# sybase/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
"""
.. dialect:: sybase+pyodbc
:name: PyODBC
:dbapi: pyodbc
:connectstring: sybase+pyodbc://<username>:<password>@<dsnname>[/<database>]
:url: http://pypi.python.org/pypi/pyodbc/
Unicode Support
---------------
The pyodbc driver currently supports usage of these Sybase types with
Unicode or multibyte strings::
CHAR
NCHAR
NVARCHAR
TEXT
VARCHAR
Currently *not* supported are::
UNICHAR
UNITEXT
UNIVARCHAR
""" # noqa
import decimal
from sqlalchemy import processors
from sqlalchemy import types as sqltypes
from sqlalchemy.connectors.pyodbc import PyODBCConnector
from sqlalchemy.dialects.sybase.base import SybaseDialect
from sqlalchemy.dialects.sybase.base import SybaseExecutionContext
class _SybNumeric_pyodbc(sqltypes.Numeric):
"""Turns Decimals with adjusted() < -6 into floats.
It's not yet known how to get decimals with many
significant digits or very large adjusted() into Sybase
via pyodbc.
"""
def bind_processor(self, dialect):
super_process = super(_SybNumeric_pyodbc, self).bind_processor(dialect)
def process(value):
if self.asdecimal and isinstance(value, decimal.Decimal):
if value.adjusted() < -6:
return processors.to_float(value)
if super_process:
return super_process(value)
else:
return value
return process
class SybaseExecutionContext_pyodbc(SybaseExecutionContext):
def set_ddl_autocommit(self, connection, value):
if value:
connection.autocommit = True
else:
connection.autocommit = False
class SybaseDialect_pyodbc(PyODBCConnector, SybaseDialect):
execution_ctx_cls = SybaseExecutionContext_pyodbc
colspecs = {sqltypes.Numeric: _SybNumeric_pyodbc}
dialect = SybaseDialect_pyodbc
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