Update 2025-04-13_16:25:39

venv/lib/python3.11/site-packages/sqlalchemy/dialects/mysql/pyodbc.py

@@ -0,0 +1,139 @@
+# dialects/mysql/pyodbc.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+pyodbc
+    :name: PyODBC
+    :dbapi: pyodbc
+    :connectstring: mysql+pyodbc://<username>:<password>@<dsnname>
+    :url: https://pypi.org/project/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
+
+from .base import MySQLDialect
+from .base import MySQLExecutionContext
+from .types import TIME
+from ... import exc
+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.
+
+        # set this to None as _fetch_setting attempts to use it (None is OK)
+        self._connection_charset = None
+        try:
+            value = self._fetch_setting(connection, "character_set_client")
+            if value:
+                return value
+        except exc.DBAPIError:
+            pass
+
+        util.warn(
+            "Could not detect the connection character set.  "
+            "Assuming latin1."
+        )
+        return "latin1"
+
+    def _get_server_version_info(self, connection):
+        return MySQLDialect._get_server_version_info(self, connection)
+
+    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().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
+            conn.setdecoding(pyodbc_SQL_CHAR, encoding="utf-8")
+            conn.setdecoding(pyodbc_SQL_WCHAR, encoding="utf-8")
+            conn.setencoding(encoding="utf-8")
+
+        return on_connect
+
+
+dialect = MySQLDialect_pyodbc