<metaname="description" content="Full Stack Python shows how an entire Python web application is built and deployed. Each section of the guide explains a different key concept, from the server through the Python WSGI web framework to the front end JavaScript.">
<p>A database is an abstraction on top of an operating system's file system to
ease creating, reading, updating, and deleting persistent data. The
database storage abstraction most commonly used in Python web development is
sets of relational tables. Alternative storage abstractions are explained in
the <aclass="reference external" href="../no-sql-datastore.html">NoSQL</a> section of this guide.</p>
<p>Relational databases store all data in a series of tables. Interconnections
between the tables are specified as <em>foreign keys</em>.</p>
<p>Databases storage implementations vary in complexity. SQLite, a database
included with Python, creates a single file for all data per database.
Other databases such as Oracle, PostgreSQL, and MySQL have more complicated
persistence schemes while offering additional advanced features that are
useful for web application data storage.</p>
<p><aclass="reference external" href="http://www.postgresql.org/">PostgreSQL</a> and
<aclass="reference external" href="http://www.mysql.com/">MySQL</a> are two of the most common open source
databases for storing Python web application data.</p>
<p><aclass="reference external" href="http://www.sqlite.org/">SQLite</a> is a database that is stored in a single
file on disk. SQLite is built into Python but is only built for access
by a single connection at a time. Therefore is highly recommended to not
<aclass="reference external" href="https://docs.djangoproject.com/en/dev/ref/databases/#database-is-locked-errors">run a production web application with SQLite</a>.</p>