cls):
return __import__("pymysql")
@langhelpers.memoized_property
def _send_false_to_ping(self):
"""determine if pymysql has deprecated, changed the default of,
or removed the 'reconnect' argument of connection.ping().
See #10492 and
https://github.com/PyMySQL/mysqlclient/discussions/651#discussioncomment-7308971
for background.
""" # noqa: E501
try:
Connection = __import__(
"pymysql.connections"
).connections.Connection
except (ImportError, AttributeError):
return True
else:
insp = langhelpers.get_callable_argspec(Connection.ping)
try:
reconnect_arg = insp.args[1]
except IndexError:
return False
else:
return reconnect_arg == "reconnect" and (
not insp.defaults or insp.defaults[0] is not False
)
def do_ping(self, dbapi_connection):
if self._send_false_to_ping:
dbapi_connection.ping(False)
else:
dbapi_connection.ping()
return True
def create_connect_args(self, url, _translate_args=None):
if _translate_args is None:
_translate_args = dict(username="user")
return super().create_connect_args(
url, _translate_args=_translate_args
)
def is_disconnect(self, e, connection, cursor):
if super().is_disconnect(e, connection, cursor):
return True
elif isinstance(e, self.dbapi.Error):
str_e = str(e).lower()
return (
"already closed" in str_e or "connection was killed" in str_e
)
else:
return False
def _extract_error_code(self, exception):
if isinstance(exception.args[0], Exception):
exception = exception.args[0]
return exception.args[0]
dialect = MySQLDialect_pymysql
|