UniqueConstraints voided when using GenericTabularInline

[Mohamed Alnahhas]

Using Uniquecontraints, I get an error that the object already exist when I create a new object in the Skill_level admin page. However creating the same object through GenericTabularInline gives no errors and the creation is successful when it should not be. So basically Useconstraints is not working at all with GenericTabularInline

Generic field model:

class Skill_level(models.Model):
    level = models.IntegerField(default=1)
    user = models.ForeignKey(User, related_name="skill_level",on_delete=models.CASCADE)
    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
    object_id = models.PositiveBigIntegerField()
    content_object = GenericForeignKey("content_type", "object_id")

        
    class Meta:
        indexes = [
            models.Index(fields=["content_type", "object_id"]),
        ]
        constraints = [
            UniqueConstraint(fields=['user','content_type', 'object_id'], name='unique_object')
        ]

Generic relation model:

class Subject(models.Model):
    title = models.CharField(max_length=100)
    skill_level = GenericRelation(Skill_level, related_query_name="subject")

    def __str__(self):
        return f"{self.title}"

Admin.py:

class Skill_levelInline(GenericTabularInline):
    model = Skill_level
    extra = 0

class Skill_levelAdmin(admin.ModelAdmin):
    model = Skill_level
    fields = ['user', 'level', 'contnet_type', 'object_id', 'content_object']
    readonly_fields = ["content_object"]

class SubjectAdmin(admin.ModelAdmin):
    inlines = [Skill_levelInline]
    extra = 0

admin.site.register(Skill_level)
admin.site.register(Subject, SubjectAdmin)

[Simon Charette]

I didn't test it out but assume this is happening because GenericTabularInline's form is passing an exclude of either {'user','content_type', 'object_id'} the following statement confused me though

However creating the same object through GenericTabularInline gives no errors and the creation is successful when it should not be.

How is this possible, isn't the database crashing due a unique constraint violation?

Can you also reproduce the same issue by using unique_together instead of UniqueConstraint(fields=['user','content_type', 'object_id'], name='unique_object'). If you can then I'm not convinced this should be considered a release blocker.

[Mariusz Felisiak]

However creating the same object through GenericTabularInline gives no errors and the creation is successful when it should not be. So basically Useconstraints is not working at all with GenericTabularInline.

I cannot reproduce this issue, it crashes for me (as expected) with:

UNIQUE constraint failed: test_one_skill_level.user_id, test_one_skill_level.content_type_id, test_one_skill_level.object_id

If you're also getting IntegrityError than it's a duplicate of #13091.

[Mohamed Alnahhas]

Replying to Simon Charette:

I didn't test it out but assume this is happening because GenericTabularInline's form is passing an exclude of either {'user','content_type', 'object_id'} the following statement confused me though

However creating the same object through GenericTabularInline gives no errors and the creation is successful when it should not be.

How is this possible, isn't the database crashing due a unique constraint violation?

Can you also reproduce the same issue by using unique_together instead of UniqueConstraint(fields=['user','content_type', 'object_id'], name='unique_object'). If you can then I'm not convinced this should be considered a release blocker.

It is not crashing, the object is created successfully and I get the green success message I can even go to the Skill_level admin page and see the duplicate objects. Opening one of the objects and saving without any changes gives the usual Uniqueconstraints error message. I did try unique together and I was faced with the same exact behavior. I tagged the bug as release blocker because adding duplicate objects will cause critical errors in my application. I may end up converting this model to multiple foreign key models until this issue is fixed.

[Mohamed Alnahhas]

Replying to Mariusz Felisiak:

However creating the same object through GenericTabularInline gives no errors and the creation is successful when it should not be. So basically Useconstraints is not working at all with GenericTabularInline.

I cannot reproduce this issue, it crashes for me (as expected) with:

UNIQUE constraint failed: test_one_skill_level.user_id, test_one_skill_level.content_type_id, test_one_skill_level.object_id

If you're also getting IntegrityError than it's a duplicate of #13091.

I am not getting any errors at all, I get the green success message that the object was created successfully. I tried this on different models and got the same behavior. I dont know why were not able to reproduce this.

[Mariusz Felisiak]

Please attach a sample project. Maybe you're using a database that doesn't support unique constraints (e.g. MySQL < 8), or a 3rd-party database backend. It's difficult to say without a sample project.