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* Dont return outer transaction for _subtrans flagMike Bayer2021-04-091-1/+3
| | | | | | | | | | | | | | | | | | | Fixed critical regression where the :class:`_orm.Session` could fail to "autobegin" a new transaction when a flush occurred without an existing transaction in place, implicitly placing the :class:`_orm.Session` into legacy autocommit mode which commit the transaction. The :class:`_orm.Session` now has a check that will prevent this condition from occurring, in addition to repairing the flush issue. Additionally, scaled back part of the change made as part of :ticket:`5226` which can run autoflush during an unexpire operation, to not actually do this in the case of a :class:`_orm.Session` using legacy :paramref:`_orm.Session.autocommit` mode, as this incurs a commit within a refresh operation. Fixes: #6233 Change-Id: Ia980e62a090e39e3e2a7fb77c95832ae784cc9a5
* Add test support for merge_frozen_resultMike Bayer2021-04-071-2/+2
| | | | | | | | | Fixed regression where the :func:`_orm.merge_frozen_result` function relied upon by the dogpile.caching example was not included in tests and began failing due to incorrect internal arguments. Fixes: #6211 Change-Id: I0b53d0f569c817994ad4827a3ddb1626fd2d082f
* Disable and disallow Result.unique() with yield_perMike Bayer2021-04-061-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixed critical regression where the :meth:`_orm.Query.yield_per` method in the ORM would set up the internal :class:`_engine.Result` to yield chunks at a time, however made use of the new :meth:`_engine.Result.unique` method which uniques across the entire result. This would lead to lost rows since the ORM is using ``id(obj)`` as the uniquing function, which leads to repeated identifiers for new objects as already-seen objects are garbage collected. 1.3's behavior here was to "unique" across each chunk, which does not actually produce "uniqued" results when results are yielded in chunks. As the :meth:`_orm.Query.yield_per` method is already explicitly disallowed when joined eager loading is in place, which is the primary rationale for the "uniquing" feature, the "uniquing" feature is now turned off entirely when :meth:`_orm.Query.yield_per` is used. This regression only applies to the legacy :class:`_orm.Query` object; when using :term:`2.0 style` execution, "uniquing" is not automatically applied. To prevent the issue from arising from explicit use of :meth:`_engine.Result.unique`, an error is now raised if rows are fetched from a "uniqued" ORM-level :class:`_engine.Result` if any :ref:`yield per <orm_queryguide_yield_per>` API is also in use, as the purpose of ``yield_per`` is to allow for arbitrarily large numbers of rows, which cannot be uniqued in memory without growing the number of entries to fit the complete result size. Fixes: #6206 Change-Id: I3770d1f2e9be44d82c83ca992afb912dcc17af05
* Use explicit names for mapper _get_clause parametersMike Bayer2021-03-171-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | Fixed a critical regression in the relationship lazy loader where the SQL criteria used to fetch a related many-to-one object could go stale in relation to other memoized structures within the loader if the mapper had configuration changes, such as can occur when mappers are late configured or configured on demand, producing a comparison to None and returning no object. Huge thanks to Alan Hamlett for their help tracking this down late into the night. The primary change is that mapper._get_clause() uses a fixed name for its bound parameters, which is memoized under a lambda statement in the case of many-to-one lazy loading. This has implications for some other logic namely the .compare() used by loader strategies to determine use_get needed to be adjusted. This change also repairs the lambda module's behavior of removing the "required" flag from bound parameters, which caused this issue to also fail silently rather than issuing an error for a required bind parameter. Fixes: #6055 Change-Id: I19e1aba9207a049873e0f13c19bad7541e223cfd
* Apply consistent labeling for all future style ORM queriesMike Bayer2021-02-111-1/+3
| | | | | | | | | | | | | | | | 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
* Merge "Fix many spell glitches in docstrings and comments"mike bayer2021-01-261-1/+1
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| * Fix many spell glitches in docstrings and commentsLele Gaifax2021-01-241-1/+1
| | | | | | | | | | | | | | | | | | | | These were revealed by running `pylint --disable all --enable spelling --spelling-dict en_US` over all sources. Closes: #5868 Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5868 Pull-request-sha: bb249195d92e3b806e81ecf1192d5a1b3cd5db48 Change-Id: I96080ec93a9fbd20ce21e9e16265b3c77f22bb14
* | Replace with_labels() and apply_labels() in ORM/CoreGord Thompson2021-01-261-1/+4
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* happy new yearMike Bayer2021-01-041-1/+1
| | | | Change-Id: Ic5bb19ca8be3cb47c95a0d3315d84cb484bac47c
* upgrade to black 20.8b1Mike Bayer2020-09-281-4/+2
| | | | | | | 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
* Raise if unique() not applied to 2.0 joined eager load resultsMike Bayer2020-09-211-0/+15
| | | | | | | | | | | | | | | | | | | | | | The automatic uniquing of rows on the client side is turned off for the new :term:`2.0 style` of ORM querying. This improves both clarity and performance. However, uniquing of rows on the client side is generally necessary when using joined eager loading for collections, as there will be duplicates of the primary entity for each element in the collection because a join was used. This uniquing must now be manually enabled and can be achieved using the new :meth:`_engine.Result.unique` modifier. To avoid silent failure, the ORM explicitly requires the method be called when the result of an ORM query in 2.0 style makes use of joined load collections. The newer :func:`_orm.selectinload` strategy is likely preferable for eager loading of collections in any case. This changeset also fixes an issue where ORM-style "single entity" results would not apply unique() correctly if results were returned as tuples. Fixes: #4395 Change-Id: Ie62e0cb68ef2a6d2120e968b79575a70d057212e
* See if the future is hereMike Bayer2020-08-281-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The docs are going to talk a lot about session.execute(select()) for ORM queries, and additionally it's much easier to help users with queries and such if we can use this new syntax. I'm hoping to see how hard it is to get a unified tutorial started that switches to new syntax. Basically, new syntax is much easier to explain and less buggy. But, if we are starting to present new syntax with the explicit goal of being easier to explain for less experienced programmers, the "future" thing is going to just be an impediment to that. See if we can remove "future" from session.execute(), so that ORM-enabled select() statements return ORM results at that level. This does not change the presence of the "future" flag for the Session's construction and for its transactional behaviors. The only perceptible change of the future flag for session.execute() is that session.execute(select()) where the statement has ORM entities in it now returns ORM new style tuples rather than old style tuples. Like mutating a URL, it's hopefully not very common that people are doing this. Change-Id: I0aa10322bb787d554d32772e3bc60548f1bf6206
* Implement rudimentary asyncio support w/ asyncpgMike Bayer2020-08-131-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | Using the approach introduced at https://gist.github.com/zzzeek/6287e28054d3baddc07fa21a7227904e We can now create asyncio endpoints that are then handled in "implicit IO" form within the majority of the Core internals. Then coroutines are re-exposed at the point at which we call into asyncpg methods. Patch includes: * asyncpg dialect * asyncio package * engine, result, ORM session classes * new test fixtures, tests * some work with pep-484 and a short plugin for the pyannotate package, which seems to have so-so results Change-Id: Idbcc0eff72c4cad572914acdd6f40ddb1aef1a7d Fixes: #3414
* Documentation updates for 1.4Mike Bayer2020-08-051-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * major additions to 1.4 migration doc; removed additional verbosity regarding caching methodology and reorganized the doc to present itself more as a "what's changed" guide * as we now have a path for asyncio, update that doc so that we aren't spreading obsolete information * updates to the 2.0 migration guide with latest info, however this is still an architecture doc and not a migration guide yet, will need further rework. * start really talking about 1.x vs. 2.0 style everywhere. Querying is most of the docs so this is going to be a prominent theme, start getting it to fit in * Add introductory documentation for ORM example sections as these are too sparse * new documentation for do_orm_execute(), many separate sections, adding deprecation notes to before_compile() and similar * new example suites to illustrate do_orm_execute(), with_loader_criteria() * modernized horizontal sharding examples and added a separate example to distinguish between multiple databases and single database w/ multiple tables use case * introducing DEEP ALCHEMY, will use zzzeeksphinx 1.1.6 * no name for the alchemist yet however the dragon's name is Flambé Change-Id: Id6b5c03b1ce9ddb7b280f66792212a0ef0a1c541
* Convert lazy loader, selectinload, load_on_ident to lambda statementsMike Bayer2020-08-051-41/+75
| | | | | | | | | Building on newly robust lambdas in I29a513c98917b1d503abfdd61e6b6e8800851aa8, convert key loading off of the "baked" system so that baked is no longer used by the ORM. Change-Id: I3abfb45dd6e50f84f29d39434caa0b550ce27864
* Convert remaining ORM APIs to support 2.0 styleMike Bayer2020-07-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Add future=True to create_engine/Session; unify select()Mike Bayer2020-07-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Several weeks of using the future_select() construct has led to the proposal there be just one select() construct again which features the new join() method, and otherwise accepts both the 1.x and 2.x argument styles. This would make migration simpler and reduce confusion. However, confusion may be increased by the fact that select().join() is different Current thinking is we may be better off with a few hard behavioral changes to old and relatively unknown APIs rather than trying to play both sides within two extremely similar but subtly different APIs. At the moment, the .join() thing seems to be the only behavioral change that occurs without the user taking any explicit steps. Session.execute() will still behave the old way as we are adding a future flag. This change also adds the "future" flag to Session() and session.execute(), so that interpretation of the incoming statement, as well as that the new style result is returned, does not occur for existing applications unless they add the use of this flag. The change in general is moving the "removed in 2.0" system further along where we want the test suite to fully pass even if the SQLALCHEMY_WARN_20 flag is set. Get many tests to pass when SQLALCHEMY_WARN_20 is set; this should be ongoing after this patch merges. Improve the RemovedIn20 warning; these are all deprecated "since" 1.4, so ensure that's what the messages read. Make sure the inforamtion link is on all warnings. Add deprecation warnings for parameters present and add warnings to all FromClause.select() types of methods. Fixes: #5379 Fixes: #5284 Change-Id: I765a0b912b3dcd0e995426427d8bb7997cbffd51 References: #5159
* Fix a wide variety of typos and broken linksaplatkouski2020-06-251-2/+2
| | | | | | | | | | | | Note the PR has a few remaining doc linking issues listed in the comment that must be addressed separately. Signed-off-by: aplatkouski <5857672+aplatkouski@users.noreply.github.com> Closes: #5371 Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5371 Pull-request-sha: 7e7d233cf3a0c66980c27db0fcdb3c7d93bc2510 Change-Id: I9c36e8d8804483950db4b42c38ee456e384c59e3
* Turn on caching everywhere, add loggingMike Bayer2020-06-101-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A variety of caching issues found by running all tests with statement caching turned on. The cache system now has a more conservative approach where any subclass of a SQL element will by default invalidate the cache key unless it adds the flag inherit_cache=True at the class level, or if it implements its own caching. Add working caching to a few elements that were omitted previously; fix some caching implementations to suit lesser used edge cases such as json casts and array slices. Refine the way BaseCursorResult and CursorMetaData interact with caching; to suit cases like Alembic modifying table structures, don't cache the cursor metadata if it were created against a cursor.description using non-positional matching, e.g. "select *". if a table re-ordered its columns or added/removed, now that data is obsolete. Additionally we have to adapt the cursor metadata _keymap regardless of if we just processed cursor.description, because if we ran against a cached SQLCompiler we won't have the right columns in _keymap. Other refinements to how and when we do this adaption as some weird cases were exposed in the Postgresql dialect, a text() construct that names just one column that is not actually in the statement. Fixed that also as it looks like a cut-and-paste artifact that doesn't actually affect anything. Various issues with re-use of compiled result maps and cursor metadata in conjunction with tables being changed, such as change in order of columns. mappers can be cleared but the class remains, meaning a mapper has to use itself as the cache key not the class. lots of bound parameter / literal issues, due to Alembic creating a straight subclass of bindparam that renders inline directly. While we can update Alembic to not do this, we have to assume other people might be doing this, so bindparam() implements the inherit_cache=True logic as well that was a bit involved. turn on cache stats in logging. Includes a fix to subqueryloader which moves all setup to the create_row_processor() phase and elminates any storage within the compiled context. This includes some changes to create_row_processor() signature and a revising of the technique used to determine if the loader can participate in polymorphic queries, which is also applied to selectinloading. DML update.values() and ordered_values() now coerces the keys as we have tests that pass an arbitrary class here which only includes __clause_element__(), so the key can't be cached unless it is coerced. this in turn changed how composite attributes support bulk update to use the standard approach of ClauseElement with annotations that are parsed in the ORM context. memory profiling successfully caught that the Session from Query was getting passed into _statement_20() so that was a big win for that test suite. Apparently Compiler had .execute() and .scalar() methods stuck on it, these date back to version 0.4 and there was a single test in the PostgreSQL dialect tests that exercised it for no apparent reason. Removed these methods as well as the concept of a Compiler holding onto a "bind". Fixes: #5386 Change-Id: I990b43aab96b42665af1b2187ad6020bee778784
* Improve rendering of core statements w/ ORM elementsMike Bayer2020-05-311-1/+1
| | | | | | | | | | | | | | | | | | | | This patch contains a variety of ORM and expression layer tweaks to support ORM constructs in select() statements, without the 1.3.x requiremnt in Query that a full _compile_context() + new select() is needed in order to get a working statement object. Includes such tweaks as the ability to implement aliased class of an aliased class, as we are looking to fully support ACs against subqueries, as well as the ability to access anonymously-labeled ColumnProperty expressions within subqueries by naming the ".key" of the label after the property key. Some tuning to query.join() as well as ORMJoin internals to allow things to work more smoothly. Change-Id: Id810f485c5f7ed971529489b84694e02a3356d6d
* Remove loader option cycleMike Bayer2020-05-291-4/+0
| | | | | | | | removed a reference cycle set up by loader options due to the attribute dictionary containing Load objects that reference that dictionary. Change-Id: Ie3159a084f819ae44ca4992b0dbe094fb69b2fa7
* callcount reductions and refinement for cached queriesMike Bayer2020-05-281-73/+116
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit includes that we've removed the "_orm_query" attribute from compile state as well as query context. The attribute created reference cycles and also added method call overhead. As part of this change, the interface for ORMExecuteState changes a bit, as well as the interface for the horizontal sharding extension which now deprecates the "query_chooser" callable in favor of "execute_chooser", which receives the contextual object. This will also work more nicely when we implement the new execution path for bulk updates and deletes. Pre-merge execution options for statement, connection, arguments all up front in Connection. that way they can be passed to the before_execute / after_execute events, and the ExecutionContext doesn't have to merge as second time. Core execute is pretty close to 1.3 now. baked wasn't using the new one()/first()/one_or_none() methods, fixed that. Convert non-buffered cursor strategy to be a stateless singleton. inline all the paths by which the strategy gets chosen, oracle and SQL Server dialects make use of the already-invoked post_exec() hook to establish the alternate strategies, and this is actually much nicer than it was before. Add caching to mapper instance processor for getters. Identified a reference cycle per query that was showing up as a lot of gc cleanup, fixed that. After all that, performance not budging much. Even test_baked_query now runs with significantly fewer function calls than 1.3, still 40% slower. Basically something about the new patterns just makes this slower and while I've walked a whole bunch of them back, it hardly makes a dent. that said, the performance issues are relatively small, in the 20-40% time increase range, and the new caching feature does provide for regular ORM and Core queries that are cached, and they are faster than non-cached. Change-Id: I7b0b0d8ca550c05f79e82f75cd8eff0bbfade053
* Revert 903b18828461bb8cb8dca4acc56809b3df2b14d5Mike Bayer2020-05-251-80/+44
| | | | | | This was accidentally pushed just now. Change-Id: I4da4151c4a81e5cf72146f8dcab3537301ccaae9
* Small callcount reductions and refinement for cached queriesMike Bayer2020-05-251-44/+80
| | | | | | | | | | | | | | | baked wasn't using the new one()/first()/one_or_none() methods, fixed that. loading._instance_processor() can skip setting up the quick populators every time because it can cache the getters. Callcounts have gone below what 1.3 does for the test_baked_query performance suite, however runtime for continued inexplicable reasons has not :(. still suspecting the result tuples but this seems so hard to believe. Change-Id: Ifbca04834d27350e0fa82cb8512e66112abc8729
* Convert execution to move through SessionMike Bayer2020-05-251-40/+191
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch replaces the ORM execution flow with a single pathway through Session.execute() for all queries, including Core and ORM. Currently included is full support for ORM Query, Query.from_statement(), select(), as well as the baked query and horizontal shard systems. Initial changes have also been made to the dogpile caching example, which like baked query makes use of a new ORM-specific execution hook that replaces the use of both QueryEvents.before_compile() as well as Query._execute_and_instances() as the central ORM interception hooks. select() and Query() constructs alike can be passed to Session.execute() where they will return ORM results in a Results object. This API is currently used internally by Query. Full support for Session.execute()->results to behave in a fully 2.0 fashion will be in later changesets. bulk update/delete with ORM support will also be delivered via the update() and delete() constructs, however these have not yet been adapted to the new system and may follow in a subsequent update. Performance is also beginning to lag as of this commit and some previous ones. It is hoped that a few central functions such as the coercions functions can be rewritten in C to re-gain performance. Additionally, query caching is now available and some subsequent patches will attempt to cache more of the per-execution work from the ORM layer, e.g. column getters and adapters. This patch also contains initial "turn on" of the caching system enginewide via the query_cache_size parameter to create_engine(). Still defaulting at zero for "no caching". The caching system still needs adjustments in order to gain adequate performance. Change-Id: I047a7ebb26aa85dc01f6789fac2bff561dcd555d
* Unify Query and select() , move all processing to compile phaseMike Bayer2020-05-241-48/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | Convert Query to do virtually all compile state computation in the _compile_context() phase, and organize it all such that a plain select() construct may also be used as the source of information in order to generate ORM query state. This makes it such that Query is not needed except for its additional methods like from_self() which are all to be deprecated. The construction of ORM state will occur beyond the caching boundary when the new execution model is integrated. future select() gains a working join() and filter_by() method. as we continue to rebase and merge each commit in the steps, callcounts continue to bump around. will have to look at the final result when it's all in. References: #5159 References: #4705 References: #4639 References: #4871 References: #5010 Change-Id: I19e05b3424b07114cce6c439b05198ac47f7ac10
* Performance fixes for new result setMike Bayer2020-05-211-4/+12
| | | | | | | | | | | A few small mistakes led to huge callcounts. Additionally, the warn-on-get behavior which is attempting to warn for deprecated access in SQLAlchemy 2.0 is very expensive; it's not clear if its feasible to have this warning or to somehow alter how it works. Fixes: #5340 Change-Id: I73bdd2d7b6f1b25cc0222accabd585cf761a5af4
* Integrate new Result into ORM queryMike Bayer2020-05-021-38/+62
| | | | | | | | | | | | | | | | | | | | | | | | The next step in the 2.0 ORM changes is to have the ORM integrate with the new Result object fully. this patch uses Result to represent ORM objects rather than lists. public API to get at this Result is not added yet. dogpile.cache and horizontal sharding recipe/extensions have small adjustments to accommodate this change. Callcounts have fluctuated, some slightly better and some slightly worse. A few have gone up by a bit, however as the codebase is still in flux it is anticipated there will be some performance gains later on as ORM fetching is refined to no longer need to accommodate for extensive aliasing. The addition of caching will then change the entire story. References: #5087 References: #4395 Change-Id: If1a23824ffb77d8d58cf2338cf35dd6b5963b17f
* Propose Result as immediate replacement for ResultProxyMike Bayer2020-05-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As progress is made on the _future.Result, including breaking it out such that DBAPI behaviors are local to specific implementations, it becomes apparent that the Result object is a functional superset of ResultProxy and that basic operations like fetchone(), fetchall(), and fetchmany() behave pretty much exactly the same way on the new object. Reorganize things so that ResultProxy is now referred to as LegacyCursorResult, which subclasses CursorResult that represents the DBAPI-cursor version of Result, making use of a multiple inheritance pattern so that the functionality of Result is also available in non-DBAPI contexts, as will be necessary for some ORM patterns. Additionally propose the composition system for Result that will form the basis for ORM-alternative result systems such as horizontal sharding and dogpile cache. As ORM results will soon be coming directly from instances of Result, these extensions will instead build their own ResultFetchStrategies that perform the special steps to create composed or cached result sets. Also considering at the moment not emitting deprecation warnings for fetchXYZ() methods; the immediate issue is Keystone tests are calling upon it, but as the implementations here are proving to be not in any kind of conflict with how Result works, there's not too much issue leaving them around and deprecating at some later point. References: #5087 References: #4395 Fixes: #4959 Change-Id: I8091919d45421e3f53029b8660427f844fee0228
* Run search and replace of symbolic module namesMike Bayer2020-04-141-1/+1
| | | | | | | | Replaces a wide array of Sphinx-relative doc references with an abbreviated absolute form now supported by zzzeeksphinx. Change-Id: I94bffcc3f37885ffdde6238767224296339698a2
* Run autoflush for column attribute load operationsMike Bayer2020-04-031-2/+14
| | | | | | | | | | | | | | | | | The "autoflush" behavior of :class:`.Query` will now trigger for nearly all ORM level attribute load operations, including when a deferred column is loaded as well as when an expired column is loaded. Previously, autoflush on load of expired or unloaded attributes was limited to relationship-bound attributes only. However, this led to the issue where column-based attributes that also depended on other rows, or even other columns in the same row, in order to express the correct value, would show an effectively stale value when accessed as there could be pending changes in the session left to be flushed. Autoflush is now disabled only in some cases where attributes are being unexpired in the context of a history operation. Fixes: #5226 Change-Id: Ibd965b30918cd273ae020411a704bf2bb1891f59
* Test instance for matching class hierarchy on get_from_identityMike Bayer2020-03-221-1/+4
| | | | | | | | | | | Fixed issue where a lazyload that uses session-local "get" against a target many-to-one relationship where an object with the correct primary key is present, however it's an instance of a sibling class, does not correctly return None as is the case when the lazy loader actually emits a load for that row. Fixes: #5210 Change-Id: I89f9946cfeba61d89a272435f76a5a082b1da30c
* Simplified module pre-loading strategy and made it linter friendlyFederico Caselli2020-03-071-2/+3
| | | | | | | | | | | | | | | | | Introduced a modules registry to register modules that should be lazily loaded in the package init. This ensures that they are in the system module cache, avoiding potential thread safety issues as when importing them directly in the function that uses them. The module registry is used to obtain these modules directly, ensuring that the all the lazily loaded modules are resolved at the proper time This replaces dependency_for decorator and the dependencies decorator logic, removing the need to pass the resolved modules as arguments of the decodated functions and removes possible errors caused by linters. Fixes: #4689 Fixes: #4656 Change-Id: I2e291eba4297867fc0ddb5d875b9f7af34751d01
* Ensure all nested exception throws have a causeMike Bayer2020-03-021-3/+3
| | | | | | | | | | | | | | | Applied an explicit "cause" to most if not all internally raised exceptions that are raised from within an internal exception catch, to avoid misleading stacktraces that suggest an error within the handling of an exception. While it would be preferable to suppress the internally caught exception in the way that the ``__suppress_context__`` attribute would, there does not as yet seem to be a way to do this without suppressing an enclosing user constructed context, so for now it exposes the internally caught exception as the cause so that full information about the context of the error is maintained. Fixes: #4849 Change-Id: I55a86b29023675d9e5e49bc7edc5a2dc0bcd4751
* Result initial introductionMike Bayer2020-02-211-22/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This builds on cc718cccc0bf8a01abdf4068c7ea4f3 which moved RowProxy to Row, allowing Row to be more like a named tuple. - KeyedTuple in ORM is replaced with Row - ResultSetMetaData broken out into "simple" and "cursor" versions for ORM and Core, as well as LegacyCursor version. - Row now has _mapping attribute that supplies full mapping behavior. Row and SimpleRow both have named tuple behavior otherwise. LegacyRow has some mapping features on the tuple which emit deprecation warnings (e.g. keys(), values(), etc). the biggest change for mapping->tuple is the behavior of __contains__ which moves from testing of "key in row" to "value in row". - ResultProxy breaks into ResultProxy and FutureResult (interim), the latter has the newer APIs. Made available to dialects using execution options. - internal reflection methods and most tests move off of implicit Row mapping behavior and move to row._mapping, result.mappings() method using future result - a new strategy system for cursor handling replaces the various subclasses of RowProxy - some execution context adjustments. We will leave EC in but refined things like get_result_proxy() and out parameter handling. Dialects for 1.4 will need to adjust from get_result_proxy() to get_result_cursor_strategy(), if they are using this method - out parameter handling now accommodated by get_out_parameter_values() EC method. Oracle changes for this. external dialect for DB2 for example will also need to adjust for this. - deprecate case_insensitive flag for engine / result, this feature is not used mapping-methods on Row are deprecated, and replaced with Row._mapping.<meth>, including: row.keys() -> use row._mapping.keys() row.items() -> use row._mapping.items() row.values() -> use row._mapping.values() key in row -> use key in row._mapping int in row -> use int < len(row) Fixes: #4710 Fixes: #4878 Change-Id: Ieb9085e9bcff564359095b754da9ae0af55679f0
* Merge "Warn for runid changing in load events; add restore_load_context flag"mike bayer2020-01-311-1/+29
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| * Warn for runid changing in load events; add restore_load_context flagMike Bayer2020-01-311-1/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Added a new flag :paramref:`.InstanceEvents.restore_load_context` and :paramref:`.SessionEvents.restore_load_context` which apply to the :meth:`.InstanceEvents.load`, :meth:`.InstanceEvents.refresh`, and :meth:`.SessionEvents.loaded_as_persistent` events, which when set will restore the "load context" of the object after the event hook has been called. This ensures that the object remains within the "loader context" of the load operation that is already ongoing, rather than the object being transferred to a new load context due to refresh operations which may have occurred in the event. A warning is now emitted when this condition occurs, which recommends use of the flag to resolve this case. The flag is "opt-in" so that there is no risk introduced to existing applications. The change additionally adds support for the ``raw=True`` flag to session lifecycle events. Fixes: #5129 Change-Id: I2912f48ac8c5636297d63ed383454930e8e9a6a3
* | Raise for unexpected polymorphic identityMike Bayer2020-01-291-7/+33
|/ | | | | | | | | | | | | | | | | A query that is against an mapped inheritance subclass which also uses :meth:`.Query.select_entity_from` or a similar technique in order to provide an existing subquery to SELECT from, will now raise an error if the given subquery returns entities that do not correspond to the given subclass, that is, they are sibling or superclasses in the same hierarchy. Previously, these would be returned without error. Additionally, if the inheritance mapping is a single-inheritance mapping, the given subquery must apply the appropriate filtering against the polymorphic discriminator column in order to avoid this error; previously, the :class:`.Query` would add this criteria to the outside query however this interferes with some kinds of query that return other kinds of entities as well. Fixes: #5122 Change-Id: I60cf8c1300d5bb279ad99f0f01fefe7e008a159b
* happy new yearMike Bayer2020-01-011-1/+1
| | | | Change-Id: I08440dc25e40ea1ccea1778f6ee9e28a00808235
* Correctly interpret None passed to query.get(); warn for empty PK valueslizraeli2019-10-281-0/+6
| | | | | | | | | | | | | | | | | A warning is emitted if a primary key value is passed to :meth:`.Query.get` that consists of None for all primary key column positions. Previously, passing a single None outside of a tuple would raise a ``TypeError`` and passing a composite None (tuple of None values) would silently pass through. The fix now coerces the single None into a tuple where it is handled consistently with the other None conditions. Thanks to Lev Izraelit for the help with this. Fixes #4915 Closes: #4917 Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/4917 Pull-request-sha: b388343c7cabeecf8c779689b78e638c23f9af40 Change-Id: Ibc6c27ccf50dfd4adbf15b6dbd393115c30d44fb
* Add public accessor `is_single_entity` to QueryPatrick Hayes2019-10-271-5/+1
| | | | | | | | | | | | | | | | | Added accessor :attr:`.Query.is_single_entity` to :class:`.Query`, which will indicate if the results returned by this :class:`.Query` will be a list of ORM entities, or a tuple of entities or column expressions. SQLAlchemy hopes to improve upon the behavior of single entity / tuples in future releases such that the behavior would be explicit up front, however this attribute should be helpful with the current behavior. Pull request courtesy Patrick Hayes. Fixes: #4934 Closes: #4935 Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/4935 Pull-request-sha: 98f72b40a896761a65b048cc3722ff2dac4cf2b1 Change-Id: If5db5db3ea46a93406d76ef90b5b588149ba2986
* Implement raiseload for deferred columnsMike Bayer2019-10-161-0/+3
| | | | | | | | | | | | | | | | | | | | | Added "raiseload" feature for ORM mapped columns. As part of this change, the behavior of "deferred" is now more strict; an attribute that is set up as "deferred" at the mapper level no longer participates in an "unexpire" operation; that is, when an unexpire loads all the expired columns of an object which are not themselves in a deferred group, those which are mapper-level deferred will never be loaded. Deferral options set at query time should always be reset by an expiration operation. Renames deferred_scalar_loader to expired_attribute_loader Unfortunately we can't have raiseload() do this because it would break existing wildcard behavior. Fixes: #4826 Change-Id: I30d9a30236e0b69134e4094fb7c1ad2267f089d1
* Merge "Run row value processors up front"mike bayer2019-10-011-11/+10
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| * Run row value processors up frontMike Bayer2019-10-011-11/+10
| | | | | | | | | | | | | | | | | | | | | | | | as part of a larger series of changes to generalize row-tuples, RowProxy becomes plain Row and is no longer a "proxy"; the DBAPI row is now copied directly into the Row when constructed, result handling occurs at once. Subsequent changes will break out Row into a new version that behaves fully a tuple. Change-Id: I2ffa156afce5d21c38f28e54c3a531f361345dd5
* | Cancel polymorphic loading in optimized getMike Bayer2019-10-011-3/+4
|/ | | | | | | | | | | | | Since optimized_get for inheriting mappers writes a simple SELECT, we need to cancel out any with_polymorphic selectables that interfere with simple column lookup. While adaptation is another option, just removing the with_polymorphic is much simpler. The issue is not noticeable unless the ResultProxy is not allowing "key fallback" column lookups, which will be the case when this behavior is deprecated. Fixes: #4718 Change-Id: I8fa2f5c0434b6a681813a92ac71fe12712f5d634
* Raise for NULL discriminator and pk is presentMike Bayer2019-09-031-1/+21
| | | | | | | | | An exception is now raised if the ORM loads a row for a polymorphic instance that has a primary key but the discriminator column is NULL, as discriminator columns should not be null. Fixes: #4836 Change-Id: Ice1a853a7dd7687c58079b9933f145b90d314236
* Run eager loaders on unexpireMike Bayer2019-08-231-0/+4
| | | | | | | | | | | | Eager loaders, such as joined loading, SELECT IN loading, etc., when configured on a mapper or via query options will now be invoked during the refresh on an expired object; in the case of selectinload and subqueryload, since the additional load is for a single object only, the "immediateload" scheme is used in these cases which resembles the single-parent query emitted by lazy loading. Change-Id: I7ca2c77bff58dc21015d60093a88c387937376b2 Fixes: #1763
* happy new yearMike Bayer2019-01-111-1/+1
| | | | Change-Id: I6a71f4924d046cf306961c58dffccf21e9c03911
* Post black reformattingMike Bayer2019-01-061-8/+11
| | | | | | | | | | | | | Applied on top of a pure run of black -l 79 in I7eda77fed3d8e73df84b3651fd6cfcfe858d4dc9, this set of changes resolves all remaining flake8 conditions for those codes we have enabled in setup.cfg. Included are resolutions for all remaining flake8 issues including shadowed builtins, long lines, import order, unused imports, duplicate imports, and docstring issues. Change-Id: I4f72d3ba1380dd601610ff80b8fb06a2aff8b0fe
* Run black -l 79 against all source filesMike Bayer2019-01-061-140/+241
| | | | | | | | | | | | | | This is a straight reformat run using black as is, with no edits applied at all. The black run will format code consistently, however in some cases that are prevalent in SQLAlchemy code it produces too-long lines. The too-long lines will be resolved in the following commit that will resolve all remaining flake8 issues including shadowed builtins, long lines, import order, unused imports, duplicate imports, and docstring issues. Change-Id: I7eda77fed3d8e73df84b3651fd6cfcfe858d4dc9
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