OpenHome/venv/Lib/site-packages/sqlalchemy/dialects/mysql/pyodbc.py
2021-07-21 21:33:05 +02:00

138 lines
4.4 KiB
Python

# mysql/pyodbc.py
# Copyright (C) 2005-2021 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
r"""
.. dialect:: mysql+pyodbc
:name: PyODBC
:dbapi: pyodbc
:connectstring: mysql+pyodbc://<username>:<password>@<dsnname>
:url: http://pypi.python.org/pypi/pyodbc/
.. note::
The PyODBC for MySQL dialect is **not tested as part of
SQLAlchemy's continuous integration**.
The recommended MySQL dialects are mysqlclient and PyMySQL.
However, if you want to use the mysql+pyodbc dialect and require
full support for ``utf8mb4`` characters (including supplementary
characters like emoji) be sure to use a current release of
MySQL Connector/ODBC and specify the "ANSI" (**not** "Unicode")
version of the driver in your DSN or connection string.
Pass through exact pyodbc connection string::
import urllib
connection_string = (
'DRIVER=MySQL ODBC 8.0 ANSI Driver;'
'SERVER=localhost;'
'PORT=3307;'
'DATABASE=mydb;'
'UID=root;'
'PWD=(whatever);'
'charset=utf8mb4;'
)
params = urllib.parse.quote_plus(connection_string)
connection_uri = "mysql+pyodbc:///?odbc_connect=%s" % params
""" # noqa
import re
import sys
from .base import MySQLDialect
from .base import MySQLExecutionContext
from .types import TIME
from ... import util
from ...connectors.pyodbc import PyODBCConnector
from ...sql.sqltypes import Time
class _pyodbcTIME(TIME):
def result_processor(self, dialect, coltype):
def process(value):
# pyodbc returns a datetime.time object; no need to convert
return value
return process
class MySQLExecutionContext_pyodbc(MySQLExecutionContext):
def get_lastrowid(self):
cursor = self.create_cursor()
cursor.execute("SELECT LAST_INSERT_ID()")
lastrowid = cursor.fetchone()[0]
cursor.close()
return lastrowid
class MySQLDialect_pyodbc(PyODBCConnector, MySQLDialect):
supports_statement_cache = True
colspecs = util.update_copy(MySQLDialect.colspecs, {Time: _pyodbcTIME})
supports_unicode_statements = True
execution_ctx_cls = MySQLExecutionContext_pyodbc
pyodbc_driver_name = "MySQL"
def _detect_charset(self, connection):
"""Sniff out the character set in use for connection results."""
# Prefer 'character_set_results' for the current connection over the
# value in the driver. SET NAMES or individual variable SETs will
# change the charset without updating the driver's view of the world.
#
# If it's decided that issuing that sort of SQL leaves you SOL, then
# this can prefer the driver value.
rs = connection.exec_driver_sql(
"SHOW VARIABLES LIKE 'character_set%%'"
)
opts = {row[0]: row[1] for row in self._compat_fetchall(rs)}
for key in ("character_set_connection", "character_set"):
if opts.get(key, None):
return opts[key]
util.warn(
"Could not detect the connection character set. "
"Assuming latin1."
)
return "latin1"
def _extract_error_code(self, exception):
m = re.compile(r"\((\d+)\)").search(str(exception.args))
c = m.group(1)
if c:
return int(c)
else:
return None
def on_connect(self):
super_ = super(MySQLDialect_pyodbc, self).on_connect()
def on_connect(conn):
if super_ is not None:
super_(conn)
# declare Unicode encoding for pyodbc as per
# https://github.com/mkleehammer/pyodbc/wiki/Unicode
pyodbc_SQL_CHAR = 1 # pyodbc.SQL_CHAR
pyodbc_SQL_WCHAR = -8 # pyodbc.SQL_WCHAR
if sys.version_info.major > 2:
conn.setdecoding(pyodbc_SQL_CHAR, encoding="utf-8")
conn.setdecoding(pyodbc_SQL_WCHAR, encoding="utf-8")
conn.setencoding(encoding="utf-8")
else:
conn.setdecoding(pyodbc_SQL_CHAR, encoding="utf-8")
conn.setdecoding(pyodbc_SQL_WCHAR, encoding="utf-8")
conn.setencoding(str, encoding="utf-8")
conn.setencoding(unicode, encoding="utf-8") # noqa: F821
return on_connect
dialect = MySQLDialect_pyodbc