#12499 closed (wontfix)
Allow a model's Meta to specify a single multi-db alias
| Reported by: | Owned by: | nobody | |
|---|---|---|---|
| Component: | Database layer (models, ORM) | Version: | |
| Severity: | Keywords: | multi-db | |
| Cc: | crucialfelix@… | Triage Stage: | Unreviewed |
| Has patch: | no | Needs documentation: | no |
| Needs tests: | no | Patch needs improvement: | no |
| Easy pickings: | no | UI/UX: | no |
Description
Some, perhaps most models are clearly intended to work only with one connection or another in a multi-db project.
Currently you can specify:
objects = ModelManager().db_manager('legacy')
but I think the manager by default could look for:
class Meta:
connection = 'legacy'
and automatically bind to that connection
also I've run into a problem when running tests. the test runner causes each connection to create a test db which then creates all models on all connections.
if a connection does not support gis, or the model is not intended to be run on that connection ever, then the test db shouldn't create that table. thus I think that a model should be able to specify a single connection alias.
the above Meta setting would allow create_test_db to only create tables as needed for that connection.
This feature was implemented in an early draft of multi-db, and specifically removed. The database shouldn't be specified as a Meta property - consider the case of reusable apps. If your model defines Meta.connection (the original draft called it Meta.using), you can't share that model with any other Django user without forcing your particular database usage strategy.