django-db-views 0.0.1

Allow to create view migrations for view models. Migrations uses django engine. They can be reversed, (they remember previous view definition). View definition changes inside view models are detected automatically.Support almost all options as regular makemigrations command

django-db-views

How to use?

• add django_db_views to INSTALLED_APPS
• use makeviewmigrations command to create migrations for view models

How to create view in your database?

from django_db_views.db_view import DBView

class Balance(DBView):

    virtual_card = models.ForeignKey(
        VirtualCard, on_delete=models.DO_NOTHING, related_name='virtual_cards'
    )
    total_discount = models.DecimalField(max_digits=12, decimal_places=2)
    total_returns = models.DecimalField(max_digits=12, decimal_places=2)
    balance = models.DecimalField(max_digits=12, decimal_places=2)

    view_definition = """
        SELECT
            row_number() over () as id,  # Django requires column called id
            virtual_card.id as virtual_card_id,
            sum(...) as total_discount,
        ...
    """

    class Meta:
        managed = False
        db_table = 'virtual_card_balance'

How view migrations work?

• It's using Django code, view-migrations looks like regular migrations.
• It's relies on db_table names.
• makeviewmigrations command finds previous migration for view.
  • if there is no such migration, than script create new migration
  • if previous migration exists but no change in view_definition is detected nothing is done
  • if previous migration exists, then script will use previous view_definition for backward operation, and creates new migration.

Tested with live project based on Django 1.11.5