Decoupling models with cross-database relations
The snippet enables decoupling model classes, associated with a ForeignKey, for the purpose of separating them into two databases. Looking at the following example: class Reporter(models.Model): ... class Article(models.Model): reporter = models.ForeignKey(Reporter) We want to separate the `Reporter` and `Article` into two separate databases, but this won't work in Django because of the [cross model relations](http://docs.djangoproject.com/en/dev/topics/db/multi-db/#cross-database-relations). The solution is to use an ID field and not a `ForeignKey` one. This makes the access very uncomfortable. The above class will make this a bit less awkward. It doesn't support the [RelatedManager](http://docs.djangoproject.com/en/dev/ref/models/relations/#django.db.models.fields.related.RelatedManager), but it will support accessing the related field as you normally would. The article class will look like this (assuming the reporter model id field is an `IntegerField`): class Article(DecoupledModel): reporter_id = models.IntegerField() _linked_fields = { 'reporter': Reporter, } Once you have an article object, you can access the reporter as you normally would for both read and writing. For example: my_reporter = article1.reporter article2.reporter = my_reporter
- django
- model
- database