gem-hunter

Django Postgres composite types

Usage

pip install django-postgres-composite-types

INSTALLED_APPS = [
    # ... Other apps
    'postgres_composite_types',
]

from django.db import models
from postgres_composite_types import CompositeType

class Address(CompositeType):
    """An address."""

    address_1 = models.CharField(max_length=255)
    address_2 = models.CharField(max_length=255)

    suburb = models.CharField(max_length=50)
    state = models.CharField(max_length=50)

    postcode = models.CharField(max_length=10)
    country = models.CharField(max_length=50)

    class Meta:
        db_type = 'x_address'  # Required


class Person(models.Model):
    """A person."""

    address = Address.Field()

import address
from django.db import migrations


class Migration(migrations.Migration):

    operations = [
        # Registers the type
        address.Address.Operation(),
        migrations.AddField(
            model_name='person',
            name='address',
            field=address.Address.Field(blank=True, null=True),
        ),
    ]

Examples

class Card(CompositeType):
    """A playing card."""

    suit = models.CharField(max_length=1)
    rank = models.CharField(max_length=2)

    class Meta:
        db_type = 'card'


class Hand(models.Model):
    """A hand of cards."""
    cards = ArrayField(base_field=Card.Field())

class Point(CompositeType):
    """A point on the cartesian plane."""

    x = models.IntegerField()
    y = models.IntegerField()

    class Meta:
        db_type = 'x_point'  # Postgres already has a point type


class Box(CompositeType):
    """An axis-aligned box on the cartesian plane."""
    class Meta:
        db_type = 'x_box'  # Postgres already has a box type

    top_left = Point.Field()
    bottom_right = Point.Field()

Gotchas and Caveats

operations = [
    migrations.RunSQL([
        "ALTER TYPE x_address DROP ATTRIBUTE country",
        "ALTER TYPE x_address ADD ATTRIBUTE country integer",
    ], [
        "ALTER TYPE x_address DROP ATTRIBUTE country",
        "ALTER TYPE x_address ADD ATTRIBUTE country varchar(50)",
    ]),
]

Running Tests

pip install tox
tox

tox -e py311-dj41

Authors

License