entities against the same base class joined to each other as well
would not track columns on the base table independently of each other if
the string of joins were more than two entities long. Also in 0.8.2.
[ticket:2759]
the :func:`.aliased` function. Previously, composite attributes
wouldn't work correctly in comparison operations when aliasing
was applied. Also in 0.8.2. [ticket:2755]
scalar values, for comparisons to None to also take into account
the association record itself being non-present, in addition to the
existing test for the scalar endpoint on the association record
being NULL. Previously, comparing ``Cls.scalar == None`` would return
records for which ``Cls.associated`` were present and
``Cls.associated.scalar`` is None, but not rows for which
``Cls.associated`` is non-present. More significantly, the
inverse operation ``Cls.scalar != None`` *would* return ``Cls``
rows for which ``Cls.associated`` was non-present.
Additionally, added a special use case where you
can call ``Cls.scalar.has()`` with no arguments,
when ``Cls.scalar`` is a column-based value - this returns whether or
not ``Cls.associated`` has any rows present, regardless of whether
or not ``Cls.associated.scalar`` is NULL or not.
[ticket:2751]
fetched when joining/joinedloading across a many-to-many
relationship to a single-table-inheriting
subclass with a specific discriminator value, due to "secondary"
rows that would come back. The "secondary" and right-side
tables are now inner joined inside of parenthesis for all
ORM joins on many-to-many relationships so that the left->right
join can accurately filtered.
[ticket:2369]
a CAST call that was added in 0.8.1 to help with driver issues,
which apparently is not compatible on 2000.
The CAST remains in place for SQL Server 2005 and greater.
[ticket:2747]
:class:`.ForeignKeyConstraint` will not render the ``DEFERRABLE`` keyword
on the MySQL dialect. For a long time we left this in place because
a non-deferrable foreign key would act very differently than a deferrable
one, but some environments just disable FKs on MySQL, so we'll be less
opinionated here. [ticket:2721]
foreign key paths to a table "B", to that table "B", would fail
to produce the "ambiguous join condition" error that would be
reported if you join table "A" directly to "B"; it would instead
produce a join condition with multiple criteria.
[ticket:2738]
evaluation invoked by :meth:`.Query.update` and :meth:`.Query.delete`
would hit upon unsupported ``True`` and ``False`` symbols
which now appear due to the usage of ``IS``.
[ticket:2737]
made the check for recursion overflow in self-referential
eager joining too loose, missing a particular circumstance
where a subclass had lazy="joined" or "subquery" configured
and the load was a "with_polymorphic" against the base.
[ticket:2481]
of :meth:`.Session.begin_nested` would fail to correctly
roll back the transaction when a flush error occurred, instead
raising its own exception while leaving the session still
pending a rollback. [ticket:2718]
that the "id" passed from the pickler is turned into a string
to prevent against bytes being parsed on Py3K, as well as that
``relationship()`` and ``orm.join()`` constructs are now properly
serialized. [ticket:2698] and some other observed issues.
mapped objects, such that if the reference to the object
were lost when the object was pickled, we don't
erroneously try to set up _sa_instance_state - fixes
a NoneType error.
to check for all the various "disconnect" messages within
the full exception hierarchy. Specifically the
"closed the connection unexpectedly" message has now been
seen in at least three different exception types.
[ticket:2712]
regards to the True/False constants. An expression like
``col.is_(True)`` will now render ``col IS true``
on the target platform, rather than converting the True/
False constant to an integer bound parameter.
This allows the ``is_()`` operator to work on MySQL when
given True/False constants.
[ticket:2682]
input types of sets, generators, etc. but only when a dimension
is specified for the ARRAY; otherwise, the dialect
needs to peek inside of "arr[0]" to guess how many
dimensions are in use. If this occurs with a non
list/tuple type, the error message is now informative
and directs to specify a dimension for the ARRAY.
[ticket:2681]
Mike Bayer