Duplicate key issue when loading back.json file PostgreSQL

Question

I have a PostgreSQL database that where I performed python manage.py dumpdata to backup the data into a json file. I created a new PostgreSQL database, performed a migrate, and everything worked like clockwork. When I tried to load the backup.json file with python manage.py loaddata backup.json it, gives me this error.

Could not load contenttypes.ContentType(pk=15): duplicate key value violates unique constraint "django_content_type_app_label_76bd3d3b_uniq"
DETAIL:  Key (app_label, model)=(navigation, navigation) already exists.

I checked phpPgAdmin, and there is a row for News. Is there a way to load the backup json file without including the content types, or better yet dump everything except for content types data ?

if you just exclude ContentTypes - you might hit another duplicate and another, and another. It needs wider approach change I think — Vao Tsun, Sep 26 '17 at 08:03
There are some differences between a postgres native `pg_restore` and django `loaddata`. This article clearly explains these differences and possible solutions - http://deephacks.com/articles/entry/django-backups-dumpdata-versus-sql-dump-postgresql-and-mysql/ But as @Vao Tsun advices, it would be better to find these constraint issues deep into your data. — Mahesh H Viraktamath, Sep 26 '17 at 11:14

score 24 · Answer 1 · answered Dec 06 '19 at 06:40

24

I was getting similar error:

django.db.utils.IntegrityError: Problem installing fixture '/home/knysys/ogmius/ogmius/db.json': Could not load contenttypes.ContentType(pk=2): duplicate key value violates unique constraint "django_content_type_app_label_model_76bd3d3b_uniq" DETAIL: Key (app_label, model)=(auth, user) already exists

After that, I found out that If you are restoring a fresh database from another database, You need to dumpdata like this:

./manage.py dumpdata --exclude auth.permission --exclude contenttypes > db.json

and then load fresh database like this:

./manage.py loaddata db.json

answered Dec 06 '19 at 06:40

ARKhan

1,724
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this works but now I can not log in – sutan Jun 07 '22 at 20:00
@sutan it seems that the loaddata command has overwrite your users table also. Maybe you have a user from where you have loaded your db.json. – ARKhan Jun 08 '22 at 18:32

score 4 · Answer 2 · answered Jan 25 '23 at 18:43

4

You can use the following command to load data:

python manage.py loaddata --exclude auth.permission --exclude contenttypes back.json

answered Jan 25 '23 at 18:43

Raskolnikov

315
1
2
7

Duplicate key issue when loading back.json file PostgreSQL

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