A very quick overview

Design your model

Write sample_pymodel.py:

#! /usr/bin/env python
from Modeling.PyModel import *

# Defaults
AString.defaults['width'] = 40

Entity.defaults['properties'] = [
  APrimaryKey('id', isClassProperty=0, isRequired=1, doc='PK')
]
##
_connDict = {'database': 'SampleDB', 'host': 'localhost',
             'user': 'postgres', 'password': ''}
model = Model('Sample',adaptorName='Postgresql', connDict=_connDict)
model.version='0.1'
model.entities = [
  Entity('Person',
         properties=[ AString('firstName'),
                      AString('lastName',isRequired=1)]  ),
  Entity('Address',
         properties=[  AString('street'),
                       AString('zipCode', width=10),
                       AString('town', isRequired=1) ],  ),
  ]
#---
model.associations=[
  Association('Address','Person',
              relations=['person','addresses'],
              delete=['nullify','deny'] ),
  ]

Verify the correctness of your model

shell> mdl_validate_model.py sample_pymodel.py

(note: use option -h on python scripts for details)

Generate the python code

shell> mdl_generate_python_code.py sample_pymodel.py

Note: python modules and classes can also be generated dynamically on the fly.
If you're interested in such a feature, you want to have a look at this patch for details.

Generate the corresponding database schema

Either get the coresponding sql statements:

shell>  mdl_generate_DB_schema.py -c -C sample_pymodel.py

CREATE TABLE PERSON (
  FIRST_NAME VARCHAR(40) , 
  LAST_NAME VARCHAR(40) NOT NULL, 
  ID INTEGER NOT NULL);
CREATE TABLE ADDRESS (
  TOWN VARCHAR(40) NOT NULL, 
  FK_PERSON INTEGER , 
  STREET VARCHAR(40) , 
  ID INTEGER NOT NULL, 
  ZIP_CODE VARCHAR(10) );
ALTER TABLE PERSON ADD PRIMARY KEY (ID);
ALTER TABLE ADDRESS ADD PRIMARY KEY (ID);
ALTER TABLE ADDRESS ADD CONSTRAINT person FOREIGN KEY (FK_PERSON) REFERENCES PERSON(ID) INITIALLY DEFERRED;
CREATE SEQUENCE PK_SEQ_PERSON START 1;
CREATE SEQUENCE PK_SEQ_ADDRESS START 1;

Or create the database directly:

shell> mdl_generate_DB_schema.py -C --admin-dsn="localhost:template1:postgres:" sample_pymodel.py

Use it!

>>> from Sample.Person import Person
>>> from Sample.Address import Address
>>> from Modeling.EditingContext import EditingContext
>>> ec=EditingContext()

>>> # create objects
... john=Person(firstName='John', lastName='Cleese')
>>> ec.insert(john)
>>> jeanne=Person(firstName='Jeanne', lastName='Cleese')
>>> ec.insert(jeanne)

>>> # create relationships
... a_john=Address(town='London')
>>> ec.insert(a_john)
>>> john.addToAddresses(a_john); a_john.setPerson(john)
>>>
>>> a_jeanne=Address(town='Paris')
>>> ec.insert(a_jeanne)
>>> jeanne.addToAddresses(a_jeanne); a_jeanne.setPerson(jeanne)

>>> # save changes
>>> ec.saveChanges()

>>> # fetch objects
... in_london=ec.fetch('Person', 'addresses.town ilike "*london*"')
>>> [(p.getLastName(), p.getFirstName()) for p in in_london]

Hosted by:

Sébastien Bigaret 2006-03-04