This document summarizes the evolution of Django's model syntax from its early beginnings in 2004 to the present day trunk version. It shows the creation of database tables and models for a polls application. The model syntax progressed from raw SQL, to a custom Model class, to utilizing Django's built-in Model and fields, and later the introduction of the Meta inner class. It ends by showing how models are now registered with the admin using a separate admin.py file.

1. A brief history of
Django model syntax

2. r1000
January 2004

3. cms/apps/polls/dblayout.sql
BEGIN;
CREATE TABLE polls (
id serial PRIMARY KEY,
label varchar(20) NOT NULL, -- used by the template and possibly by the URL
release_date timestamp with time zone NOT NULL,
expire_date timestamp with time zone NOT NULL,
question varchar(255) NOT NULL
);
CREATE INDEX polls_label ON polls (label);
CREATE TABLE poll_choices (
id serial PRIMARY KEY,
polls_id integer REFERENCES polls(id),
choice varchar(255) NOT NULL,
votes integer NOT NULL DEFAULT 0
);
CREATE TABLE poll_logged_votes (
poll_id integer NOT NULL REFERENCES polls(id),
choice_id integer NOT NULL REFERENCES poll_choices(id),
ip_address inet NOT NULL,
vote_time timestamp with time zone NOT NULL,
PRIMARY KEY (poll_id, ip_address, vote_time)
);
CREATE TABLE polls_sites (
polls_id integer NOT NULL REFERENCES polls(id),
sites_id integer NOT NULL REFERENCES sites(id),
PRIMARY KEY (polls_id, sites_id)
);
COMMIT;

4. cms/apps/polls/polls.py
class PollDoesNotExist(ObjectDoesNotExist):
pass
class ChoiceDoesNotExist(ObjectDoesNotExist):
pass
# ...
class Poll:
def __init__(self, id, label, release_date, expire_date, question):
# ...
def save(self):
# ...
def get_choices(self):
# ...
# ...
def get_poll_by_id(poll_id):
# ...
def get_poll_by_label(label, year, month):
# ...
def get_poll_list(year=None, month=None):
# ...

5. r4000
August 2004

6. cms/datadescriptions/polls.py
class Poll(gen.DataDescription):
app_name = APP_NAME
app_label = APP_LABEL
module_name = 'polls'
object_name = 'Poll'
object_name_verbose = 'poll'
db_table = 'polls'
representation = ['return self.question']
fields = (
gen.AutoincrementField('id', 'ID', primary_key=True),
gen.SlugField('slug', 'slug', unique_for_month='pub_date'),
gen.CharacterField('question', 'question', maxlength=255),
gen.DatetimeField('pub_date', 'date published',
create_list_lookup_function=True, lookup=gen.DATEPART, create_next_previous=True),
gen.DatetimeField('expire_date', 'expiration date'),
gen.ManyToManyField('sites', 'sites', can_be_blank=True,
relationship=gen.ManyToManyRelation(core.Site, 'site_id')),
)
list_ordering_tuple = (('pub_date', gen.ORDER_ASCENDING),)
exceptions = (
('AlreadyVoted', None),
('PollClosed', None),
('InvalidVote', quot;An attempt to vote for a choice that isn't associated with the given pollquot;)
)
generate_admin = True
hierarchical_admin = (gen.BY_DATE, 'pub_date')
add_permission = ('add_poll', 'Can add polls')
change_permission = ('change_poll', 'Can change polls')
template_admin_form = 'polls_form'
admin_url = 'polls'
admin_field_conf = (
(None, {'classes': ('aligned',), 'fields': ('question', 'slug', 'pub_date', 'expire_date', 'sites')}),
)
extra_model_code_top = quot;from settings import POLL_VOTE_INTERVALquot;

7. cms/apps/polls/polls.py
# DO NOT EDIT THIS FILE MANUALLY. IT WAS GENERATED BY A PROGRAM.

8. r8825
June 2005
First public Django release

9. ellington/polls/models/polls.py
class Poll(meta.Model):
db_table = 'polls'
fields = (
meta.SlugField('slug', 'slug', unique_for_month='pub_date'),
meta.CharField('question', 'question', maxlength=255),
meta.DateTimeField('pub_date', 'date published'),
meta.DateTimeField('expire_date', 'expiration date'),
meta.ManyToManyField(core.Site),
meta.PositiveSmallIntegerField('choice_votes', 'choice votes', default=1,
help_text=quot;How many choices a person can vote for at once.quot;),
)
ordering = ('-pub_date',)
exceptions = ('AlreadyVoted', 'PollClosed', 'InvalidVote', 'TooFewChoices', 'TooManyChoices')
get_latest_by = 'pub_date'
admin = meta.Admin(
fields = (
(None, {'fields': ('question', 'slug', 'pub_date', 'expire_date', 'sites', 'choice_vo
),
list_display = ('question', 'pub_date', 'expire_date'),
list_filter = ('sites', 'pub_date'),
date_hierarchy = 'pub_date',
search_fields = ('question', 'slug'),
)

10. r9000
Django 0.91

11. ellington/polls/models/polls.py
class Poll(meta.Model):
slug = meta.SlugField(unique_for_month='pub_date')
question = meta.CharField(maxlength=255)
pub_date = meta.DateTimeField('date published')
expire_date = meta.DateTimeField('expiration date')
sites = meta.ManyToManyField(core.Site)
choice_votes = meta.PositiveSmallIntegerField(default=1)
class META:
db_table = 'polls'
ordering = ('-pub_date',)
exceptions = ('AlreadyVoted', 'PollClosed', 'InvalidVote', 'TooFewChoices', 'TooManyChoic
get_latest_by = 'pub_date'
admin = meta.Admin(
fields = (
(None, {'fields': ('question', 'slug', 'pub_date', 'expire_date', 'sites')}),
),
list_display = ('question', 'pub_date', 'expire_date'),
list_filter = ('sites', 'pub_date'),
date_hierarchy = 'pub_date',
search_fields = ('question', 'slug'),
)

12. r17000+
Trunk(ish)

13. ellington/polls/models.py
class Poll(models.Model):
slug = models.SlugField(unique_for_month='pub_date')
question = models.CharField(maxlength=255)
pub_date = models.DateTimeField('date published')
expire_date = models.DateTimeField('expiration date')
sites = models.ManyToManyField(core.Site)
choice_votes = models.PositiveSmallIntegerField(default=1)
class Meta:
ordering = ('-pub_date',)
get_latest_by = 'pub_date'
class Admin:
list_display = ('question', 'pub_date', 'expire_date')
list_filter = ('sites', 'pub_date')
date_hierarchy = 'pub_date'
search_fields = ('question', 'slug')
save_as = True

14. newforms-admin

15. ellington/polls/admin.py
from ellington.polls.models import Poll
class PollOptions:
list_display = ('question', 'pub_date', 'expire_date')
list_filter = ('sites', 'pub_date')
date_hierarchy = 'pub_date'
search_fields = ('question', 'slug')
save_as = True
admin.site.register(Poll, PollOptions)

16. Want to hack on
Ellington?
jacob@jacobian.org