concurrent ability to return connections from the pool means that the
"first_connect" event is now no longer synchronized either, thus leading
to dialect mis-configurations under even minimal concurrency situations.
SQLite allows column types that aren't technically understood in sqlite
by using 'data affinity', which is an algorithm for converting column
types in to some sort of useful type that can be stored and retrieved
from the db. Unfortunatly, this breaks reflection since we (previously)
expected a sqlite db to reflect column types that we permit in the
`ischema_names` for that dialect.
This patch changes the logic for 'unknown' column types during
reflection to instead run through SQLite's data affinity algorithm, and
assigns appropriate types from that.
It also expands the matching for column type to include column types
with spaces (strongly discouraged but allowed by sqlite) and also
completely empty column types (in which case the NullType is assigned,
which sqlite will treat as a Blob - or rather, Blob is treated as
NullType). These changes mean that SQLite will never raise an error for
an unknown type during reflection - there will always be some 'useful'
type returned, which follows the spirit of SQLite (accomodation before
sanity!).
applied to :class:`.Constraint` and :class:`.Index` objects. Based
on a recipe in the wiki, the new feature uses schema-events to set up
names as various schema objects are associated with each other. The
events then expose a configuration system through a new argument
:paramref:`.MetaData.naming_convention`. This system allows production
of both simple and custom naming schemes for constraints and indexes
on a per-:class:`.MetaData` basis. [ticket:2923]
commit 7e65e52c086652de3dd3303c723f98f09af54db8
Author: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Sat Feb 1 15:09:04 2014 -0500
- first pass at new naming approach
reflection now updates the PKC in place.
- support the use case of the empty PrimaryKeyConstraint in order to specify
constraint options; the columns marked as primary_key=True will now be gathered
into the columns collection, rather than being ignored. [ticket:2910]
- add validation such that column specification should only take place
in the PrimaryKeyConstraint directly, or by using primary_key=True flags;
if both are present, they have to match exactly, otherwise the condition is
assumed to be ambiguous, and a warning is emitted; the old behavior of
using the PKC columns only is maintained.
type such as "charset" and "collation". While MySQL wants all character-
based CAST calls to use the CHAR type, we now create a real CHAR
object at CAST time and copy over all the parameters it has, so that
an expression like ``cast(x, mysql.TEXT(charset='utf8'))`` will
render ``CAST(t.col AS CHAR CHARACTER SET utf8)``.
- Added new "unicode returns" detection to the MySQL dialect and
to the default dialect system overall, such that any dialect
can add extra "tests" to the on-first-connect "does this DBAPI
return unicode directly?" detection. In this case, we are
adding a check specifically against the "utf8" encoding with
an explicit "utf8_bin" collation type (after checking that
this collation is available) to test for some buggy unicode
behavior observed with MySQLdb version 1.2.3. While MySQLdb
has resolved this issue as of 1.2.4, the check here should
guard against regressions. The change also allows the "unicode"
checks to log in the engine logs, which was not previously
the case. [ticket:2906]
_reset_agent, so that it's local to the various begin_impl(),
rollback_impl(), etc. this allows setting/resetting of the flag
to be symmetric.
- don't set _reset_agent if it's not None, don't unset it if it isn't
our own transaction.
- make sure we clean it out in close().
- basically, we're dealing here with pools using "threadlocal" that have a
counter, other various mismatches that the tests bring up
- test for recover() now has to invalidate() the previous connection,
because closing it actually rolls it back (e.g. this test was relying
on the broken behavior).
:class:`.RootTransaction` or :class:`.TwoPhaseTransaction`
with its immediate :class:`._ConnectionFairy` as a "reset handler"
for the span of that transaction, which takes over the task
of calling commit() or rollback() for the "reset on return" behavior
of :class:`.Pool` if the transaction was not otherwise completed.
This resolves the issue that a picky transaction
like that of MySQL two-phase will be
properly closed out when the connection is closed without an
explicit rollback or commit (e.g. no longer raises "XAER_RMFAIL"
in this case - note this only shows up in logging as the exception
is not propagated within pool reset).
This issue would arise e.g. when using an orm
:class:`.Session` with ``twophase`` set, and then
:meth:`.Session.close` is called without an explicit rollback or
commit. The change also has the effect that you will now see
an explicit "ROLLBACK" in the logs when using a :class:`.Session`
object in non-autocommit mode regardless of how that session was
discarded. Thanks to Jeff Dairiki and Laurence Rowe for isolating
the issue here. [ticket:2907]
events including auto-invalidation, which is useful both for tests here as well as
detecting failure conditions within the "reset" or "close" cases.
- rename the argument for PoolEvents.reset() to dbapi_connection and connection_record
to be consistent with everything else.
- add new documentation sections on invalidation, including auto-invalidation
and the invalidation process within the pool.
- add _ConnectionFairy and _ConnectionRecord to the pool documentation. Establish
docs for common _ConnectionFairy/_ConnectionRecord methods and accessors and
have PoolEvents docs refer to _ConnectionRecord,
since it is passed to all events. Rename a few _ConnectionFairy methods that are actually
private to pool such as _checkout(), _checkin() and _checkout_existing(); there should not
be any external code calling these
we will be able to parse dialect-specific arguments from string
configuration dictionaries. Dialect classes can now provide their
own list of parameter types and string-conversion routines.
The feature is not yet used by the built-in dialects, however.
[ticket:2875]
of dbapi.Error (such as ``TypeError``, ``NotImplementedError``, etc.)
will propagate the exception unchanged. Previously,
the error handling specific to the ``connect()`` routine would both
inappropriately run the exception through the dialect's
:meth:`.Dialect.is_disconnect` routine as well as wrap it in
a :class:`sqlalchemy.exc.DBAPIError`. It is now propagated unchanged
in the same way as occurs within the execute process. [ticket:2881]
- add tests for this in test_parseconnect, but also add tests in test_execute
to ensure the execute() behavior as well
attempts when an existing connection attempt is blocking. Previously,
the production of new connections was serialized within the block
that monitored overflow; the overflow counter is now altered within
it's own critical section outside of the connection process itself.
[ticket:2880]
connection to be available, such that for a connection pool
with no timeout specified, it will every half a second break out of
the wait to check for the so-called "abort" flag, which allows the
waiter to break out in case the whole connection pool was dumped;
normally the waiter should break out due to a notify_all() but it's
possible this notify_all() is missed in very slim cases.
This is an extension of logic first introduced in 0.8.0, and the
issue has only been observed occasionally in stress tests.
"@", or "/" must be encoded." - so re-apply encoding to both password
and username, don't encode spaces as plus signs, don't encode any chars
outside of :, @, / on stringification - but we still parse for any
%XX character (is that right?)
:func:`.make_url` function **no longer URL encode the password**.
Database passwords that include characters like spaces, plus signs
and anything else should now represent these characters directly,
without any URL escaping. [ticket:2873]
when a pre-DBAPI :class:`.StatementError` were raised within
:meth:`.Connection.execute`, causing encoding errors for
non-ASCII statements. The stringification now remains within
Python unicode thus avoiding encoding errors. [ticket:2871]
of the incoming :class:`.Column` would prevent primary key constraints,
indexes, and foreign key constraints from being correctly reflected.
Also in 0.8.3. [ticket:2811]
the import structure of many core modules.
``sqlalchemy.schema`` and ``sqlalchemy.types``
remain in the top-level package, but are now just lists of names
that pull from within ``sqlalchemy.sql``. Their implementations
are now broken out among ``sqlalchemy.sql.type_api``, ``sqlalchemy.sql.sqltypes``,
``sqlalchemy.sql.schema`` and ``sqlalchemy.sql.ddl``, the last of which was
moved from ``sqlalchemy.engine``. ``sqlalchemy.sql.expression`` is also
a namespace now which pulls implementations mostly from ``sqlalchemy.sql.elements``,
``sqlalchemy.sql.selectable``, and ``sqlalchemy.sql.dml``.
Most of the "factory" functions
used to create SQL expression objects have been moved to classmethods
or constructors, which are exposed in ``sqlalchemy.sql.expression``
using a programmatic system. Care has been taken such that all the
original import namespaces remain intact and there should be no impact
on any existing applications. The rationale here was to break out these
very large modules into smaller ones, provide more manageable lists
of function names, to greatly reduce "import cycles" and clarify the
up-front importing of names, and to remove the need for redundant
functions and documentation throughout the expression package.
is recreated, due to a disconnect error. This fixes a particular
issue in the Oracle 8 dialect, but in general the dialect.initialize()
phase should only be once per dialect. Also in 0.8.3. [ticket:2776]
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()
actual mock objects from the mock library. I'd like to use mock
for new tests so we might as well use it in obvious places.
- use unittest.mock in py3.3
- changelog
- add a note to README.unittests
- add tests_require in setup.py
- have tests import from sqlalchemy.testing.mock
- apply usage of mock to one of the event tests. we can be using
this approach all over the place.
Mike Bayer