Django cannot create record with correct foreign key to CharField with spaces in middle - getting surrounded by single and double quotes like "'a a'"

Question

First of all - I understand that CharField is rather bad primary key, but it's unique in-game name, good 2 use as-is in many places, and may contain spacees. And IMHO the problem will repeat with non pkey field anyway

3 models - source, and two references. The first reference works perfectly in admin UI with the same code, the second - unworkanle during creating record

class PilotUsers(AbstractUser, PermissionsMixin):
    first_name = None
    last_name = None
    username = None

    ed_name = models.CharField(primary_key=True,max_length=60,null=False,blank=False,unique=True,verbose_name='Pilot name in Elite Dangerous', )
    squadron_tag = models.ForeignKey('Squadrons', verbose_name='Frontier squadron tag', on_delete=models.PROTECT, default='----')
    email = models.EmailField(unique=True)
    USERNAME_FIELD = 'ed_name'
    REQUIRED_FIELDS = ['email']
    objects = PilotUserManager()

    def __str__(self):
        return self.ed_name

    class Meta:
        app_label = 'common_pages'

This is working in admin UI - image below

class Cert(DetailsModel, AbstractCert):
    organizational_unit_name = models.ForeignKey('common_pages.PilotUsers', verbose_name='ED Pilot Name', on_delete=models.PROTECT)
    class Meta(AbstractCert.Meta):
        abstract = False
        swappable = swapper.swappable_setting("posts", "Cert")

This

class ActionFeed(models.Model):
    pkey = models.BigAutoField(primary_key=True)
    received = models.DateTimeField(verbose_name='Date-time')
    ed_name = models.ForeignKey('common_pages.PilotUsers', verbose_name='ED Pilot Name', on_delete=models.CASCADE)
#skipped
    raw_data = models.JSONField(verbose_name='Raw Data', null=False)

is unworkable during creating new record

print (f'Pilot = {pilot}')
record = ActionFeed(received= ts, ed_name=pilot, #skipped
                                           raw_data = entry)

The error is

Cannot assign "'Al L****]'": "ActionFeed.ed_name" must be a "PilotUsers" instance.

Attn - Single and double quote from each side of the name - debug printed w\o quotes at all

User is created by createsuperuser command and exactly valid - admin page login is OK. Compared names from Postgre amd input to the model byte by byte using ASCII 2 Hex conversion in case (of course w\o quotes) - exact. Something needed to be done for comparing data with spaces correctly, but no mind, what - plase, advice.

string, got from JSON - some masked by * Pilot = Al L*****U] BTW, was copy-pastin it for creating superuser — dAlexis
– dAlexis, Commented Jul 12 at 11:41

willeM_ Van Onsem · Accepted Answer · 2025-07-12 16:21:02Z

1

ed_name can not be assigned a string, or at least not directly. You can first fetch the PilotUsers object, and then assign it, like:

print(f'Pilot = {pilot}')
pilot_instance = get_object_or_404(PilotUsers, ed_name=pilot)
record = ActionFeed(received=ts, ed_name=pilot_instance, raw_data=entry)

or you can assign it through the underlying ed_name_id here, since it is a primary key:

print(f'Pilot = {pilot}')
record = ActionFeed(received=ts, ed_name_id=pilot_instance, raw_data=entry)

Therefore it also does not make much sense to name the field ed_name: it isn't an ed_name, but a PilotUsers object.

Note: Normally a Django model is given a singular name ^{[django-antipatterns]}, so PilotUser instead of ~~PilotUsers~~.

Note: It is probably not a good idea to work with a primary key over which user has control ^{[django-antipatterns]}. Django does not cover the case very well, and it can have all sorts of unwanted side-effects.

edited Jul 12 at 16:21

answered Jul 12 at 11:40

willeM_ Van Onsem

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1 Comment

dAlexis Jul 12 at 11:52

Thanks! Cannot upvote now, will, do later

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