morro

sqlalchemy/dialects/mysql/pyodbc.py

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+"""Support for the MySQL database via the pyodbc adapter.
+
+pyodbc is available at:
+
+    http://pypi.python.org/pypi/pyodbc/
+
+Connecting
+----------
+
+Connect string::
+
+    mysql+pyodbc://<username>:<password>@<dsnname>
+
+Limitations
+-----------
+
+The mysql-pyodbc dialect is subject to unresolved character encoding issues 
+which exist within the current ODBC drivers available.
+(see http://code.google.com/p/pyodbc/issues/detail?id=25).   Consider usage
+of OurSQL, MySQLdb, or MySQL-connector/Python.
+
+"""
+
+from sqlalchemy.dialects.mysql.base import MySQLDialect, MySQLExecutionContext
+from sqlalchemy.connectors.pyodbc import PyODBCConnector
+from sqlalchemy.engine import base as engine_base
+from sqlalchemy import util
+import re
+
+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_unicode_statements = False
+    execution_ctx_cls = MySQLExecutionContext_pyodbc
+
+    pyodbc_driver_name = "MySQL"
+    
+    def __init__(self, **kw):
+        # deal with http://code.google.com/p/pyodbc/issues/detail?id=25
+        kw.setdefault('convert_unicode', True)
+        super(MySQLDialect_pyodbc, self).__init__(**kw)
+
+    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.execute("SHOW VARIABLES LIKE 'character_set%%'")
+        opts = dict([(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.orig.args))
+        c = m.group(1)
+        if c:
+            return int(c)
+        else:
+            return None
+
+dialect = MySQLDialect_pyodbc