Wasting Primary Key ID's

In case if you try to import a CSV file using ImportExportModelAdmin

say I have a Django modes named PRODUCTS as:

product_id (pk)     name (char)         size (char)   etc...
1                           milk                     500ml
2                           bread                  Large

admin.py looks like:

class ProductAdmin(ImportExportModelAdmin):
    resource_class = ProductResource

admin.site.register(Product, ProductAdmin)

resource.py that holds ProductResouces class look like:

class ProductResource(resources.ModelResource):
    class Meta:
        model = Product
        import_id_fields = ['product_id']
        skip_unchanged = True
        report_skipped = True
        use_transactions = True

and the issue is with uploading CSV file without product_id:

the CSV file looks like:

product_id (pk)     name (char)         size (char)   etc...
                            fresh milk              500ml

Note: Here I haven’t passed the product_id. So when I do import from my Django admin, it shows data as:

product_id (pk)     name (char)         size (char)   etc...
3                           fresh milk             500ml

Probably it get this primary key returned from database (MYSQL) and then shows confirm import button on chick of which the record I have is: 4 fresh milk 500ml

the id imported is 4 rather than 3.

I have IMPORT_EXPORT_USE_TRANSACTIONS = True in settings.py also have tried to make use_transactiosn = False in both settings.py and in resources.py and alternative combinations, still it wastes 1 primary key id in database whenever I don’t pass a primary key in my csv file

[andrewgy8]

Relevant bit of text here from #560 :

These only ever increase, and they’re exempt from the usual transaction rollback rules to permit multiple transactions to grab new IDs at the same time. This means that if a transaction rolls back, those IDs are “thrown away”; there’s no list of “free” IDs kept, just the current ID counter. Sequences are also usually incremented if the database shuts down uncleanly.

[bmihelac]

Please see https://github.com/django-import-export/django-import-export/issues/560#issuecomment-270673979