Pymssql

===========================================

Features
--------

- Custom message handlers (GH-139)

The DB-Library API includes a callback mechanism so applications can provide
functions known as *message handlers* that get passed informative messages
sent by the server which then can be logged, shown to the user, etc.

``_mssql`` now allows you to install your own *message handlers* written in
Python. See the ``_msssql`` examples and reference sections of the
documentation for more details.

Thanks Marc Abramowitz.

- Compatibility with Azure

It is now possible to transparently connect to `SQL Server instances`_
accessible as part of the Azure_ cloud services.

.. note:: If you need to connect to Azure make sure you use FreeTDS 0.91 or
newer.

- Customizable per-connection initialization SQL clauses (both in ``pymssql``
and ``_mssql``) (GH-97)

It is now possible to customize the SQL statements sent right after the
connection is established (e.g. ``'SET ANSI_NULLS ON;'``). Previously
it was a hard-coded list of queries. See the ``_mssql.MSSQLConnection``
documentation for more details.

Thanks Marc Abramowitz.

- Added ability to handle instances of ``uuid.UUID`` passed as parameters for
SQL queries both in ``pymssql`` and ``_mssql``. (GH-209)

Thanks Marat Mavlyutov.

- Allow using `SQL Server autocommit mode`_ from ``pymssql`` at connection
opening time. This allows e.g. DDL statements like ``DROP DATABASE`` to be
executed. (GH-210)

Thanks Marat Mavlyutov.

- Documentation: Explicitly mention minimum versions supported of Python (2.6)
and SQL Server (2005).

- Incremental enhancements to the documentation.

.. _SQL Server instances: http://www.windowsazure.com/en-us/services/sql-database/
.. _Azure: https://www.windowsazure.com/
.. _SQL Server autocommit mode: http://msdn.microsoft.com/en-us/library/ms187878%28v=sql.105%29.aspx

Bug fixes
---------

- Handle errors when calling Stored Procedures via the ``.callproc()`` pymssql
cursor method. Now it will raise a DB-API ``DatabaseException``; previously
it allowed a ``_mssql.MSSQLDatabaseException`` exception to surface.

- Fixes in ``tds_version`` ``_mssql`` connections property value

Made it work with TDS protocol version 7.2. (GH-211)

The value returned for TDS version 7.1 is still 8.0 for backward
compatibility (this is because such feature got added in times when
Microsoft documentation labeled the two protocol versions that followed 7.0
as 8.0 and 9.0; later it changed them to 7.1 and 7.2 respectively) and will
be corrected in a future release (2.2).

- PEP 249 compliance (GH-251)

Added type constructors to increase compatibility with other libraries.

Thanks Aymeric Augustin.

- pymssql: Made handling of integer SP params more robust (GH-237)

- Check lower bound value when convering integer values from to Python to SQL
(GH-238)

Internals
---------

- Completed migration of the test suite from nose to py.test.

- Added a few more test cases to our suite.

- Tests: Modified a couple of test cases so the full suite can be run against
SQL Server 2005.

- Added testing of successful build of documentation to Travis CI script.

- Build process: Cleanup intermediate and ad-hoc anciliary files (GH-231,
GH-273)

- setup.py: Fixed handling of release tarballs contents so no extraneous files
are shipped and the documentation tree is actually included. Also, removed
unused code.

=============================================================================

Features
--------

- Sphinx-based documentation (GH-149)

Read it online at http://pymssql.org/

Thanks, Ramiro Morales!

See:

* https://github.com/pymssql/pymssql/pull/149
* https://github.com/pymssql/pymssql/pull/162
* https://github.com/pymssql/pymssql/pull/164
* https://github.com/pymssql/pymssql/pull/165
* https://github.com/pymssql/pymssql/pull/166
* https://github.com/pymssql/pymssql/pull/167
* https://github.com/pymssql/pymssql/pull/169
* https://github.com/pymssql/pymssql/pull/174
* https://github.com/pymssql/pymssql/pull/175

- "Green" support (GH-135)

Lets you use pymssql with cooperative multi-tasking systems like
gevent and have pymssql call a callback when it is waiting for a
response from the server. You can set this callback to yield to
another greenlet, coroutine, etc. For example, for gevent, you could
do::

def wait_callback(read_fileno):
gevent.socket.wait_read(read_fileno)

pymssql.set_wait_callback(wait_callback)

The above is useful if you're say, running a gunicorn server with the
gevent worker. With this callback in place, when you send a query to
SQL server and are waiting for a response, you can yield to other
greenlets and process other requests. This is super useful when you
have high concurrency and/or slow database queries and lets you use
less gunicorn worker processes and still handle high concurrency.

See https://github.com/pymssql/pymssql/pull/135

- Better error messages.

E.g.: For a connection failure, instead of:

pymssql.OperationalError: (20009, 'Net-Lib error during Connection
refused')

the dberrstr is also included, resulting in:

pymssql.OperationalError: (20009, 'DB-Lib error message 20009,
severity 9:\nUnable to connect: Adaptive Server is unavailable or
does not exist\nNet-Lib error during Connection refused\n')

See:
* https://github.com/pymssql/pymssql/pull/151

In the area of error messages, we also made this change:

execute: Raise ColumnsWithoutNamesError when as_dict=True and missing
column names (GH-160)

because the previous behavior was very confusing; instead of raising
an exception, we would just return row dicts with those columns
missing. This prompted at least one question on the mailing list
(https://groups.google.com/forum/?fromgroups#!topic/pymssql/JoZpmNZFtxM),
so we thought it was better to handle this explicitly by raising an
exception, so the user would understand what went wrong.

See:
* https://github.com/pymssql/pymssql/pull/160
* https://github.com/pymssql/pymssql/pull/168

- Performance improvements

You are most likely to notice a difference from these when you are
fetching a large number of rows.

* Reworked row fetching (GH-159)

There was a rather large amount of type conversion occuring when
fetching a row from pymssql. The number of conversions required have
been cut down significantly with these changes.
Thanks Damien, Churchill!

See:
* https://github.com/pymssql/pymssql/pull/158
* https://github.com/pymssql/pymssql/pull/159

* Modify get_row() to use the CPython tuple API (GH-178)

This drops the previous method of building up a row tuple and switches
to using the CPython API, which allows you to create a correctly sized
tuple at the beginning and simply fill it in. This appears to offer
around a 10% boost when fetching rows from a table where the data is
already in memory.
Thanks Damien, Churchill!

See:
* https://github.com/pymssql/pymssql/pull/178

- MSSQLConnection: Add `with` (context manager) support (GH-171)

This adds `with` statement support for MSSQLConnection in the `_mssql`
module -- e.g.::

with mssqlconn() as conn:
conn.execute_query("SELECT version AS version")

We already have `with` statement support for the `pymssql` module.
See:

* https://github.com/pymssql/pymssql/pull/171

- Allow passing in binary data (GH-179)

Use the bytesarray type added in Python 2.6 to signify that this is
binary data and to quote it accordingly. Also modify the handling of
str/bytes types checking the first 2 characters for b'0x' and insert
that as binary data.
See:

* https://github.com/pymssql/pymssql/pull/179

- Add support for binding uuid.UUID instances to stored procedures input
params (GH-143)
Thanks, Ramiro Morales!

See:
* https://github.com/pymssql/pymssql/pull/143
* https://github.com/pymssql/pymssql/commit/1689c83878304f735eb38b1c63c31e210b028ea7

- The version number is now stored in one place, in pymssql_version.h
This makes it easier to update the version number and not forget any
places, like I did with pymssql 2.0.1

* See https://github.com/pymssql/pymssql/commit/fd317df65fa62691c2af377e4661defb721b2699

- Improved support for using py.test as test runner (GH-183)

* See: https://github.com/pymssql/pymssql/pull/183

- Improved PEP-8 and pylint compliance

Bug Fixes
---------

- GH-142 ("Change how ``*.pyx`` files are included in package") - this
should prevent pymssql.pyx and _mssql.pyx from getting copied into the
root of your virtualenv. Thanks, Arfrever!

* See: https://github.com/pymssql/pymssql/issues/142

- GH-145 ("Prevent error string growing with repeated failed connection
attempts.")

See:

* https://github.com/pymssql/pymssql/issues/145
* https://github.com/pymssql/pymssql/pull/146

- GH-151 ("err_handler: Don't clobber dberrstr with oserrstr")

* https://github.com/pymssql/pymssql/pull/151

- GH-152 ("_mssql.pyx: Zero init global last_msg_* vars")
See: https://github.com/pymssql/pymssql/pull/152

- GH-177 ("binary columns sometimes are processed as varchar")
Better mechanism for pymssql to detect that user is passing binary
data.

See: https://github.com/pymssql/pymssql/issues/177

- buffer overflow fix (GH-182)

* See: https://github.com/pymssql/pymssql/pull/181
* See: https://github.com/pymssql/pymssql/pull/182

- Return uniqueidentifer columns as uuid.UUID objects on Python 3


See `ChangeLog.old`_ for older history...

.. _Travis CI: https://travis-ci.org/pymssql/pymssql
.. _Cython: http://cython.org/
.. _ChangeLog.old: https://github.com/pymssql/pymssql/blob/master/ChangeLog.old