mirror of
https://github.com/kennethreitz/python-guide.git
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Andrew Janke
106 lines
3.3 KiB
ReStructuredText
106 lines
3.3 KiB
ReStructuredText
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#########
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Databases
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#########
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.. image:: /_static/photos/33907152464_a99fdcc8de_k_d.jpg
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******
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DB-API
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******
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The Python Database API (DB-API) defines a standard interface for Python
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database access modules. It's documented in :pep:`249`.
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Nearly all Python database modules such as `sqlite3`, `psycopg`, and
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`mysql-python` conform to this interface.
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Tutorials that explain how to work with modules that conform to this interface can be found
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`here <http://halfcooked.com/presentations/osdc2006/python_databases.html>`__ and
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`here <http://web.archive.org/web/20120815130844/http://www.amk.ca/python/writing/DB-API.html>`__.
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**********
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SQLAlchemy
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**********
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`SQLAlchemy <http://www.sqlalchemy.org/>`_ is a commonly used database toolkit.
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Unlike many database libraries it not only provides an ORM layer but also a
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generalized API for writing database-agnostic code without SQL.
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.. code-block:: console
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$ pip install sqlalchemy
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*******
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Records
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*******
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`Records <https://github.com/kennethreitz/records>`_ is minimalist SQL library,
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designed for sending raw SQL queries to various databases. Data can be used
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programmatically or exported to a number of useful data formats.
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.. code-block:: console
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$ pip install records
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Also included is a command-line tool for exporting SQL data.
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**********
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Django ORM
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**********
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The Django ORM is the interface used by `Django <http://www.djangoproject.com>`_
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to provide database access.
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It's based on the idea of
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`models <https://docs.djangoproject.com/en/dev/#the-model-layer>`_,
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an abstraction that makes it easier to manipulate data in Python.
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The basics:
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- Each model is a Python class that subclasses django.db.models.Model.
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- Each attribute of the model represents a database field.
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- Django gives you an automatically-generated database-access API; see
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`Making queries <https://docs.djangoproject.com/en/dev/topics/db/queries/>`__.
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******
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peewee
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******
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`peewee <http://docs.peewee-orm.com/en/latest/>`_ is another ORM with a focus
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on being lightweight with support for Python 2.6+ and 3.2+ which supports
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SQLite, MySQL, and PostgreSQL by default. The
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`model layer <https://peewee.readthedocs.io/en/latest/peewee/quickstart.html#model-definition>`_
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is similar to that of the Django ORM and it has
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`SQL-like methods <https://peewee.readthedocs.io/en/latest/peewee/quickstart.html#retrieving-data>`_
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to query data. While SQLite, MySQL, and PostgreSQL are supported out-of-the-box,
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there is a `collection of add-ons <https://peewee.readthedocs.io/en/latest/peewee/playhouse.html#playhouse>`_
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available.
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*******
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PonyORM
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*******
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`PonyORM <http://ponyorm.com/>`_ is an ORM that takes a different approach to
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querying the database. Instead of writing an SQL-like language or boolean
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expressions, Python's generator syntax is used. There's also a graphical
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schema editor that can generate PonyORM entities for you. It supports Python
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2.6+ and Python 3.3+ and can connect to SQLite, MySQL, PostgreSQL, and Oracle.
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*********
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SQLObject
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*********
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`SQLObject <http://www.sqlobject.org/>`_ is yet another ORM. It supports a wide
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variety of databases: common database systems like MySQL, PostgreSQL, and SQLite and
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more exotic systems like SAP DB, SyBase, and Microsoft SQL Server. It only supports Python 2
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from Python 2.6 upwards.
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.. There's no official information on this on their page; this information was gathered by looking at their source code.
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