How can I activate the unaccent extension on an already existing model - django

Question

When I try to install the unaccent Postgres extension (through the postgresql-contrib package), everything works as per the below:
# psql -U postgres -W -h localhost
Password for user postgres:
psql (9.3.9)
SSL connection (cipher: DHE-RSA-AES256-GCM-SHA384, bits: 256)
Type "help" for help.
postgres=# CREATE EXTENSION unaccent;
CREATE EXTENSION
postgres=# SELECT unaccent('Hélène');
unaccent
----------
Helene
(1 row)
However, when I try to use with Django 1.8, I get following error:
ProgrammingError: function unaccent(character varying) does not exist
LINE 1: ...able" WHERE ("my_table"."live" = true AND UNACCENT("...
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
Using Postgresql 9.3 and Django 1.8.

Answer 1

A migration file needs to be manually made and applied.
First, create an empty migration:
./manage.py makemigrations myapp --empty
Then open the file and add UnaccentExtension to operations:
from django.contrib.postgres.operations import UnaccentExtension
class Migration(migrations.Migration):
dependencies = [
(<snip>)
]
operations = [
UnaccentExtension()
]
Now apply the migration using ./manage.py migrate.
If you'd get following error during that last step:
django.db.utils.ProgrammingError: permission denied to create extension "unaccent"
HINT: Must be superuser to create this extension.
... then temporarily allow superuser rights to your user by performing postgres# ALTER ROLE <user_name> SUPERUSER; and its NOSUPERUSER counterpart. pgAdminIII can do this, too.
Now enjoy the unaccent functionality using Django:
>>> Person.objects.filter(first_name__unaccent=u"Helène")
[<Person: Michels Hélène>]