Django loaddata UNIQUE constraint failed

Question

I'm running python manage.py loaddata 'path/to/mydata.json' with an empty database (User and UserProfile tables are created but not populated), however, I'm getting the following error:

django.db.utils.IntegrityError: Problem installing fixture 'path/to/mydata.json': Could not load myapp.UserProfile(pk=1): UNIQUE constraint failed: myapp_userprofile.user_id

I checked (even after running this command) and the database is not populated at all. So how can it be giving an error that the pk is not unique?

If relevant, UserProfile just extends the default User model with a OneToOneField relation, as proposed here.

Here is what mydata.json contains:

[
    {
        "model": "auth.user",
        "pk": 1,
        "fields": {
            "password": "pbkdf2_sha256..",
            "last_login": "2016-10-22T15:19:46.926Z",
            "is_superuser": true,
            "username": "thesuperuser",
            "first_name": "",
            "last_name": "",
            "email": "a@a.co",
            "is_staff": true,
            "is_active": true,
            "date_joined": "2016-10-22T14:48:27.394Z",
            "groups": [],
            "user_permissions": []
        }
    },
    {
        "model": "auth.user",
        "pk": 2,
        "fields": {
            "password": "pbkdf2_sha256..",
            "last_login": null,
            "is_superuser": false,
            "username": "user1",
            "first_name": "User",
            "last_name": "One",
            "email": "",
            "is_staff": false,
            "is_active": true,
            "date_joined": "2016-10-22T15:20:32Z",
            "groups": [],
            "user_permissions": []
        }
    },
    {
        "model": "auth.user",
        "pk": 4,
        "fields": {
            "password": "pbkdf2_sha256..",
            "last_login": null,
            "is_superuser": false,
            "username": "user3",
            "first_name": "User",
            "last_name": "Three",
            "email": "",
            "is_staff": false,
            "is_active": true,
            "date_joined": "2016-10-22T15:21:09Z",
            "groups": [],
            "user_permissions": []
        }
    },
    {
        "model": "auth.user",
        "pk": 3,
        "fields": {
            "password": "pbkdf2_sha256..",
            "last_login": null,
            "is_superuser": false,
            "username": "user2",
            "first_name": "User",
            "last_name": "Two",
            "email": "",
            "is_staff": false,
            "is_active": true,
            "date_joined": "2016-10-22T15:21:03Z",
            "groups": [],
            "user_permissions": []
        }
    },
    {
        "model": "myapp.userprofile",
        "pk": 1,
        "fields": {
            "user": 1,
            "money": 100
        }
    },
    {
        "model": "myapp.userprofile",
        "pk": 2,
        "fields": {
            "user": 2,
            "money": 100
        }
    },
    {
        "model": "myapp.userprofile",
        "pk": 3,
        "fields": {
            "user": 3,
            "money": 100
        }
    },
    {
        "model": "myapp.userprofile",
        "pk": 4,
        "fields": {
            "user": 4,
            "money": 100
        }
    }
]

Thanks for any help,

score 13 · Answer 1 · answered Dec 06 '20 at 16:06

Exclude ContentType and Auth Permissions objects when creating a db dump.

python manage.py dumpdata --natural-foreign --natural-primary -e contenttypes -e auth.Permission --indent 2 > dump.json

After that you should be able to run the command without any issue

python manage.py loaddata dump.json

Credit to https://www.coderedcorp.com/blog/how-to-dump-your-django-database-and-load-it-into-/ for saving my day

score 10 · Answer 2 · answered Apr 24 '20 at 11:39

Today (24th, April, 2020) I had a similar problem with Django 2.2

My fixtures file was as simple as this:

[
{
    "model": "contenttypes.contenttype",
    "pk": 1,
    "fields": {
        "app_label": "admin",
        "model": "logentry"
    }
},
{
    "model": "contenttypes.contenttype",
    "pk": 2,
    "fields": {
        "app_label": "auth",
        "model": "permission"
    }
}]

When I ran ./manage.py loaddata initial_data.json, I got:

django.db.utils.IntegrityError: Problem installing fixture '/home/user/reponame/projectname/initial_data.json': Could not load contenttypes.ContentType(pk=2): UNIQUE constraint failed: django_content_type.app_label, django_content_type.model

What I did to make it work was just rename the pk to id for the contenttypes.contenttype model. After that, the migration worked as expected.

./manage.py loaddata initial_data.json 
Installed 2 object(s) from 1 fixture(s)

After the change, my initial_data.json file was:

[
{
    "model": "contenttypes.contenttype",
    "id": 1,
    "fields": {
        "app_label": "admin",
        "model": "logentry"
    }
},
{
    "model": "contenttypes.contenttype",
    "id": 2,
    "fields": {
        "app_label": "auth",
        "model": "permission"
    }
}]

It is worth mentioning that my original initial_dataj.json has many other models, but renaming pk to id only for the contenttypes.contenttype solved my problem.

Thank you, this works for me. I previously tried to change all pk to id, but that causes a ```django.contrib.contenttypes.models.DoesNotExist: ContentType matching query does not exist. KeyError: 'content_type' ``` — chia yongkang, Mar 20 '21 at 00:39
your solution is working perfectly. But what is the reason behind this? what are cons with this solution.? — khadim husen, Jun 27 '21 at 09:25
Hi @khadimhusen, I got to this point just by trial and error. — Ruben Alves, Jun 28 '21 at 13:13

score 7 · Answer 3 · answered Oct 30 '17 at 23:53

7

I had a similar problem. Inspired by this post:

https://github.com/yourlabs/django-cities-light/issues/89 (See 'how to fix it')

before running the loaddata command, I commented the receiver signal decorator before the 'saving function', and it worked.

answered Oct 30 '17 at 23:53

Matias David Lee

81
1
3

3

I cannot image a situation where you would want those post save hooks to run when doing a load of a db dump... – Andy T Oct 26 '18 at 11:00

score 1 · Answer 4 · answered Aug 12 '20 at 09:29

1

go the the json file and change evey single 'pk' to 'id' if you use vs code you can just select 1 and press cmd/ctrl + f2 as a shortcut

answered Aug 12 '20 at 09:29

Zeyad Shaban

604
1
6
18

1

does not work for me as it causes the content_type error – chia yongkang Mar 20 '21 at 00:34

score 0 · Answer 5 · answered Oct 05 '20 at 17:08

Had the same problem while exporting and importing a model with a ManyToMany relation. This was, because I manually speficied the ManyToMany through model while exporting, what caused an unique constraint error.

class MyModel(model.Model):
    
    groups = models.ManyToManyField(
        'myapp.mymodel',        
        
    )

You only need to execute dumpdata myapp.mymodel, not `dumpdata myapp.mymodel myapp.mymodel_groups"

Otherwise, your through model data is in the export twice, and causes a unique constraint error.

It`s a good question how this behaves, when you specify an explicit through model...i don't know and have no time to test :)

Django loaddata UNIQUE constraint failed

5 Answers5