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
in callcounts specific to the "expiration" of objects, as in
the "auto expire" feature of :meth:`.Session.commit` and
for :meth:`.Session.expire_all`, as well as in the "cleanup" step
which occurs when object states are garbage collected.
fixes#3307
to start up listener collections; this pulls the overhead off of construction
and makes performance much like the descriptor version, while still allowing
slots. Fix up some profiles.
the python 3 merge, now does not expect percent signs (e.g.
as used as the modulus operator and others) to be doubled,
even when using the "pyformat" bound parameter format (this
change is not documented by Mysqlconnector). The dialect now
checks for py2k and for mysqlconnector less than version 2.0
when detecting if the modulus operator should be rendered as
``%%`` or ``%``.
- Unicode SQL is now passed for MySQLconnector version 2.0 and above;
for Py2k and MySQL < 2.0, strings are encoded. Note that mysqlconnector
as of 2.0.1 appears to have a bug with unicode DDL on py2k, so the tests here
are skipping until we observe it's fixed.
- take out profiling on mysqlconnector, callcounts vary too much with
its current development speed
"supports unicode statements" flag is now False, so that SQLAlchemy
will encode the *SQL string* (note: *not* the parameters)
to bytes before sending to the database. This seems to allow
all unicode-related tests to pass for mysql-connector, including those
that use non-ascii table/column names, as well as some tests for the
TEXT type using unicode under cursor.executemany().
- other mysql-connector fixes; latest version seems to do better on
function call counts
is currently being supported in addition to nose, and will likely
be preferred to nose going forward. The nose plugin system used
by SQLAlchemy has been split out so that it works under pytest as
well. There are no plans to drop support for nose at the moment
and we hope that the test suite itself can continue to remain as
agnostic of testing platform as possible. See the file
README.unittests.rst for updated information on running tests
with pytest.
The test plugin system has also been enhanced to support running
tests against mutiple database URLs at once, by specifying the ``--db``
and/or ``--dburi`` flags multiple times. This does not run the entire test
suite for each database, but instead allows test cases that are specific
to certain backends make use of that backend as the test is run.
When using pytest as the test runner, the system will also run
specific test suites multiple times, once for each database, particularly
those tests within the "dialect suite". The plan is that the enhanced
system will also be used by Alembic, and allow Alembic to run
migration operation tests against multiple backends in one run, including
third-party backends not included within Alembic itself.
Third party dialects and extensions are also encouraged to standardize
on SQLAlchemy's test suite as a basis; see the file README.dialects.rst
for background on building out from SQLAlchemy's test platform.
instead of relying upon various ``quote=True`` flags being passed around,
these flags are converted into rich string objects with quoting information
included at the point at which they are passed to common schema constructs
like :class:`.Table`, :class:`.Column`, etc. This solves the issue
of various methods that don't correctly honor the "quote" flag such
as :meth:`.Engine.has_table` and related methods. The :class:`.quoted_name`
object is a string subclass that can also be used explicitly if needed;
the object will hold onto the quoting preferences passed and will
also bypass the "name normalization" performed by dialects that
standardize on uppercase symbols, such as Oracle, Firebird and DB2.
The upshot is that the "uppercase" backends can now work with force-quoted
names, such as lowercase-quoted names and new reserved words.
[ticket:2812]
when loading mapped entities. The function overhead of applying
a per-object deferred callable to an instance at load time was
significantly higher than that of just loading the data from the row
(note that ``defer()`` is meant to reduce DB/network overhead, not
necessarily function call count); the function call overhead is now
less than that of loading data from the column in all cases. There
is also a reduction in the number of "lazy callable" objects created
per load from N (total deferred values in the result) to 1 (total
number of deferred cols).
[ticket:2778]
make sure that the DBAPI connection passed to the reset-on-return events/dialect hooks
is also a "fairy", so that dictionaries like "info" are available. [ticket:2770]
- rework the execution_options system so that the dialect is given the job of making
any immediate adjustments based on a set event. move the "isolation level" logic to use
this new system. Also work things out so that even engine-level execution options
can be used for things like isolation level; the dialect attaches a connect-event
handler in this case to handle the task.
- to support this new system as well as further extensibiltiy of execution options
add events engine_connect(), set_connection_execution_options(), set_engine_execution_options()
Mike Bayer