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deb-python-sqlalchemy-utils/docs/index.rst
2013-05-08 15:48:58 +03:00

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.. SQLAlchemy-Utils documentation master file, created by
sphinx-quickstart on Tue Feb 19 11:16:09 2013.
You can adapt this file completely to your liking, but it should at least
contain the root `toctree` directive.
SQLAlchemy-Utils
================
SQLAlchemy-Utils provides custom data types and various utility functions for SQLAlchemy.
Using automatic data coercion
-----------------------------
SQLAlchemy-Utils provides various new data types for SQLAlchemy and in order to gain full
advantage of these datatypes you should use coercion_listener. Setting up the listener is easy:
::
import sqlalchemy as sa
from sqlalchemy_utils import coercion_listener
sa.event.listen(sa.orm.mapper, 'mapper_configured', coercion_listener)
The listener automatically detects SQLAlchemy-Utils compatible data types and coerces all attributes
using these types to appropriate objects.
Example
::
from colour import Color
from sqlalchemy_utils import ColorType
class Document(Base):
__tablename__ = 'player'
id = db.Column(db.Integer, autoincrement=True)
name = db.Column(db.Unicode(50))
background_color = db.Column(ColorType)
document = Document()
document.background_color = 'F5F5F5'
document.background_color # Color object
session.commit()
ScalarListType
--------------
ScalarListType type provides convenient way for saving multiple scalar values in one
column. ScalarListType works like list on python side and saves the result as comma-separated list
in the database (custom separators can also be used).
Example ::
from sqlalchemy_utils import ScalarListType
class User(Base):
__tablename__ = 'user'
id = db.Column(db.Integer, autoincrement=True)
hobbies = db.Column(ScalarListType())
user = User()
user.hobbies = [u'football', u'ice_hockey']
session.commit()
You can easily set up integer lists too:
::
from sqlalchemy_utils import ScalarListType
class Player(Base):
__tablename__ = 'player'
id = db.Column(db.Integer, autoincrement=True)
points = db.Column(ScalarListType(int))
player = Player()
player.points = [11, 12, 8, 80]
session.commit()
ColorType
---------
ColorType provides a way for saving Color (from colour package) objects into database.
ColorType saves Color objects as strings on the way in and converts them back to objects when querying the database.
::
from colour import Color
from sqlalchemy_utils import ColorType
class Document(Base):
__tablename__ = 'player'
id = db.Column(db.Integer, autoincrement=True)
name = db.Column(db.Unicode(50))
background_color = db.Column(ColorType)
document = Document()
document.background_color = Color('#F5F5F5')
session.commit()
Querying the database returns Color objects:
::
document = session.query(Document).first()
document.background_color.hex
# '#f5f5f5'
For more information about colour package and Color object, see https://github.com/vaab/colour
NumberRangeType
---------------
NumberRangeType provides way for saving range of numbers into database.
Example ::
from sqlalchemy_utils import NumberRangeType, NumberRange
class Event(Base):
__tablename__ = 'user'
id = db.Column(db.Integer, autoincrement=True)
name = db.Column(db.Unicode(255))
estimated_number_of_persons = db.Column(NumberRangeType)
party = Event(name=u'party')
# we estimate the party to contain minium of 10 persons and at max
# 100 persons
party.estimated_number_of_persons = NumberRange(10, 100)
print party.estimated_number_of_persons
# '10-100'
NumberRange supports some arithmetic operators:
::
meeting = Event(name=u'meeting')
meeting.estimated_number_of_persons = NumberRange(20, 40)
total = (
meeting.estimated_number_of_persons +
party.estimated_number_of_persons
)
print total
# '30-140'
API Documentation
-----------------
.. module:: sqlalchemy_utils
.. autoclass:: InstrumentedList
:members:
.. autofunction:: sort_query
.. autofunction:: escape_like
.. include:: ../CHANGES.rst
License
-------
.. include:: ../LICENSE