Connect to SMS Database
=======================

Under the hood, Rattail uses `pyodbc <http://code.google.com/p/pyodbc/>`_ to
connect to the SMS database.  Therefore in addition to editing rattail.conf,
you must create a `Data Source Name
<http://en.wikipedia.org/wiki/Data_Source_Name>`_ (DSN).

How you go about creating a DSN will vary depending on which operating system
you're using.  I'll only document the Windows method here, but rest assured
that Linux can talk to SMS as well.  (Some day that also will be documented. ;)

Create a DSN
------------

In Windows, you can (Start ->) run the command ``odbcad32`` to be shown the
ODBC Data Source Administrator.  Go to the System DSN tab and click Add, then
choose SQL Server for the driver.

Provide a name for the data source, and choose the server to which you wish to
connect.  Configure the authentication etc. to your liking but make sure you do
choose a default database for the data source.  You will set this to your SMS
database of course.

Configure Rattail
-----------------

Edit your rattail.conf file so it includes something like the following::

   [rattail]
   init = ['rattail.sw.locsms']

   [rattail.sw.locsms]
   sqlalchemy.url = mssql://MJ001901-SMS

The "MJ001901-SMS" in the above is the name of the data source I created in the
previous step.  SQLAlchemy's `engine_from_config()
<http://www.sqlalchemy.org/docs/core/engines.html#sqlalchemy.engine_from_config>`_
is used to create the engine.

Talk to SMS
-----------

Now the fun part::

   C:\tmp>rattail shell
   Rattail v0.2a2 launching Python shell...

   conf file(s): [
       'C:\envs\rattail.mamajeans\app\rattail.conf' ]

   init()ed: [
       'rattail',
       'rattail.sw.locsms' ]

   >>> locsms.__version__
   '0.2a1'
   >>> from rattail.sw.locsms import *
   >>> s = Session()
   >>> s.query(Product).count()
   29857
   >>> p = s.query(Product).get('0007430500132')
   >>> p
   <Product: 0007430500132>
   >>> p.F29
   'Apple Cidr Vingr'
   >>> p.subdepartment
   <Subdepartment: 600 Grocery: (catch-all)>
   >>> p.price
   <Price: 0007430500132: 5.6000/1.0>
   >>> p.price.F30
   Decimal('5.6000')
   >>>