https://github.com/linkdd/link.dbrequest

Database agnostic query system
https://github.com/linkdd/link.dbrequest

Last synced: about 1 year ago
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Database agnostic query system

• Host: GitHub
• URL: https://github.com/linkdd/link.dbrequest
• Owner: linkdd
• Created: 2016-06-03T14:17:04.000Z (almost 10 years ago)
• Default Branch: master
• Last Pushed: 2016-09-02T21:34:58.000Z (over 9 years ago)
• Last Synced: 2025-03-16T02:42:33.927Z (about 1 year ago)
• Language: Python
• Homepage:
• Size: 76.2 KB
• Stars: 0
• Watchers: 3
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.rst

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README

          
link.dbrequest

==============

**link.dbrequest** is a database agnostic query system.

See documentation_ for more informations.

.. _documentation: https://linkdbrequest.readthedocs.io

.. image:: https://img.shields.io/pypi/l/link.dbrequest.svg?style=flat-square

   :target: https://pypi.python.org/pypi/link.dbrequest/

   :alt: License

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   :target: https://pypi.python.org/pypi/link.dbrequest/

   :alt: Development Status

.. image:: https://img.shields.io/pypi/v/link.dbrequest.svg?style=flat-square

   :target: https://pypi.python.org/pypi/link.dbrequest/

   :alt: Latest release

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   :target: https://pypi.python.org/pypi/link.dbrequest/

   :alt: Supported Python versions

.. image:: https://img.shields.io/pypi/implementation/link.dbrequest.svg?style=flat-square

   :target: https://pypi.python.org/pypi/link.dbrequest/

   :alt: Supported Python implementations

.. image:: https://img.shields.io/pypi/wheel/link.dbrequest.svg?style=flat-square

   :target: https://pypi.python.org/pypi/link.dbrequest

   :alt: Download format

.. image:: https://travis-ci.org/linkdd/link.dbrequest.svg?branch=master&style=flat-square

   :target: https://travis-ci.org/linkdd/link.dbrequest

   :alt: Build status

.. image:: https://coveralls.io/repos/github/linkdd/link.dbrequest/badge.svg?style=flat-square

   :target: https://coveralls.io/r/linkdd/link.dbrequest

   :alt: Code test coverage

.. image:: https://img.shields.io/pypi/dm/link.dbrequest.svg?style=flat-square

   :target: https://pypi.python.org/pypi/link.dbrequest/

   :alt: Downloads

.. image:: https://landscape.io/github/linkdd/link.dbrequest/master/landscape.svg?style=flat-square

   :target: https://landscape.io/github/linkdd/link.dbrequest/master

   :alt: Code Health

Installation

------------

.. code-block:: text

   pip install link.dbrequest

Features

--------

 * database agnostic

 * lazy query resolving

 * cached queries

 * queries are unique

Examples

--------

Getting a backend:

.. code-block:: python

   from link.middleware.core import Middleware

   # Will open a QueryManager using a MongoDB backend

   manager = Middleware.get_middleware_by_uri('query+mongo://localhost:27107/mydatabase/mycollection')

   # Will open a QueryManager using a SQL backend

   manager = Middleware.get_middleware_by_uri('query+sql://localhost:5432/mydatabase/mytable')

Operations on the backend:

.. code-block:: python

   from link.dbrequest.expression import E, F

   from link.dbrequest.assignment import A

   from link.dbrequest.comparison import C

   query = manager.all()  # get an iterable over all elements

   manager.create(A('foo', 'bar'))  # put document {'foo': 'bar'} into database

   doc = manager.get(C('foo') != 'bar')  # get single element, or None

Operations on queries:

.. code-block:: python

   docs = list(query)  # iterate over query to execute the request

   docs = list(query)  # use cache when iterating again

   # create a new query from the first one

   q2 = query.filter(C('foo') == 'bar')

   assert query is not q2

   # exclude documents without a field named "bar"

   q3 = q2.exclude(~C('bar'))

   # filter documents "weight > 5" and "prop1 < prop2 * 5"

   q4 = q3.filter((C('weight') > 5) & (C('prop1') < (E('prop2') * 5)))

   # set "prop3 = prop1 + prop2" on q2 result

   docs = q2.update(A('prop3', E('prop1') + E('prop2')))

   # delete documents

   q3.delete()

Operations on documents:

.. code-block:: python

   # save/delete a single document

   doc.save()

   doc.delete()

Donating

--------

.. image:: https://liberapay.com/assets/widgets/donate.svg

   :target: https://liberapay.com/linkdd/donate

   :alt: Support via Liberapay