directly or within lazy loads, didn't consider the mapper's "get clause"
as part of the cache key, causing bound parameter mismatches if the
clause got re-generated. This clause is cached by mappers
on the fly but in highly concurrent scenarios may be generated more
than once when first accessed.
fixes#3597
statement. This feature is available by passing the
:paramref:`~.sqlalchemy.sql.expression.update.preserve_parameter_order`
flag either to the core :class:`.Update` construct or alternatively
adding it to the :paramref:`.Query.update.update_args` dictionary at
the ORM-level, also passing the parameters themselves as a list of 2-tuples.
Thanks to Gorka Eguileor for implementation and tests.
adapted from pullreq github:200
versions 0.8.0 and 0.8.1, due 🎫`2714`. The case where
joined eager loading needs to join out over a subclass-bound
relationship when "with_polymorphic" were also used would fail
to join from the correct entity.
fixes#3593
limit/offset criteria that forces a subquery b. the relationship
uses "secondary" c. the primaryjoin of the relationship refers to
a column that is either not part of the primary key, or is a PK
col in a joined-inheritance subclass table that is under a different
attribute name than the parent table's primary key column d. the
query defers the columns that are present in the primaryjoin, typically
via not being included in load_only(); the necessary column(s) would
not be present in the subquery and produce invalid SQL.
fixes#3592
scope of a :meth:`.Session.flush` operation that's raising an
exception, as has been observed in some MySQL SAVEPOINT cases, prevents
the original database exception from being observed when it was
emitted during flush, but only on Py2K because Py2K does not support
exception chaining; on Py3K the originating exception is chained. As
a workaround, a warning is emitted in this specific case showing at
least the string message of the original database error before we
proceed to raise the rollback-originating exception.
fixes#2696
the many caveats and confusing effects of, the popular approach
of using contains_eager() to alter the natural result of a
related collection. I'm not a fan of this technique as it changes
the semantics of a relationship in such a way that the rest of the
ORM isn't aware of and it also can be undone very easily; hence the
section needs as much text for warnings as for describing the
technique itself. fixes#3563
to return ``datetime.timedelta`` in the same way as that of
:obj:`.types.Interval.python_type`, rather than raising
``NotImplementedError``.
fixes#3571
(cherry picked from commit 29d6f6e19b)
relationship flag; this flag *does* have an effect when the baked
lazy loader plugin has been invoked. clarify the intent of this
flag as an "opt out" but only has an effect when the baked system
is loaded anyway. fixes#3572
for UPDATE statements in the ORM (e.g. :ref:`feature_updatemany`)
would break on Postgresql and other RETURNING backends
when using server-side version generation
schemes, as the server side value is retrieved via RETURNING which
is not supported with executemany.
fixes#3556
:class:`.AssociationProxy` constructor, to suit the
:attr:`.AssociationProxy.info` accessor that was added in
🎫`2971`. This is possible because :class:`.AssociationProxy`
is constructed explicitly, unlike a hybrid which is constructed
implicitly via the decorator syntax.
fixes#3551
"auto increment" column has been changed, such that autoincrement
is no longer implicitly enabled for a :class:`.Table` that has a
composite primary key. In order to accommodate being able to enable
autoincrement for a composite PK member column while at the same time
maintaining SQLAlchemy's long standing behavior of enabling
implicit autoincrement for a single integer primary key, a third
state has been added to the :paramref:`.Column.autoincrement` parameter
``"auto"``, which is now the default. fixes#3216
- The MySQL dialect no longer generates an extra "KEY" directive when
generating CREATE TABLE DDL for a table using InnoDB with a
composite primary key with AUTO_INCREMENT on a column that isn't the
first column; to overcome InnoDB's limitation here, the PRIMARY KEY
constraint is now generated with the AUTO_INCREMENT column placed
first in the list of columns.
symbols with names quoted to force all-lower-case would not be
identified properly in reflection queries. The :class:`.quoted_name`
construct is now applied to incoming symbol names that detect as
forced into all-lower-case within the "name normalize" process.
fixes#3548
- repair the CREATE INDEX ddl for schemas
- update provisioning to include support for setting up ATTACH DATABASE up front
for the test_schema; enable "schemas" testing for SQLite
- changelog / migration notes for new SQLite schema support
- include the "schema" as the "remote_schema" when we reflect SQLite FKs
as part of 🎫`3424` to allow disabling of the MSSQL dialect's
attempts to create aliases for schema-qualified tables, now defaults
to False; the old behavior is now disabled unless explicitly turned on.
fixes#3434
which indicates to the ORM that a positive set of None should be
persisted as the value NULL, instead of omitting the column from
the INSERT statement. This feature is used both as part of the
implementation for 🎫`3514` as well as a standalone feature
available on any type. fixes#3250
- add new documentation section illustrating the "how to force null"
use case of #3250
- alter our change from #3514 so that the class-level flag is now
called "should_evaluate_none"; so that "evaluates_none" is now
a generative method.
to a :class:`.types.Enum` or :class:`.postgresql.ENUM` subtype
will now emit the expected "CREATE TYPE" and "DROP TYPE" DDL when
the type is used within a "CREATE TABLE" or "DROP TABLE".
fixes#2729
expression element which is late-evaluated at compile time. Previously,
the function was only a conversion function which would handle different
expression inputs by returning either a :class:`.Label` of a column-oriented
expression or a copy of a given :class:`.BindParameter` object,
which in particular prevented the operation from being logically
maintained when an ORM-level expression transformation would convert
a column to a bound parameter (e.g. for lazy loading).
fixes#3531
to use mapper.cascade_iterator() for this purpose as it was not really
designed for that use case. Add docs to cascade_iterator() pointing
to the recipe. fixes#3498
:meth:`.Session.bulk_save_objects` and related bulk methods have
been scaled back to the extent that this functionality is not
currently used, e.g. checks for column default values to be
fetched after an INSERT or UPDATE statement.
fixes#3526
column that had some kind of "fetch on update" value and was not
locally present in the given object would cause an AttributeError
within the operation.
fixes#3525
unambiguous tracking of all object lifecycle state transitions
in terms of the :class:`.Session` itself, e.g. pending,
transient, persistent, detached. The state of the object
within each event is also defined.
fixes#2677
- Added a new session lifecycle state :term:`deleted`. This new state
represents an object that has been deleted from the :term:`persistent`
state and will move to the :term:`detached` state once the transaction
is committed. This resolves the long-standing issue that objects
which were deleted existed in a gray area between persistent and
detached. The :attr:`.InstanceState.persistent` accessor will
**no longer** report on a deleted object as persistent; the
:attr:`.InstanceState.deleted` accessor will instead be True for
these objects, until they become detached.
- The :paramref:`.Session.weak_identity_map` parameter is deprecated.
See the new recipe at :ref:`session_referencing_behavior` for
an event-based approach to maintaining strong identity map behavior.
references #3517
insert statement, 🎫`3288`, where the column type for the
default-holding column would not be propagated to the compiled
statement in the case where the default was being used,
leading to bind-level type handlers not being invoked.
fixes#3520
Mike Bayer