#30005: Example in documentation of transaction.atomic uses both decorator and
context manager
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Reporter: Peter Hull | Owner: Peter Hull
Type: Bug | Status: assigned
Component: Documentation | Version: 2.1
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
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Comment (by Simon Charette):
I don't think the example is wrong at all as the inner
`transaction.atomic` block creates a `SAVEPOINT` (because
`atomic(savepoint)` defaults to `True`) and thus the connection is usable
in the event of an `IntegrityError` because a rollback of the savepoint
would happen.
What the example is trying to demonstrate is that you can still nest
`transaction.atomic()` block safely if you wrap code expected to raise
database error appropriately and have queries within it's context be
atomic. In this case the `create_parent()` and `add_children()` calls will
be executed in the same transaction because of the function decorator.
Think of it this way, `atomic` would be completely impossible to use if
you couldn't nest calls this way given each calls to the database can
theoretically raise a database exception.
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Ticket URL: <https://code.djangoproject.com/ticket/30005#comment:4>
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