Re: Migrating existing data into Django models

[Grigory Fateyev]

Hello tonemcd!
On Tue, 13 Dec 2005 10:27:30 - you wrote:

> 
> I found that any field with primary_key=True leads to a field name
> with _id appended. So your field will look like user_id_id in the
> database.
> 
> Try dropping the '_id' suffix perhaps?
> 
Nop,

Traceback (most recent call last):
  File "/usr/local/bin/django-admin.py", line 5, in ?
management.execute_from_command_line()
  File "/home/greg/www/django_src/django/core/management.py", line 958,
in execute_from_command_lineoutput = action_mapping[action](mod)
  File "/home/greg/www/django_src/django/core/management.py", line 70,
in get_sql_createrel_field = f.rel.get_related_field()
  File "/home/greg/www/django_src/django/core/meta/fields.py", line 846,
in get_related_fieldreturn self.to.get_field(self.field_name)
  File "/home/greg/www/django_src/django/core/meta/__init__.py", line
463, in get_fieldraise FieldDoesNotExist, "name=%s" % name
django.core.meta.FieldDoesNotExist: name=id

-- 
Всего наилучшего!
greg [at] anastasia [dot] ru Григорий.

Re: Migrating existing data into Django models

[tonemcd]

I found that any field with primary_key=True leads to a field name with
_id appended. So your field will look like user_id_id in the database.

Try dropping the '_id' suffix perhaps?

Re: Migrating existing data into Django models

[Grigory Fateyev]

Hello tonemcd!
On Thu, 08 Dec 2005 07:07:41 -0800 you wrote:

> 
> What does your auth model look like?
> 
class User(auth.User):
user_id = meta.CharField(maxlength=12, primary_key=True)
user_active = meta.BooleanField(default=True)
username = meta.CharField(maxlength=25)
user_password = meta.CharField(maxlength=32)
user_session_time = meta.IntegerField()
user_session_page = meta.IntegerField()
user_lastvisit = meta.DateTimeField(default=meta.LazyDate())
user_regdate = meta.DateTimeField(default=meta.LazyDate())
user_level = meta.CharField(maxlength=4)
user_posts = meta.IntegerField()
user_timezone = meta.FloatField(max_digits=5, decimal_places=2)
user_style = meta.CharField(maxlength=4)
[...]

-- 
Всего наилучшего!
greg [at] anastasia [dot] ru Григорий.

Re: Migrating existing data into Django models

[tonemcd]

What does your auth model look like?

Re: Migrating existing data into Django models

[Grigory Fateyev]

Hello Jacob Kaplan-Moss!
On Tue, 6 Dec 2005 14:16:06 -0600 you wrote:

>   class Story(meta.Model):
>   headline = meta.CharField(maxlength=100, primary_key=True)
>   body = meta.TextField()
> 
> you'll get::
> 
>   CREATE TABLE stories (
>   headline varchar(100) NOT NULL PRIMARY KEY,
>   body text NOT NULL
>   )
>   
> Clear?

I want to use it in my own auth model, but have error: 
> django-admin.py sql auth --settings=anastas.settings
BEGIN;
Traceback (most recent call last):
  File "/usr/local/bin/django-admin.py", line 5, in ?
management.execute_from_command_line()
  File "/home/greg/www/django_src/django/core/management.py", line 958,
in execute_from_command_lineoutput = action_mapping[action](mod)
  File "/home/greg/www/django_src/django/core/management.py", line 70,
in get_sql_createrel_field = f.rel.get_related_field()
  File "django/core/meta/fields.py", line 841, in get_related_field
return self.to.get_field(self.field_name)
  File "/home/greg/www/django_src/django/core/meta/__init__.py", line
463, in get_fieldraise FieldDoesNotExist, "name=%s" % name
django.core.meta.FieldDoesNotExist: name=id

It is possible to fix?

-- 
Всего наилучшего!
greg [at] anastasia [dot] ru Григорий.

Re: Migrating existing data into Django models

[tonemcd]

Hi Eric, I did a dig around and found emails from you on the Zope lists
(on my machine) going back to July 2001 - but I know you've been around
longer than that ;)

Yup, it's the primary_key field option I'm using - that seems to work
fine, my only problem now is that PostGres is rather less forgiving of
non-existent foreign keys than MySQL - well, it would be wouldn't it ;)

Re: Migrating existing data into Django models

[tonemcd]

Very clear Jacob! - a very clean example, thanks for that.

The second 'Story' model would need a user-created primary key I guess,
something the first model doesn't need.

I've had a dig around the legacy database documentation as well, which
was quite handy.

Now all I need to do is figure out a way around the PostGres integrity
errors I'm getting from the MySQL->PostGres migration and I think I'm
in business.

Re: Migrating existing data into Django models

[Kenneth Gonsalves]

On Wednesday 07 Dec 2005 1:51 am, Eric Walstad wrote:
> Nice to see a familiar "face" from the good old Zope days.
>  Welcome to the wonder world of Django.

i have also noticed one or two familiar faces from the good old 
Plone days ;-)

-- 
regards
kg

http://www.livejournal.com/users/lawgon
tally ho! http://avsap.org.in
ಇಂಡ್ಲಿನಕ್ಸ வாழ்க!

Re: Migrating existing data into Django models

[Eric Walstad]

On Tuesday 06 December 2005 12:01 pm, tonemcd wrote:
> The primary keys in the
> tables vary, but are mostly varchar.
[...]
> It seems though that Django uses ints for primary keys quite
> extensively, and I guess that will cause some problems with (say)
> creating new entries using the admin system.
>
> Does anyone have any pointers/hints/howtos etc on how to do this with a
> minimum of hassle?

Hi Tone,

Nice to see a familiar "face" from the good old Zope days.  Welcome to the 
wonder world of Django.

I've not used Django with non-integer-pk's yet, but I suspect what your after 
is the "primary_key" field option when defining your Django model.  Have a 
look here:


and search for "primary_key"

Also, there's an "Integrating with a legacy database" section of the docs 
here:


Good luck,

Eric.

Re: Migrating existing data into Django models

[Jacob Kaplan-Moss]

On Dec 6, 2005, at 2:01 PM, tonemcd wrote:

It seems though that Django uses ints for primary keys quite
extensively, and I guess that will cause some problems with (say)
creating new entries using the admin system.

Does anyone have any pointers/hints/howtos etc on how to do this  
with a

minimum of hassle?


Although Django uses integer primary keys by default, you can use any  
row as the primary key as long as you're explicit about it::


class Story(meta.Model):
headline = meta.CharField(maxlength=100)
body = meta.TextField()

would map to the following SQL::

CREATE TABLE stories (
id serial NOT NULL PRIMARY KEY, 
headline varchar(100) NOT NULL,
body text NOT NULL
)

(see the automatically added primary key), but if you do this::

class Story(meta.Model):
headline = meta.CharField(maxlength=100, primary_key=True)
body = meta.TextField()

you'll get::

CREATE TABLE stories (
headline varchar(100) NOT NULL PRIMARY KEY,
body text NOT NULL
)

Clear?

Also, if you're working on an existing schema, be sure to the legacy  
database documentation: http://www.djangoproject.com/documentation/ 
legacy_databases/


Jacob

Migrating existing data into Django models

[tonemcd]

Hi all,
I've been digging around Django for a while now as a possible
replacement for some Zope 2 sites we are running. The sites have large
MySQL (and in some cases PostGres) backends. The primary keys in the
tables vary, but are mostly varchar.

One thing I'm very keen to use the data model aspects of Django for is
to power admin sites and to separate the data from the presentation as
much as possible by using arbitrary methods as in
http://www.djangoproject.com/documentation/tutorial2/ (Zope has
something similar, called 'pluggable brains'). Our Zope systems have
become very cluttered, with data and logic intermixed quite
extensively, making maintenance and further development quite
difficult.

It seems though that Django uses ints for primary keys quite
extensively, and I guess that will cause some problems with (say)
creating new entries using the admin system.

Does anyone have any pointers/hints/howtos etc on how to do this with a
minimum of hassle?

Thanks a lot,
Tone