CODEWITHSUNDEEP
pythondjangopostgresqldjango-modelsdjango-import-export
Abdul Rehman
Abdul Rehman

Reputation: 5654

Django Import-Export Import Duplicate key value violates Error

I'm working on a project with Django 1.10, Python 3.6 and PostgreSQL as the database backend, in which I have a model called 'Article" and I need to import data from CSV files. I have imported my first CSV file successfully with the following fields: id, link & category It's ID fields starts from 1 to 1960 then in next file, I have started ID field from 1961 to onward but it shows the following error:

Line number: 1961 - duplicate key value violates unique constraint "article_article_pkey" DETAIL: Key (id)=(1961) already exists.

Even when i see my Article model in Django admin it shows IDs from 1- 1960

Here's my models.py:

class Article(models.Model):
   id = models.AutoField(primary_key=True)
   link = models.URLField(max_length=255)
   category = models.CharField(max_length=255, choices=Categories)

Here's admin.py

@admin.register(Article)
    class ArticleAdmin(ImportExportModelAdmin):
    resource_class = views.ArticleResource
    readonly_fields = ('id',)

Upvotes: 4

Views: 2586

Answers (3)

Électron libre
Électron libre

Reputation: 11

i often run a for loop. This also updates my auto datetime fields:

import Article
for i in range(1, your_last_id + 1):
    item = Article.objects.get(id=i)
    item.save()

your_last_id may be SELECT MAX(id)

Upvotes: 1

Chris
Chris

Reputation: 6382

I had this issue, because I'd specified a custom import_id_fields field but hadn't excluded the id field.

I had specified:

    import_id_fields = ('code',)
    skip_unchanged = True
    report_skipped = True

But I needed:

    import_id_fields = ('code',)
    skip_unchanged = True
    report_skipped = True
    exclude = ('id',)

Bit of a noob error but this might save someone a google.

Ref: https://github.com/django-import-export/django-import-export/issues/273

Upvotes: 2

Abdul Rehman
Abdul Rehman

Reputation: 5654

I have triggered that what's the issue : Actually, the problem is PostgreSQL primary key sequential which is not synced with table rows. That's why, when I insert a new row I get a duplicate key error because the sequence implied in the serial datatype returns a number that already exists.

To solve this issue we have to reset the ID sequential for PostgreSQL, Here's the step by step guide:

  1. Log onto the DB shell and connect to your database
  2. First, check maximum value for id column of your table as SELECT MAX(id) FROM your_table;
  3. Then, check what's going to be the next value for ID as : SELECT nextval('your_table_id_seq');
  4. If nextval is the next number of Max value then it's right. e.g MAX=10 & nextval=11

  5. Otherwise reset the id_seq for your table as:

    BEGIN;

    -- protect against concurrent inserts while you update the counter

    LOCK TABLE your_table IN EXCLUSIVE MODE;

    -- Update the sequence

    SELECT setval('your_table_id_seq', COALESCE((SELECT MAX(id)+1 FROM your_table), 1), false);

    COMMIT;

Upvotes: 2

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