Inline editing of foreign keys doesn't do pretty error handling.

[Nick Stenning]

When adding/editing foreign keys in the admin interface, any violation of NOT NULL or other schema specifications will throw a traceback rather than a pretty "this is what you did wrong" explanation when adding foreign keys manually.

There's been an error:

Traceback (most recent call last):

  File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/django/core/handlers/base.py", line 63, in get_response
    return callback(request, **param_dict)

  File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/django/views/admin/main.py", line 860, in change_stage
    new_object = manipulator.save(new_data)

  File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/django/core/meta.py", line 87, in _curried
    return args[0](*(args[1:]+moreargs), **dict(kwargs.items() + morekwargs.items()))

  File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/django/core/meta.py", line 1479, in manipulator_save
    new_rel_obj.save()

  File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/django/core/meta.py", line 87, in _curried
    return args[0](*(args[1:]+moreargs), **dict(kwargs.items() + morekwargs.items()))

  File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/django/core/meta.py", line 765, in method_save
    (opts.db_table, ','.join(field_names), ','.join(placeholders)), db_values)

  File "/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/django/core/db/base.py", line 10, in execute
    result = self.cursor.execute(sql, params)

IntegrityError: ERROR:  null value in column "votes" violates not-null constraint

INSERT INTO polls_choices (poll_id,choice,votes) VALUES ('1','This is making me hungry ;-)',NULL)

[Adrian Holovaty]

It's your responsibility to add blank=True to a field that has null=True if you want the admin to complain about blank values.

[marcink]

Could we change the tutorial to contain either the 'blank=True' parameter or a warning that this will happen? The stack trace does not look like it was there by design and spoils the first impression a bit.

[Gary Wilson]

There is now a note in the model-api docs that describes what blank=True does.