Setting primary_key=True on an non-integer field isn't yet supported

[jmb@…]

The admin interface appears to want to keep the primary_key numerical, and so breaks if you have set a field as primary_key=True.

Model:

class Airfield(meta.Model):
    fields = (
        meta.CharField('code', 'airfield code', maxlength=4, primary_key=True),
        meta.CharField('name', 'name', maxlength=50),
    )
    admin = meta.Admin(
        fields = (
            (None, {'fields': ('code', 'name')}),
        ),
    )
    def __repr__(self):
        return self.name

Result from trying to add an item through the admin interface:

There's been an error:

Traceback (most recent call last):

  File "/sw/lib/python2.3/site-packages/django/core/handlers/wsgi.py", line 190, in get_response
    return callback(request, **param_dict)

  File "/sw/lib/python2.3/site-packages/django/views/admin/main.py", line 769, in add_stage
    log.log_action(request.user.id, opts.get_content_type_id(), getattr(new_object, opts.pk.name), repr(new_object), log.ADDITION)

  File "/sw/lib/python2.3/site-packages/django/models/auth.py", line 293, in _module_log_action
    e.save()

  File "/sw/lib/python2.3/site-packages/django/core/meta.py", line 57, in _curried
    return args[0](*(args[1:]+moreargs), **dict(kwargs.items() + morekwargs.items()))

  File "/sw/lib/python2.3/site-packages/django/core/meta.py", line 748, in method_save
    (opts.db_table, ','.join(field_names), ','.join(placeholders)), db_values)

  File "/sw/lib/python2.3/site-packages/django/core/db/base.py", line 10, in execute
    result = self.cursor.execute(sql, params)

ProgrammingError: ERROR:  invalid input syntax for integer: "EGKR"

INSERT INTO auth_admin_log (action_time,user_id,content_type_id,object_id,object_repr,action_flag,change_message) VALUES ('2005-07-19 01:31:40',1,17,'EGKR','Redhill',1,'')

[Manuzhai <mail@…>]

Why this is currently not working: the model decides if an object is new by doing

not bool(getattr(self, opts.pk.name))

BUT for non-AutoField PK's, the PK will be filled in by the user, so it thinks the object isn't new when in fact it is, so it tries to update it instead of creating it. In order to fix this, some additional attribute is probably required that keeps track of whether the object is new or not.

[hugo <gb@…>]

This problem arises because the admin tries to log the change in the auth_admin_log. It references objects from there by an integer ID, but your model uses a non-integer primary key. The admin needs to be enhanced to handle non-integer primary keys for this to work (I have a similar problem in one of my play projects, too).

[hugo <gb@…>]

An alternative solution (as changing the object_id in the admin loggin would require a change to the database schema of the log) the admin logging could allow logging of "unlinked" events - if the key isn't an integer, just store the data with NULL as the key and don't link to the changed object. That way we can at least add objects via admin and get log notifications.

[boffbowsh@…]

If you change the field type yourself as a temporary fix, does stuff still break?

[Adrian Holovaty]

(In [455]) Slightly refactored metasystem -- changed Field pre_save() hooks to pre_save_add(), in preparation for some bigger changes. Refs #81.

[Adrian Holovaty]

(In [462]) Refactored the way save() works so that non-integer primary keys are now possible. custom_pk unit tests (from [458]) now pass. Refs #81.

[hugo <gb@…>]

saving does work now, only admin auth log still produces a traceback and viewing an object in the admin doesn't work if the primary key isn't an integer, due to the too restrictive urlpatterns (they use \d+ - maybe they should use \S+, instead)

[Adrian Holovaty]

(In [469]) Fixed #81 -- Admin now supports primary_key=True for non-integer fields. Note that you'll have to make a change to your database if you're using a previous Django installation and want to use non-integer primary key fields. See the BackwardsIncompatibleChanges wiki page for info.

[(none)]

Milestone Version 1.0 deleted