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