Django and PostgreSQL

When working with Django and PostgreSQL it is typically best to use the psycopg[binary] package:

pip install psycopg[binary]

Migrating From Integer to Duration

If you need to migrate from an integer to a duration column you need to manually tell Postgres what unit of time to use - it won't assume that you mean seconds or minutes etc. Here is an example excerpt from a Gastronaut migration.

class Migration(migrations.Migration):

    dependencies = [
        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
        ('recipe_app', '0002_nurishifyprofile'),
    ]

    operations = [
        migrations.AlterField(
            model_name='nurishifyprofile',
            name='user',
            field=models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, related_name='profile', to=settings.AUTH_USER_MODEL),
        ),
        # workaround for migrating postgres
        migrations.RunSQL(
            "ALTER TABLE recipe_app_recipe ALTER COLUMN cooking_time TYPE interval USING cooking_time * interval '1 second'",
            reverse_sql=migrations.RunSQL.noop
        ),
        migrations.AlterField(
            model_name='recipe',
            name='cooking_time',
            field=models.DurationField(),
        ),