diff options
Diffstat (limited to 'docs/topics')
| -rw-r--r-- | docs/topics/db/multi-db.txt | 6 | ||||
| -rw-r--r-- | docs/topics/migrations.txt | 20 |
2 files changed, 12 insertions, 14 deletions
diff --git a/docs/topics/db/multi-db.txt b/docs/topics/db/multi-db.txt index 7d4f2465c9..76df8610e3 100644 --- a/docs/topics/db/multi-db.txt +++ b/docs/topics/db/multi-db.txt @@ -150,7 +150,7 @@ A database Router is a class that provides up to four methods: used by foreign key and many to many operations to determine if a relation should be allowed between two objects. -.. method:: allow_migrate(db, model) +.. method:: allow_migrate(db, model, **hints) Determine if the ``model`` should have tables/indexes created in the database with alias ``db``. Return True if the model should be @@ -293,7 +293,7 @@ send queries for the ``auth`` app to ``auth_db``:: return True return None - def allow_migrate(self, db, model): + def allow_migrate(self, db, model, **hints): """ Make sure the auth app only appears in the 'auth_db' database. @@ -333,7 +333,7 @@ from:: return True return None - def allow_migrate(self, db, model): + def allow_migrate(self, db, model, **hints): """ All non-auth models end up in this pool. """ diff --git a/docs/topics/migrations.txt b/docs/topics/migrations.txt index 48021c724e..1220b4b41f 100644 --- a/docs/topics/migrations.txt +++ b/docs/topics/migrations.txt @@ -545,28 +545,26 @@ attribute:: migrations.RunPython(forwards), ] -You can also use your database router's ``allow_migrate()`` method, but keep in -mind that the imported router needs to stay around as long as it is referenced -inside a migration: +.. versionadded:: 1.8 + +You can also provide hints that will be passed to the :meth:`allow_migrate()` +method of database routers as ``**hints``: .. snippet:: :filename: myapp/dbrouters.py class MyRouter(object): - def allow_migrate(self, db, model): - return db == 'default' + def allow_migrate(self, db, model, **hints): + if 'target_db' in hints: + return db == hints['target_db'] + return True Then, to leverage this in your migrations, do the following:: from django.db import migrations - from myappname.dbrouters import MyRouter - def forwards(apps, schema_editor): - MyModel = apps.get_model("myappname", "MyModel") - if not MyRouter().allow_migrate(schema_editor.connection.alias, MyModel): - return # Your migration code goes here class Migration(migrations.Migration): @@ -576,7 +574,7 @@ Then, to leverage this in your migrations, do the following:: ] operations = [ - migrations.RunPython(forwards), + migrations.RunPython(forwards, hints={'target_db': 'default'}), ] More advanced migrations |