source/projects/anosql/doc/index.rst

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.. anosql documentation master file, created by
sphinx-quickstart on Mon Jul 25 09:16:20 2016.
You can adapt this file completely to your liking, but it should at least
contain the root `toctree` directive.
Welcome to anosql's documentation!
==================================
.. image:: https://badge.fury.io/py/anosql.svg
:target: https://badge.fury.io/py/anosql
:alt: pypi package version
.. image:: http://readthedocs.org/projects/anosql/badge/?version=latest
:target: http://anosql.readthedocs.io/en/latest/?badge=latest
:alt: Documentation status
.. image:: https://travis-ci.org/honza/anosql.svg?branch=master
:target: https://travis-ci.org/honza/anosql
:alt: Travis build status
A Python library for using SQL
Inspired by the excellent `Yesql`_ library by Kris Jenkins. In my mother
tongue, *ano* means *yes*.
If you are on python3.6+ or need ``anosql`` to work with ``asyncio`` based database drivers, see the related project `aiosql <https://github.com/nackjicholson/aiosql>`_.
Installation
------------
::
$ pip install anosql
Usage
-----
Basics
******
Given a ``queries.sql`` file:
.. code-block:: sql
-- name: get-all-greetings
-- Get all the greetings in the database
SELECT * FROM greetings;
We can issue SQL queries, like so:
.. code-block:: python
import anosql
import psycopg2
import sqlite3
# PostgreSQL
conn = psycopg2.connect('...')
queries = anosql.from_path('queries.sql', 'psycopg2')
# Or, Sqlite3...
conn = sqlite3.connect('cool.db')
queries = anosql.from_path('queries.sql', 'sqlite3')
queries.get_all_greetings(conn)
# => [(1, 'Hi')]
queries.get_all_greetings.__doc__
# => Get all the greetings in the database
queries.get_all_greetings.sql
# => SELECT * FROM greetings;
queries.available_queries
# => ['get_all_greetings']
Parameters
**********
Often, you want to change parts of the query dynamically, particularly values in the ``WHERE`` clause.
You can use parameters to do this:
.. code-block:: sql
-- name: get-greetings-for-language
-- Get all the greetings in the database for a given language
SELECT *
FROM greetings
WHERE lang = %s;
And they become positional parameters:
.. code-block:: python
visitor_language = "en"
queries.get_all_greetings_for_language(conn, visitor_language)
Named Parameters
****************
To make queries with many parameters more understandable and maintainable, you can give the parameters names:
.. code-block:: sql
-- name: get-greetings-for-language
-- Get all the greetings in the database for given language and length
SELECT *
FROM greetings
WHERE lang = :lang
AND len(greeting) <= :length_limit;
If you were writing a Postgresql query, you could also format the parameters as ``%s(lang)`` and ``%s(length_limit)``.
Then, call your queries like you would any Python function with named parameters:
.. code-block:: python
visitor_language = "en"
greetings_for_texting = queries.get_all_greetings(conn, lang=visitor_language, length_limit=140)
Contents
--------
.. toctree::
:maxdepth: 2
Getting Started <getting_started>
Defining Queries <defining_queries>
Extending anosql <extending>
Upgrading <upgrading>
API <source/modules>
License
-------
BSD, short and sweet
.. _Yesql: https://github.com/krisajenkins/yesql/