Now intermediate states in the database_backwards are cached, similar to
the executor's migrate() (or _migrate_all_backwards()). This makes the
migration run much faster (O(n) instead of O(n^2) over number of
database_operations).
The new signature enables better support for routing RunPython and
RunSQL operations, especially w.r.t. reusable and third-party apps.
This commit also takes advantage of the deprecation cycle for the old
signature to remove the backward incompatibility introduced in #22583;
RunPython and RunSQL won't call allow_migrate() when when the router
has the old signature.
Thanks Aymeric Augustin and Tim Graham for helping shape up the patch.
Refs 22583.
This reverts commit f36151ed16.
Adding kwargs to deconstructed objects does not achieve useful
forward-compatibility in general, since additional arguments are silently
dropped rather than having their intended effect. In fact, it can make the
failure more difficult to diagnose. Thanks Shai Berger for discussion.
This removes the concept of equality between operations to guarantee
compatilibity with Python 3.
Python 3 requires equality to result in identical object hashes. It's
impossible to implement a unique hash that preserves equality as
operations such as field creation depend on being able to accept
arbitrary dicts that cannot be hashed reliably.
Thanks Klaas van Schelven for the original patch in
13d613f800.
Avoided introducing a new regex-based SQL splitter in the migrations
framework, before we're bound by backwards compatibility.
Adapted this change to the legacy "initial SQL data" feature, even
though it's already deprecated, in order to facilitate the transition
to migrations.
sqlparse becomes mandatory for RunSQL on some databases (all but
PostgreSQL). There's no API to provide a single statement and tell
Django not to attempt splitting. Since we have a more robust splitting
implementation, that seems like a good tradeoff. It's easier to add a
new keyword argument later if necessary than to remove one.
Many people contributed to both tickets, thank you all, and especially
Claude for the review.
Refs #22401.
Added reversible property to RunPython so that migrations will not
refuse to reverse migrations including RunPython operations, so long as
reverse_code is set in the RunPython constructor. Included tests to
check the reversible property on RunPython and the similar RunSQL.
chillaranand
Anton Samarchyan
Claude Paroz
Markus Holtermann
Pankrat
Simon Charette
Amos Onn
Marten Kenbeek
Loic Bistuer
Carl Meyer
Patryk Zawadzki
Dave Hall
Andrew Godwin
Aymeric Augustin
Andrew Gorcester
Tim Graham
Alex Gaynor
Baptiste Mispelon