Implemented support for the GROUPS frame specification in window functions
by adding :paramref:`_sql.over.groups` option to :func:`_sql.over`
and :meth:`.FunctionElement.over`. Pull request courtesy Kaan Dikmen.
Fixes: #12450Closes: #12445
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/12445
Pull-request-sha: c0808e135f
Change-Id: I9ff504a9c9650485830c4a0eaf44162898a3a2ad
When building a PostgreSQL ``ARRAY`` literal using
:class:`_postgresql.array` with an empty ``clauses`` argument, the
:paramref:`_postgresql.array.type_` parameter is now significant in that it
will be used to render the resulting ``ARRAY[]`` SQL expression with a
cast, such as ``ARRAY[]::INTEGER``. Pull request courtesy Denis Laxalde.
Fixes: #12432Closes: #12435
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/12435
Pull-request-sha: 9633d3c15d
Change-Id: I29ed7bd0562b82351d22de0658fb46c31cfe44f6
Added the ability to create custom SQL constructs that can define new
clauses within SELECT, INSERT, UPDATE, and DELETE statements without
needing to modify the construction or compilation code of of
:class:`.Select`, :class:`.Insert`, :class:`.Update`, or :class:`.Delete`
directly. Support for testing these constructs, including caching support,
is present along with an example test suite. The use case for these
constructs is expected to be third party dialects for NewSQL or other novel
styles of database that introduce new clauses to these statements. A new
example suite is included which illustrates the ``QUALIFY`` SQL construct
used by several NewSQL databases which includes a cachable implementation
as well as a test suite.
Since these extensions start to make it a bit crowded with how many
kinds of "options" we have on statements, did some naming /
documentation changes with existing constructs on Executable, in
particular to distinguish ExecutableOption from SyntaxExtension.
Fixes: #12195
Change-Id: I4a44ee5bbc3d8b1b640837680c09d25b1b7077af
Fixed SQL composition bug which impacted caching where using a ``None``
value inside of an ``in_()`` expression would bypass the usual "expanded
bind parameter" logic used by the IN construct, which allows proper caching
to take place.
Fixes: #12314
References: #12312
Change-Id: I0d2fc4e15c73407379ba368dd4ee32660fc66259
Follow up of 🎫`11471` to fix caching issue where using the
:meth:`.CompoundSelectState.add_cte` method of the
:class:`.CompoundSelectState` construct would not set a correct cache key
which distinguished between different CTE expressions. Also added tests
that would detect issues similar to the one fixed in 🎫`11544`.
Fixes: #11471
Change-Id: Iae6a91077c987d83cd70ea826daff42855491330
Fixed caching issue where the
:paramref:`_sql.Select.with_for_update.key_share` element of
:meth:`_sql.Select.with_for_update` was not considered as part of the cache
key, leading to incorrect caching if different variations of this parameter
were used with an otherwise identical statement.
Also repairs a traversal issue where the ``of`` element of
``ForUpdateArg`` when set to ``None`` cannot be compared against a
non-None element because the traversal defines it as a clauselist.
Traversal in this case is adjusted to accommodate for this case so that
we dont need to create a risky-to-backport change to ``ForUpdateArg``
itself.
Fixes: #11544
Change-Id: Ie8a50716df06977af58b0c22a8c10e1b64d972b9
Enhanced the caching structure of the :paramref:`.over.rows` and
:paramref:`.over.range` so that different numerical values for the rows /
range fields are cached on the same cache key, to the extent that the
underlying SQL does not actually change (i.e. "unbounded", "current row",
negative/positive status will still change the cache key). This prevents
the use of many different numerical range/rows value for a query that is
otherwise identical from filling up the SQL cache.
Note that the semi-private compiler method ``_format_frame_clause()``
is removed by this fix, replaced with a new method
``visit_frame_clause()``. Third party dialects which may have referred
to this method will need to change the name and revise the approach to
rendering the correct SQL for that dialect.
This patch introduces a new ClauseElement called _FrameClause which
stores the integer range values separately and within cache-compatible
BindParameter objects from the "type" which
can be unbounded, current, preceding, or following, represented by
a _FrameClauseType enum. The negative
sign is also stripped from the integer and represented within the
_FrameClauseType. Tests from #11514 are adapted to include
a test for SQL Server's "literal_execute" flag taking effect so
that literal numeric values aren't stored in the cache.
Fixes: #11515
Change-Id: I8aad368ffef9f06cb5c3f8c4e971fadef029ffd5
Fixed caching issue where using the :meth:`.TextualSelect.add_cte` method
of the :class:`.TextualSelect` construct would not set a correct cache key
which distinguished between different CTE expressions.
Fixes: #11471
Change-Id: Ia9ce2c8cfd128f0f130aa9b26448dc23d994c324
Adjusted the fix made in 🎫`10570`, released in 2.0.23, where new
logic was added to reconcile possibly changing bound parameter values
across cache key generations used within the :func:`_orm.with_expression`
construct. The new logic changes the approach by which the new bound
parameter values are associated with the statement, avoiding the need to
deep-copy the statement which can result in a significant performance
penalty for very deep / complex SQL constructs. The new approach no longer
requires this deep-copy step.
Fixes: #11085
Change-Id: Ia51eb4e949c8f37af135399925a9916b9ed4ad2f
Fixed issue where the :meth:`_sql.ColumnOperators.regexp_match`
when using "flags" would not produce a "stable" cache key, that
is, the cache key would keep changing each time causing cache pollution.
The same issue existed for :meth:`_sql.ColumnOperators.regexp_replace`
with both the flags and the actual replacement expression.
The flags are now represented as fixed modifier strings rendered as
safestrings rather than bound parameters, and the replacement
expression is established within the primary portion of the "binary"
element so that it generates an appropriate cache key.
Note that as part of this change, the
:paramref:`_sql.ColumnOperators.regexp_match.flags` and
:paramref:`_sql.ColumnOperators.regexp_replace.flags` have been modified to
render as literal strings only, whereas previously they were rendered as
full SQL expressions, typically bound parameters. These parameters should
always be passed as plain Python strings and not as SQL expression
constructs; it's not expected that SQL expression constructs were used in
practice for this parameter, so this is a backwards-incompatible change.
The change also modifies the internal structure of the expression
generated, for :meth:`_sql.ColumnOperators.regexp_replace` with or without
flags, and for :meth:`_sql.ColumnOperators.regexp_match` with flags. Third
party dialects which may have implemented regexp implementations of their
own (no such dialects could be located in a search, so impact is expected
to be low) would need to adjust the traversal of the structure to
accommodate.
Fixed issue in mostly-internal :class:`.CacheKey` construct where the
``__ne__()`` operator were not properly implemented, leading to nonsensical
results when comparing :class:`.CacheKey` instances to each other.
Fixes: #10042
Change-Id: I2e245f81d7ee7136ad04cf77be35f9745c5da5e5
Fixed critical SQL caching issue where use of the :meth:`_sql.Operators.op`
custom operator function would not produce an appropriate cache key,
leading to reduce the effectiveness of the SQL cache.
Fixes: #9506
Change-Id: I3eab1ddb5e09a811ad717161a59df0884cdf70ed
Added :class:`_expression.ScalarValues` that can be used as a column
element allowing using :class:`_expression.Values` inside IN clauses
or in conjunction with ``ANY`` or ``ALL`` collection aggregates.
This new class is generated using the method
:meth:`_expression.Values.scalar_values`.
The :class:`_expression.Values` instance is now coerced to a
:class:`_expression.ScalarValues` when used in a ``IN`` or ``NOT IN``
operation.
Fixes: #6289
Change-Id: Iac22487ccb01553684b908e54d01c0687fa739f1
command run is "pyupgrade --py37-plus --keep-runtime-typing --keep-percent-format <files...>"
pyupgrade will change assert_ to assertTrue. That was reverted since assertTrue does not
exists in sqlalchemy fixtures
Change-Id: Ie1ed2675c7b11d893d78e028aad0d1576baebb55
also adjusted CacheKeyFixture to be a general purpose
fixture so that sub-components / dialects can run
their own cache key tests.
Fixes: #8574
Change-Id: I6c66107856aee11e548d357cea77bceee3e316a0
Fixed issue where use of the :func:`_sql.table` construct, passing a string
for the :paramref:`_sql.table.schema` parameter, would fail to take the
"schema" string into account when producing a cache key, thus leading to
caching collisions if multiple, same-named :func:`_sql.table` constructs
with different schemas were used.
Fixes: #8441
Change-Id: Ic4b55b3e8ec53b4c88ba112691bdf60ea1d4c448
the pep484 task becomes more intense as there is mounting
pressure to come up with a consistency in how data moves
from end-user to instance variable.
current thinking is coming into:
1. there are _typing._XYZArgument objects that represent "what the
user sent"
2. there's the roles, which represent a kind of "filter" for different
kinds of objects. These are mostly important as the argument
we pass to coerce().
3. there's the thing that coerce() returns, which should be what the
construct uses as its internal representation of the thing.
This is _typing._XYZElement.
but there's some controversy over whether or
not we should pass actual ClauseElements around by their role
or not. I think we shouldn't at the moment, but this makes the
"role-ness" of something a little less portable. Like, we have
to set DMLTableRole for TableClause, Join, and Alias, but then
also we have to repeat those three types in order to set up
_DMLTableElement.
Other change introduced here, there was a deannotate=True
for the left/right of a sql.join(). All tests pass without that.
I'd rather not have that there as if we have a join(A, B) where
A, B are mapped classes, we want them inside of the _annotations.
The rationale seems to be performance, but this performance can
be illustrated to be on the compile side which we hope is cached
in the normal case.
CTEs now accommodate for text selects including recursive.
Get typing to accommodate "util.preloaded" cleanly; add "preloaded"
as a real module. This seemed like we would have needed
pep562 `__getattr__()` but we don't, just set names in
globals() as we import them.
References: #6810
Change-Id: I34d17f617de2fe2c086fc556bd55748dc782faf0
The ``literal_execute`` parameter now takes part of the cache
generation of a bindparam, since it changes the sql string generated
by the compiler.
Previously the correct bind values were used, but the ``literal_execute``
would be ignored on subsequent executions of the same query.
Fixes: #7876
Change-Id: I6bf887f1a2fe31f9d0ab68f5b4ff315004d006b2
Fixed a regression in the test suite where the test called
``CompareAndCopyTest::test_all_present`` would fail on some platforms due
to additional testing artifacts being detected. Pull request courtesy Nils
Philippsen.
In some circumstances, ephemeral class objects that are created within
the scope of a test method don't seem to be garbage collected directly
on exit. Filter out classes created in test modules.
Fixes: #7450Closes: #7451
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/7451
Pull-request-sha: 135a8aaba2
Change-Id: I621967bd916089dc1e3f98625fd2a852cd9fd712
This patch adds new warnings for all elements that
don't indicate their caching behavior, including user-defined
ClauseElement subclasses and third party dialects.
it additionally adds new documentation to discuss an apparent
performance degradation in 1.4 when caching is disabled as a
result in the significant expense incurred by ORM
lazy loaders, which in 1.3 used BakedQuery so were actually
cached.
As a result of adding the warnings, a fair degree of
lesser used SQL expression objects identified that they did not
define caching behavior so would have been producing
``[no key]``, including PostgreSQL constructs ``hstore``
and ``array``. These have been amended to use inherit
cache where appropriate. "on conflict" constructs in
PostgreSQL, MySQL, SQLite still explicitly don't generate
a cache key at this time.
The change also adds a test for all constructs via
assert_compile() to assert they will not generate cache
warnings.
Fixes: #7394
Change-Id: I85958affbb99bfad0f5efa21bc8f2a95e7e46981
Extended the ``cache_ok`` flag and corresponding warning message if this
flag is not defined, a behavior first established for
:class:`.TypeDecorator` as part of 🎫`6436`, to also take place for
:class:`.UserDefinedType`, by generalizing the flag and associated caching
logic to a new common base for these two types, :class:`.ExternalType`.
The change means any current :class:`.UserDefinedType` will now cause SQL
statement caching to no longer take place for statements which make use of
the datatype, along with a warning being emitted, unless the class defines
the :attr:`.UserDefinedType.cache_ok` flag as True. If the datatype cannot
form a deterministic, hashable cache key derived from its arguments, it may return
False which will continue to keep caching disabled but will suppress the
warning. In particular, custom datatypes currently used in packages such as
SQLAlchemy-utils will need to implement this flag. The issue was observed
as a result of a SQLAlchemy-utils datatype that is not currently cacheable.
Fixes: #7319
Change-Id: Ie0b5d4587df87bfe66d2fe7cd4585c3882584575
Repaired issue in new :paramref:`_sql.HasCTE.cte.nesting` parameter
introduced with 🎫`4123` where a recursive :class:`_sql.CTE` using
:paramref:`_sql.HasCTE.cte.recursive` in typical conjunction with UNION
would not compile correctly. Additionally makes some adjustments so that
the :class:`_sql.CTE` construct creates a correct cache key.
Pull request courtesy Eric Masseran.
Fixes: #4123
> This has not been caught by the tests because the nesting recursive
queries there did not union against itself, eg there was only the i
root clause...
- Now tests are real recursive queries
- Add tests on aliased nested CTEs (recursive or not)
- Adapt the `_restates` attribute to use it as a reference
- Add some docs around to explain some variables usage
Closes: #7133
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/7133
Pull-request-sha: 2633f34f7f
Change-Id: I15512c94e1bc1f52afc619d82057ca647d274e92
Fixed critical caching issue where the ORM's persistence feature using
INSERT..RETURNING would cache an incorrect query when mixing the "bulk
save" and standard "flush" forms of INSERT.
Fixes: #6793
Change-Id: Ifeb61c1226d3fa6d5e1c2e29b6f5ff77a27d6a2d
Added new method :meth:`_sql.HasCTE.add_cte` to each of the
:func:`_sql.select`, :func:`_sql.insert`, :func:`_sql.update` and
:func:`_sql.delete` constructs. This method will add the given
:class:`_sql.CTE` as an "independent" CTE of the statement, meaning it
renders in the WITH clause above the statement unconditionally even if it
is not otherwise referenced in the primary statement. This is a popular use
case on the PostgreSQL database where a CTE is used for a DML statement
that runs against database rows independently of the primary statement.
Fixes: #6752
Change-Id: Ibf635763e40269cbd10f4c17e208850d8e8d0188
Fixed regression where the :func:`_sql.tablesample` construct would fail to
be executable when constructed given a floating-point sampling value not
embedded within a SQL function.
Fixes: #6735
Change-Id: I557bcd4bdbffc4329ad69d5659ba99b1c8deb554
Fixed further regressions in the same area as that of 🎫`6052` where
loader options as well as invocations of methods like
:meth:`_orm.Query.join` would fail if the left side of the statement for
which the option/join depends upon were replaced by using the
:meth:`_orm.Query.with_entities` method, or when using 2.0 style queries
when using the :meth:`_sql.Select.with_only_columns` method. A new set of
state has been added to the objects which tracks the "left" entities that
the options / join were made against which is memoized when the lead
entities are changed.
Fixes: #6503Fixes: #6253
Change-Id: I211b2af98b0b20d1263fb15dc513884dcc5de6a4
The :class:`.TypeDecorator` class will now emit a warning when used in SQL
compilation with caching unless the ``.cache_ok`` flag is set to ``True``
or ``False``. ``.cache_ok`` indicates that all the parameters passed to the
object are safe to be used as a cache key, ``False`` means they are not.
Fixes: #6436
Change-Id: Ib1bb7dc4b124e38521d615c2e2e691e4915594fb
Enhanced the "expanding" feature used for :meth:`_sql.ColumnOperators.in_`
operations to infer the type of expression from the right hand list of
elements, if the left hand side does not have any explicit type set up.
This allows the expression to support stringification among other things.
In 1.3, "expanding" was not automatically used for
:meth:`_sql.ColumnOperators.in_` expressions, so in that sense this change
fixes a behavioral regression.
Fixes: #6222
Change-Id: Icdfda1e2c226a21896cafd6d8f251547794451c2
Fixed issue where using a ``func`` that includes dotted packagenames would
fail to be cacheable by the SQL caching system due to a Python list of
names that needed to be a tuple.
Fixes: #6101
Change-Id: I1d4bb5bf230b83596c59b6a04aa498f18ecd9613
Fixed issue in new 1.4/2.0 style ORM queries where a statement-level label
style would not be preserved in the keys used by result rows; this has been
applied to all combinations of Core/ORM columns / session vs. connection
etc. so that the linkage from statement to result row is the same in all
cases.
also repairs a cache key bug where query.from_statement()
vs. select().from_statement() would not be disambiguated; the
compile options were not included in the cache key for
FromStatement.
Fixes: #5933
Change-Id: I22f6cf0f0b3360e55299cdcb2452cead2b2458ea
Implemented support for "table valued functions" along with additional
syntaxes supported by PostgreSQL, one of the most commonly requested
features. Table valued functions are SQL functions that return lists of
values or rows, and are prevalent in PostgreSQL in the area of JSON
functions, where the "table value" is commonly referred towards as the
"record" datatype. Table valued functions are also supported by Oracle and
SQL Server.
Moved from I5b093b72533ef695293e737eb75850b9713e5e03 due
to accidental push
Fixes: #3566
Change-Id: Iea36d04c80a5ed3509dcdd9ebf0701687143fef5
Replace :meth:`_orm.Query.with_labels` and
:meth:`_sql.GenerativeSelect.apply_labels` with explicit getters and
setters ``get_label_style`` and ``set_label_style`` to accommodate the
three supported label styles: ``LABEL_STYLE_DISAMBIGUATE_ONLY`` (default),
``LABEL_STYLE_TABLENAME_PLUS_COL``, and ``LABEL_STYLE_NONE``.
In addition, for Core and "future style" ORM queries,
``LABEL_STYLE_DISAMBIGUATE_ONLY`` is now the default label style. This
style differs from the existing "no labels" style in that labeling is
applied in the case of column name conflicts; with ``LABEL_STYLE_NONE``, a
duplicate column name is not accessible via name in any case.
For legacy ORM queries using :class:`_query.Query`, the table-plus-column
names labeling style applied by ``LABEL_STYLE_TABLENAME_PLUS_COL``
continues to be used so that existing test suites and logging facilities
see no change in behavior by default, however this style of labeling is no
longer required for SQLAlchemy queries to function, as result sets are
commonly matched to columns using a positional approach since SQLAlchemy
1.0.
Within test suites, all use of apply_labels() / use_labels
now uses the new methods. New tests added to
test/sql/test_deprecations.py nad test/orm/test_deprecations.py
to cover just the old apply_labels() method call. Tests
in ORM that made explicit use apply_labels()/ etc. where it isn't needed
for the ORM to work correctly use default label style now.
Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Fixes: #4757
Change-Id: I5fdcd2ed4ae8c7fe62f8be2b6d0e8f66409b6a54
To allow the "connection" pytest fixture and others work
correctly in conjunction with setup/teardown that expects
to be external to the transaction, remove and prevent any usage
of "xdist" style names that are hardcoded by pytest to run
inside of fixtures, even function level ones. Instead use
pytest autouse fixtures to implement our own
r"setup|teardown_test(?:_class)?" methods so that we can ensure
function-scoped fixtures are run within them. A new more
explicit flow is set up within plugin_base and pytestplugin
such that the order of setup/teardown steps, which there are now
many, is fully documented and controllable. New granularity
has been added to the test teardown phase to distinguish
between "end of the test" when lock-holding structures on
connections should be released to allow for table drops,
vs. "end of the test plus its teardown steps" when we can
perform final cleanup on connections and run assertions
that everything is closed out.
From there we can remove most of the defensive "tear down everything"
logic inside of engines which for many years would frequently dispose
of pools over and over again, creating for a broken and expensive
connection flow. A quick test shows that running test/sql/ against
a single Postgresql engine with the new approach uses 75% fewer new
connections, creating 42 new connections total, vs. 164 new
connections total with the previous system.
As part of this, the new fixtures metadata/connection/future_connection
have been integrated such that they can be combined together
effectively. The fixture_session(), provide_metadata() fixtures
have been improved, including that fixture_session() now strongly
references sessions which are explicitly torn down before
table drops occur afer a test.
Major changes have been made to the
ConnectionKiller such that it now features different "scopes" for
testing engines and will limit its cleanup to those testing
engines corresponding to end of test, end of test class, or
end of test session. The system by which it tracks DBAPI
connections has been reworked, is ultimately somewhat similar to
how it worked before but is organized more clearly along
with the proxy-tracking logic. A "testing_engine" fixture
is also added that works as a pytest fixture rather than a
standalone function. The connection cleanup logic should
now be very robust, as we now can use the same global
connection pools for the whole suite without ever disposing
them, while also running a query for PostgreSQL
locks remaining after every test and assert there are no open
transactions leaking between tests at all. Additional steps
are added that also accommodate for asyncio connections not
explicitly closed, as is the case for legacy sync-style
tests as well as the async tests themselves.
As always, hundreds of tests are further refined to use the
new fixtures where problems with loose connections were identified,
largely as a result of the new PostgreSQL assertions,
many more tests have moved from legacy patterns into the newest.
An unfortunate discovery during the creation of this system is that
autouse fixtures (as well as if they are set up by
@pytest.mark.usefixtures) are not usable at our current scale with pytest
4.6.11 running under Python 2. It's unclear if this is due
to the older version of pytest or how it implements itself for
Python 2, as well as if the issue is CPU slowness or just large
memory use, but collecting the full span of tests takes over
a minute for a single process when any autouse fixtures are in
place and on CI the jobs just time out after ten minutes.
So at the moment this patch also reinvents a small version of
"autouse" fixtures when py2k is running, which skips generating
the real fixture and instead uses two global pytest fixtures
(which don't seem to impact performance) to invoke the
"autouse" fixtures ourselves outside of pytest.
This will limit our ability to do more with fixtures
until we can remove py2k support.
py.test is still observed to be much slower in collection in the
4.6.11 version compared to modern 6.2 versions, so add support for new
TOX_POSTGRESQL_PY2K and TOX_MYSQL_PY2K environment variables that
will run the suite for fewer backends under Python 2. For Python 3
pin pytest to modern 6.2 versions where performance for collection
has been improved greatly.
Includes the following improvements:
Fixed bug in asyncio connection pool where ``asyncio.TimeoutError`` would
be raised rather than :class:`.exc.TimeoutError`. Also repaired the
:paramref:`_sa.create_engine.pool_timeout` parameter set to zero when using
the async engine, which previously would ignore the timeout and block
rather than timing out immediately as is the behavior with regular
:class:`.QueuePool`.
For asyncio the connection pool will now also not interact
at all with an asyncio connection whose ConnectionFairy is
being garbage collected; a warning that the connection was
not properly closed is emitted and the connection is discarded.
Within the test suite the ConnectionKiller is now maintaining
strong references to all DBAPI connections and ensuring they
are released when tests end, including those whose ConnectionFairy
proxies are GCed.
Identified cx_Oracle.stmtcachesize as a major factor in Oracle
test scalability issues, this can be reset on a per-test basis
rather than setting it to zero across the board. the addition
of this flag has resolved the long-standing oracle "two task"
error problem.
For SQL Server, changed the temp table style used by the
"suite" tests to be the double-pound-sign, i.e. global,
variety, which is much easier to test generically. There
are already reflection tests that are more finely tuned
to both styles of temp table within the mssql test
suite. Additionally, added an extra step to the
"dropfirst" mechanism for SQL Server that will remove
all foreign key constraints first as some issues were
observed when using this flag when multiple schemas
had not been torn down.
Identified and fixed two subtle failure modes in the
engine, when commit/rollback fails in a begin()
context manager, the connection is explicitly closed,
and when "initialize()" fails on the first new connection
of a dialect, the transactional state on that connection
is still rolled back.
Fixes: #5826Fixes: #5827
Change-Id: Ib1d05cb8c7cf84f9a4bfd23df397dc23c9329bfe
1. Improve coercions._deep_is_literal to check sequences
for clause elements, thus allowing a phrase like
lambda: col.in_([literal("x"), literal("y")]) to be handled
2. revise closure variable caching completely. All variables
entering must be part of a closure cache key or rejected.
only objects that can be resolved to HasCacheKey or FunctionType
are accepted; all other types are rejected. This adds a high
degree of strictness to lambdas and will make them a little more
awkward to use in some cases, however prevents several classes
of critical issues:
a. previously, a lambda that had an expression derived from
some kind of state, like "self.x", or "execution_context.session.foo"
would produce a closure cache key from "self" or "execution_context",
objects that can very well be per-execution and would therefore
cause a AnalyzedFunction objects to overflow. (memory won't leak
as it looks like an LRUCache is already used for these)
b. a lambda, such as one used within DeferredLamdaElement, that
produces different SQL expressions based on the arguments
(which is in fact what it's supposed to do), however it would
through the use of conditionals produce different bound parameter
combinations, leading to literal parameters not tracked properly.
These are now rejected as uncacheable whereas previously they would
again be part of the closure cache key, causing an overflow of
AnalyizedFunction objects.
3. Ensure non-mapped mixins are handled correctly by
with_loader_criteria().
4. Fixed bug in lambda SQL system where we are not supposed to allow a Python
function to be embedded in the lambda, since we can't predict a bound value
from it. While there was an error condition added for this, it was not
tested and wasn't working; an informative error is now raised.
5. new docs for lambdas
6. consolidated changelog for all of these
Fixes: #5760Fixes: #5765Fixes: #5766Fixes: #5768Fixes: #5770
Change-Id: Iedaa636c3225fad496df23b612c516c8ab247ab7
Add support to ``FETCH {FIRST | NEXT} [ count ] {ROW | ROWS}
{ONLY | WITH TIES}`` in the select for the supported backends,
currently PostgreSQL, Oracle and MSSQL.
Fixes: #5576
Change-Id: Ibb5871a457c0555f82b37e354e7787d15575f1f7
It's better, the majority of these changes look more readable to me.
also found some docstrings that had formatting / quoting issues.
Change-Id: I582a45fde3a5648b2f36bab96bad56881321899b
This change includes mainly that the bracketed use within
select() is moved to positional, and keyword arguments are
removed from calls to the select() function. it does not
yet fully address other issues such as keyword arguments passed
to the table.select().
Additionally, allows False / None to both be considered
as "disable" for all of select.correlate(), select.correlate_except(),
query.correlate(), which establishes consistency with
passing of ``False`` for the legact select(correlate=False)
argument.
Change-Id: Ie6c6e6abfbd3d75d4c8de504c0cf0159e6999108
Added the ability to add arbitrary criteria to the ON clause generated
by a relationship attribute in a query, which applies to methods such
as :meth:`_query.Query.join` as well as loader options like
:func:`_orm.joinedload`. Additionally, a "global" version of the option
allows limiting criteria to be applied to particular entities in
a query globally.
Documentation is minimal at this point, new examples will
be coming in a subsequent commit.
Some adjustments to execution options in how they are represented
in the ORMExecuteState as well as well as a few ORM tests that
forgot to get merged in a preceding commit.
Fixes: #4472
Change-Id: I2b8fc57092dedf35ebd16f6343ad0f0d7d332beb
in order to accommodate relationship loaders
with lambda caching, a lot more is needed. This is
a full refactor of the lambda system such that it
now has two levels of caching; the first level caches what
can be known from the __code__ element, then the next level
of caching is against the lambda itself and the contents
of __closure__. This allows for the elements inside
the lambdas, like columns and entities, to change and
then be part of the cache key. Lazy/selectinloads' use of
baked queries had to add distinct cache key elements,
which was attempted here but overall things needed to be
more robust than that.
This commit is broken out from the very long and sprawling
commit at Id6b5c03b1ce9ddb7b280f66792212a0ef0a1c541 .
Change-Id: I29a513c98917b1d503abfdd61e6b6e8800851aa8
This is kind of a mixed bag of all kinds to help get us
to 1.4 betas. The documentation stuff is a work in
progress. Lots of other relatively small changes to
APIs and things. More commits will follow to continue
improving the documentation and transitioning to the
1.4/2.0 hybrid documentation. In particular some refinements
to Session usage models so that it can match Engine's
scoping / transactional patterns, and a decision to
start moving away from "subtransactions" completely.
* add select().from_statement() to produce FromStatement in an
ORM context
* begin referring to select() that has "plugins" for the few edge
cases where select() will have ORM-only behaviors
* convert dynamic.AppenderQuery to its own object that can use
select(), though at the moment it uses Query to support legacy
join calling forms.
* custom query classes for AppenderQuery are replaced by
do_orm_execute() hooks for custom actions, a separate gerrit
will document this
* add Session.get() to replace query.get()
* Deprecate session.begin->subtransaction. propose within the
test suite a hypothetical recipe for apps that rely on this
pattern
* introduce Session construction level context manager,
sessionmaker context manager, rewrite the whole top of the
session_transaction.rst documentation. Establish context manager
patterns for Session that are identical to engine
* ensure same begin_nested() / commit() behavior as engine
* devise all new "join into an external transaction" recipe,
add test support for it, add rules into Session so it
just works, write new docs. need to ensure this doesn't
break anything
* vastly reduce the verbosity of lots of session docs as
I dont think people read this stuff and it's difficult
to keep current in any case
* constructs like case(), with_only_columns() really need
to move to *columns, add a coercion rule to just change
these.
* docs need changes everywhere I look. in_() is not in
the Core tutorial? how do people even know about it?
Remove tons of cruft from Select docs, etc.
* build a system for common ORM options like populate_existing
and autoflush to populate from execution options.
* others?
Change-Id: Ia4bea0f804250e54d90b3884cf8aab8b66b82ecf
Kaan