Opened 18 years ago
Closed 16 years ago
#3774 closed (fixed)
Custom primary key allows to record a null or blank value
Reported by: | revil | Owned by: | nobody |
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Component: | Database layer (models, ORM) | Version: | dev |
Severity: | Keywords: | primary_key, custom primary key | |
Cc: | Triage Stage: | Design decision needed | |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
In a model I've used the following syntax for a custom primary key field:
name=models.SlugField('Name',maxlength=12,primary_key=True,
help_text='Descriptive name for the object')
But when I've entered in the admin interface and try to save an object without any value set in this field, django saves a record with blank name.
If I try to edit this object, the link to edit it is my main django project page.
Is this a bug or there is any explaination for this behavior?.
Change History (7)
comment:1 by , 18 years ago
Keywords: | primary_key custom added |
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Needs tests: | set |
follow-up: 3 comment:2 by , 18 years ago
Resolution: | → invalid |
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Status: | new → closed |
comment:3 by , 18 years ago
Resolution: | invalid |
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Status: | closed → reopened |
Replying to mtredinnick:
This is not a bug, since an empty string is a valid primary key value (just not a particularly useful one). Please post something to the django-users list if you need more help with this, but using "blank=False" will probably solve your problem.
I agree with you about that an empty string can be used as primary key, but in the django model reference you can read this:
primary_key
If True, this field is the primary key for the model.
If you don't specify primary_key=True for any fields in your model, Django will automatically add this field:
id = models.AutoField('ID', primary_key=True)
Thus, you don't need to set primary_key=True on any of your fields unless you want to override the default primary-key behavior.
primary_key=True implies blank=False, null=False and unique=True. Only one primary key is allowed on an object.
I believe that if setting primary_key to True, implies the previous mentioned statements, then would be not possible to create a blank string primary key.
If I'm wrong, please, explain me what's my misunderstanding.
Thanks for the response.
comment:4 by , 18 years ago
Needs tests: | unset |
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Triage Stage: | Unreviewed → Design decision needed |
revil is right: http://www.djangoproject.com/documentation/model_api/#primary-key. Either the behaviour of primary_key=True
needs to change, or the docs.
comment:5 by , 17 years ago
This is a serious problem. Is there anything we can do to at least trick the problem?
comment:6 by , 17 years ago
I'm also running into this problem.
What would happen, if we change:
paramsis_required = not self.blank and not self.primary_key and not rel
to
paramsis_required = not self.blank and not rel
here? --> http://code.djangoproject.com/browser/django/trunk/django/db/models/fields/__init__.py#L300
comment:7 by , 16 years ago
Resolution: | → fixed |
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Status: | reopened → closed |
This is not a bug, since an empty string is a valid primary key value (just not a particularly useful one). Please post something to the django-users list if you need more help with this, but using "blank=False" will probably solve your problem.