https://github.com/dnouri/kemi

kemi is an add-on for SQLAlchemy that aims to make defining relations with declarative easier for the most common cases.
https://github.com/dnouri/kemi

Last synced: 10 days ago
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kemi is an add-on for SQLAlchemy that aims to make defining relations with declarative easier for the most common cases.

• Host: GitHub
• URL: https://github.com/dnouri/kemi
• Owner: dnouri
• Created: 2012-03-26T17:09:45.000Z (almost 13 years ago)
• Default Branch: master
• Last Pushed: 2012-03-26T17:21:11.000Z (almost 13 years ago)
• Last Synced: 2024-10-28T13:27:14.452Z (about 2 months ago)
• Language: Python
• Homepage: http://pypi.python.org/pypi/kemi
• Size: 86.9 KB
• Stars: 4
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.rst

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kemi

====

kemi is an add-on for SQLAlchemy_ that aims to make defining relations

with declarative easier for the most common cases.

Consider this example from the SQLAlchemy docs::

  class Customer(Base):

      __tablename__ = 'customer'

      id = Column(Integer, primary_key=True)

      name = Column(String)

      billing_address_id = Column(Integer, ForeignKey("address.id"))

      shipping_address_id = Column(Integer, ForeignKey("address.id"))

      billing_address = relationship("Address",

                      primaryjoin="Address.id==Customer.billing_address_id")

      shipping_address = relationship("Address",

                      primaryjoin="Address.id==Customer.shipping_address_id")

Using kemi, this can be written as::

  class Customer(Base):

      name = Column(String)

      billing_address = relationship("Address")

      shipping_address = relationship("Address")

Things that kemi currently does:

* adds a ``__tablename__`` if none is explicitely set on the class

* adds an ``id`` column if no primary key column is present

* adds foreign key columns for relationships if no foreign key columns

  are present

* adds ``primaryjoins`` to relationships if they're not set

To use kemi, you need to use its DeclarativeMeta class when you make a

call to ``declarative_base``::

  from sqlalchemy.ext.declarative import declarative_base

  from kemi import DeclarativeMeta

  Base = declarative_base(metaclass=DeclarativeMeta)  

  class Customer(Base):

      name = Column(String)

      billing_address = relationship("Address")

      shipping_address = relationship("Address")

.. _SQLAlchemy: http://www.sqlalchemy.org/