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252
venv/Lib/site-packages/sqlalchemy/dialects/mysql/mysqldb.py
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252
venv/Lib/site-packages/sqlalchemy/dialects/mysql/mysqldb.py
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# mysql/mysqldb.py
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# Copyright (C) 2005-2019 the SQLAlchemy authors and contributors
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# <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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"""
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.. dialect:: mysql+mysqldb
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:name: mysqlclient (maintained fork of MySQL-Python)
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:dbapi: mysqldb
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:connectstring: mysql+mysqldb://<user>:<password>@<host>[:<port>]/<dbname>
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:url: https://pypi.org/project/mysqlclient/
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Driver Status
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-------------
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The mysqlclient DBAPI is a maintained fork of the
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`MySQL-Python <http://sourceforge.net/projects/mysql-python>`_ DBAPI
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that is no longer maintained. `mysqlclient`_ supports Python 2 and Python 3
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and is very stable.
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.. _mysqlclient: https://github.com/PyMySQL/mysqlclient-python
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.. _mysqldb_unicode:
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Unicode
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-------
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Please see :ref:`mysql_unicode` for current recommendations on unicode
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handling.
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Using MySQLdb with Google Cloud SQL
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-----------------------------------
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Google Cloud SQL now recommends use of the MySQLdb dialect. Connect
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using a URL like the following::
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mysql+mysqldb://root@/<dbname>?unix_socket=/cloudsql/<projectid>:<instancename>
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Server Side Cursors
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-------------------
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The mysqldb dialect supports server-side cursors. See :ref:`mysql_ss_cursors`.
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"""
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import re
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from .base import MySQLCompiler
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from .base import MySQLDialect
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from .base import MySQLExecutionContext
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from .base import MySQLIdentifierPreparer
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from .base import TEXT
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from ... import sql
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from ... import util
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class MySQLExecutionContext_mysqldb(MySQLExecutionContext):
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@property
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def rowcount(self):
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if hasattr(self, "_rowcount"):
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return self._rowcount
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else:
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return self.cursor.rowcount
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class MySQLCompiler_mysqldb(MySQLCompiler):
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pass
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class MySQLIdentifierPreparer_mysqldb(MySQLIdentifierPreparer):
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pass
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class MySQLDialect_mysqldb(MySQLDialect):
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driver = "mysqldb"
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supports_unicode_statements = True
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supports_sane_rowcount = True
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supports_sane_multi_rowcount = True
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supports_native_decimal = True
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default_paramstyle = "format"
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execution_ctx_cls = MySQLExecutionContext_mysqldb
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statement_compiler = MySQLCompiler_mysqldb
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preparer = MySQLIdentifierPreparer_mysqldb
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def __init__(self, server_side_cursors=False, **kwargs):
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super(MySQLDialect_mysqldb, self).__init__(**kwargs)
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self.server_side_cursors = server_side_cursors
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self._mysql_dbapi_version = (
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self._parse_dbapi_version(self.dbapi.__version__)
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if self.dbapi is not None and hasattr(self.dbapi, "__version__")
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else (0, 0, 0)
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)
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def _parse_dbapi_version(self, version):
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m = re.match(r"(\d+)\.(\d+)(?:\.(\d+))?", version)
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if m:
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return tuple(int(x) for x in m.group(1, 2, 3) if x is not None)
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else:
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return (0, 0, 0)
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@util.langhelpers.memoized_property
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def supports_server_side_cursors(self):
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try:
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cursors = __import__("MySQLdb.cursors").cursors
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self._sscursor = cursors.SSCursor
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return True
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except (ImportError, AttributeError):
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return False
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@classmethod
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def dbapi(cls):
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return __import__("MySQLdb")
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def do_ping(self, dbapi_connection):
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try:
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dbapi_connection.ping(False)
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except self.dbapi.Error as err:
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if self.is_disconnect(err, dbapi_connection, None):
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return False
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else:
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raise
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else:
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return True
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def do_executemany(self, cursor, statement, parameters, context=None):
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rowcount = cursor.executemany(statement, parameters)
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if context is not None:
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context._rowcount = rowcount
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def _check_unicode_returns(self, connection):
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# work around issue fixed in
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# https://github.com/farcepest/MySQLdb1/commit/cd44524fef63bd3fcb71947392326e9742d520e8
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# specific issue w/ the utf8mb4_bin collation and unicode returns
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has_utf8mb4_bin = self.server_version_info > (
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5,
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) and connection.scalar(
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"show collation where %s = 'utf8mb4' and %s = 'utf8mb4_bin'"
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% (
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self.identifier_preparer.quote("Charset"),
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self.identifier_preparer.quote("Collation"),
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)
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)
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if has_utf8mb4_bin:
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additional_tests = [
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sql.collate(
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sql.cast(
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sql.literal_column("'test collated returns'"),
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TEXT(charset="utf8mb4"),
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),
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"utf8mb4_bin",
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)
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]
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else:
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additional_tests = []
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return super(MySQLDialect_mysqldb, self)._check_unicode_returns(
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connection, additional_tests
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)
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def create_connect_args(self, url):
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opts = url.translate_connect_args(
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database="db", username="user", password="passwd"
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)
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opts.update(url.query)
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util.coerce_kw_type(opts, "compress", bool)
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util.coerce_kw_type(opts, "connect_timeout", int)
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util.coerce_kw_type(opts, "read_timeout", int)
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util.coerce_kw_type(opts, "write_timeout", int)
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util.coerce_kw_type(opts, "client_flag", int)
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util.coerce_kw_type(opts, "local_infile", int)
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# Note: using either of the below will cause all strings to be
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# returned as Unicode, both in raw SQL operations and with column
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# types like String and MSString.
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util.coerce_kw_type(opts, "use_unicode", bool)
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util.coerce_kw_type(opts, "charset", str)
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# Rich values 'cursorclass' and 'conv' are not supported via
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# query string.
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ssl = {}
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keys = ["ssl_ca", "ssl_key", "ssl_cert", "ssl_capath", "ssl_cipher"]
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for key in keys:
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if key in opts:
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ssl[key[4:]] = opts[key]
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util.coerce_kw_type(ssl, key[4:], str)
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del opts[key]
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if ssl:
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opts["ssl"] = ssl
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# FOUND_ROWS must be set in CLIENT_FLAGS to enable
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# supports_sane_rowcount.
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client_flag = opts.get("client_flag", 0)
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if self.dbapi is not None:
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try:
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CLIENT_FLAGS = __import__(
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self.dbapi.__name__ + ".constants.CLIENT"
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).constants.CLIENT
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client_flag |= CLIENT_FLAGS.FOUND_ROWS
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except (AttributeError, ImportError):
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self.supports_sane_rowcount = False
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opts["client_flag"] = client_flag
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return [[], opts]
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def _extract_error_code(self, exception):
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return exception.args[0]
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def _detect_charset(self, connection):
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"""Sniff out the character set in use for connection results."""
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try:
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# note: the SQL here would be
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# "SHOW VARIABLES LIKE 'character_set%%'"
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cset_name = connection.connection.character_set_name
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except AttributeError:
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util.warn(
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"No 'character_set_name' can be detected with "
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"this MySQL-Python version; "
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"please upgrade to a recent version of MySQL-Python. "
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"Assuming latin1."
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)
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return "latin1"
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else:
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return cset_name()
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_isolation_lookup = set(
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[
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"SERIALIZABLE",
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"READ UNCOMMITTED",
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"READ COMMITTED",
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"REPEATABLE READ",
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"AUTOCOMMIT",
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]
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)
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def _set_isolation_level(self, connection, level):
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if level == "AUTOCOMMIT":
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connection.autocommit(True)
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else:
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connection.autocommit(False)
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super(MySQLDialect_mysqldb, self)._set_isolation_level(
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connection, level
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)
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dialect = MySQLDialect_mysqldb
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