Go Live with Django & Heroku

I was following Justin Mitchels blog post about Going Live with Django and Heroku

I need to populate the database with a significant amount of data and I’ve been using

python manage.py loaddata --format json arch2json_all.json
Installed 221994 object(s) from 1 fixture(s)

In development with sqlite3 this works great.

Switch to my production branch push things up to Heroku

$ git push heroku master
$ heroku run python manage.py makemigrations
$ heroku run python manage.py migrate

Run into problems when I try to load the fixture.

$ heroku run bash
$ python manage.py loaddata --format json arch2json_all.json

django.db.utils.DataError: Problem installing fixture '/app/items/fixtures/arch2json_all.json': Could not load items.Monolithic(pk=None): value too long for type character varying(1024)

Looking in the usual locations I find a couple potential answers.

https://stackoverflow.com/questions/9036102/databaseerror-value-too-long-for-type-character-varying100

Could it be a SlugField without predefined length ?

class Monolithic(models.Model):
    slug = models.SlugField(max_length=512, default='page-slug', blank=True) 

Nope.

There’s only 1 field in the model that is 1024 or larger and that’s the msg field. But there none of the msg fields are even close to 1024 in size!

class Monolithic(models.Model):
    msg = models.CharField(max_length=1024, blank=True, null=True)
    slug = models.SlugField(max_length=512, default='page-slug', blank=True) 

So why does loaddata work on sqlite3 but not postgres?

$ heroku run python manage.py dbshell
=> \d items_monolithic
 msg                       | character varying(1024)  |           |          |

Change msg to a TextField

    msg = models.TextField(blank=True, null=True)

And still getting the error!

django.db.utils.DataError: Problem installing fixture '/app/items/fixtures/arch2json_all.json': Could not load items.Monolithic(pk=None): value too long for type character varying(1024)

Reset postgres?

$ heroku restart
$ heroku pg:reset DATABASE
 ▸    WARNING: Destructive action
 ▸    postgresql-acute-48401 will lose all of its data
 ▸
 ▸    To proceed, type testing or re-run this command with
 ▸    --confirm testing

> testing

No need to change the DATABASE

$ heroku run python manage.py makemigrations
$ heroku run python manage.py migrate
$ heroku run bash
$ python manage.py loaddata --format json arch2json_all.json
Installed 221994 object(s) from 1 fixture(s)

Why did I have to reset the postgres database?

Why didn’t makemigrations and migrate fix things?

Leave me a comment below.