Squashed commit of the following:
commit 63ddb271a44df389b2c302e421fc17b7f0529755
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date: Sun Sep 29 22:51:00 2013 +0200
Clarified interactions between atomic and exceptions.
commit 2899ec299228217c876ba3aa4024e523a41c8504
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date: Sun Sep 22 22:45:32 2013 +0200
Fixed TransactionManagementError in tests.
Previous commit introduced an additional check to prevent running
queries in transactions that will be rolled back, which triggered a few
failures in the tests. In practice using transaction.atomic instead of
the low-level savepoint APIs was enough to fix the problems.
commit 4a639b059ea80aeb78f7f160a7d4b9f609b9c238
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date: Tue Sep 24 22:24:17 2013 +0200
Allowed nesting constraint_checks_disabled inside atomic.
Since MySQL handles transactions loosely, this isn't a problem.
commit 2a4ab1cb6e83391ff7e25d08479e230ca564bfef
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date: Sat Sep 21 18:43:12 2013 +0200
Prevented running queries in transactions that will be rolled back.
This avoids a counter-intuitive behavior in an edge case on databases
with non-atomic transaction semantics.
It prevents using savepoint_rollback() inside an atomic block without
calling set_rollback(False) first, which is backwards-incompatible in
tests.
Refs #21134.
commit 8e3db393853c7ac64a445b66e57f3620a3fde7b0
Author: Aymeric Augustin <aymeric.augustin@m4x.org>
Date: Sun Sep 22 22:14:17 2013 +0200
Replaced manual savepoints by atomic blocks.
This ensures the rollback flag is handled consistently in internal APIs.
Add support for Oracle, fix an issue with the repr of RawQuerySet,
add tests and documentations. Also added a 'supports_paramstyle_pyformat'
database feature, True by default, False for SQLite.
Thanks Donald Stufft for review of documentation.
This is useful:
- to force a rollback on the exit of an atomic block without having to
raise and catch an exception;
- to prevent a rollback after handling an exception manually.
This allows using flush on a subset of the tables without having to
manually cascade to all tables with foreign keys to the tables being
truncated, when they're known to be empty.
On databases where truncate is implemented with DELETE FROM, this
doesn't make a difference. The cascade is allowed, not mandatory.
Previously, depending on the database backend or the cursor type,
you'd need to double the percent signs in the query before passing
it to cursor.execute. Now cursor.execute consistently need percent
doubling whenever params argument is not None (placeholder substitution
will happen).
Thanks Thomas Güttler for the report and Walter Doekes for his work
on the patch.
Thanks Anssi for haggling until I implemented this.
This change alleviates the need for atomic_if_autocommit. When
autocommit is disabled for a database, atomic will simply create and
release savepoints, and not commit anything. This honors the contract of
not doing any transaction management.
This change also makes the hack to allow using atomic within the legacy
transaction management redundant.
None of the above will work with SQLite, because of a flaw in the design
of the sqlite3 library. This is a known limitation that cannot be lifted
without unacceptable side effects eg. triggering arbitrary commits.
Replaced them with per-database options, for proper multi-db support.
Also toned down the recommendation to tie transactions to HTTP requests.
Thanks Jeremy for sharing his experience.
Since "unless managed" now means "if database-level autocommit",
committing or rolling back doesn't have any effect.
Restored transactional integrity in a few places that relied on
automatically-started transactions with a transitory API.
Claude Paroz
Aymeric Augustin
Michael Manfre
Anssi Kääriäinen
Tim Graham
Gregor MacGregor
Andrew Godwin
Eric Boersma
Simon Charette
Alex Gaynor
Shai Berger
Erik Romijn