Added a scenario for working with databases

Author: kisielk

docs/contents.rst.inc

@@ -68,6 +68,7 @@ different scenarios.
    scenarios/cli
    scenarios/gui
    scenarios/web
+   scenarios/db
    scenarios/admin
    scenarios/ci
    scenarios/speed

docs/scenarios/db.rst

@@ -0,0 +1,24 @@
+Databases
+=========
+
+DB-API
+------
+
+The Python Database API (DB-API) defines a standard interface for Python
+database access modules. It's documented in `PEP 249 <http://www.python.org/dev/peps/pep-0249/>`_.
+Nearly all Python database modules such as `sqlite3`, `psycopg` and
+`mysql-python` conform to this interface.
+
+
+
+SQLAlchemy
+----------
+
+`SQLAlchemy <http://www.sqlalchemy.org/>`_ is a commonly used database toolkit. Unlike many database libraries
+it not only provides an ORM layer but also a generalized API for writing
+database-agnostic code without SQL.
+
+::
+
+    pip install sqlalchemy
+