Currently, one can specify the prefix length for an index
column using 'mysql_length' keyword argument when creating
an Index instance. But in case of composite indexes the
prefix length value is applied only to the last column.
Extend the existing API in way so that 'mysql_length' argument
value can be either:
- an integer specifying the same prefix length value
for each column of an index
- a (column_name --> integer value) mapping specifying
the prefix length value for each column of an index
separately
Fixes issue #2704.
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]
the joins as is, regardless of the dialect not supporting it. use_labels=True
indicates a higher level of automation and also can maintain the labels
between rewritten and not. use_labels=False indicates a manual use case.
: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]
Mike Bayer