summaryrefslogtreecommitdiff
path: root/lib/sqlalchemy/engine/result.py
Commit message (Collapse)AuthorAgeFilesLines
* tutorial 2.0 WIPreview/mike_bayer/tutorial20Mike Bayer2020-10-311-0/+4
| | | | | | | | | | | | | | Add SelectBase.exists() method as it seems strange this is not available already. The Exists construct itself does not provide full SELECT-building capabilities so it makes sense this should be used more like a scalar_subquery. Make sure stream_results is getting set up when yield_per is used, for 2.0 style statements as well. this was hardcoded inside of Query.yield_per() and is now moved to take place within QueryContext. Change-Id: Icafcd4fd9b708772343d56edf40995c9e8f835d6
* Improve some documentationsFederico Caselli2020-09-291-33/+26
| | | | Change-Id: Ibcb0da3166b94aa58fa92d544c3e5cf75844546e
* upgrade to black 20.8b1Mike Bayer2020-09-281-7/+13
| | | | | | | 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 Bayer2020-09-211-1/+4
| | | | | | | | | | | | | | | | | | | | | | 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
* Ensure cursor is closed for scalar() if make_row failsMike Bayer2020-09-121-8/+16
| | | | | | | | | As we have some tests that are against enums which can raise on fetch, if we call scalar() and it fails, we need to close the cursor. mariadb segfaults etc. seem to have been caused by this. Change-Id: I8261f6fe7f972ae2d8702650440fd8d71e9bce53
* make URL immutableMike Bayer2020-08-251-1/+1
| | | | | | | | | | | | | | it's not really correct that URL is mutable and doesn't do any argument checking. propose replacing it with an immutable named tuple with rich copy-and-mutate methods. At the moment this makes a hard change to the CreateEnginePlugin docs that previously recommended url.query.pop(). I can't find any plugins on github other than my own that are using this feature, so see if we can just make a hard change on this one. Fixes: #5526 Change-Id: I28a0a471d80792fa8c28f4fa573d6352966a4a79
* Implement rudimentary asyncio support w/ asyncpgMike Bayer2020-08-131-33/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Break scalars() and mappings() into separate objectsMike Bayer2020-08-121-463/+780
| | | | | | | | | | | | The issue of Result.fetchXXX() methods returning Row objects unless filtering is applied will not provide a clear enough API story when type annotations are applied, so break out scalars/mappings into separate wrapper objects. this makes some things more intuitive and other things a little more bumpy. however the return type story is now clearer. Fixes: #5503 Change-Id: I629a061823179680dc0723559183859a67ea4db1
* Documentation updates for 1.4Mike Bayer2020-08-051-2/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 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 remaining ORM APIs to support 2.0 styleMike Bayer2020-07-111-1/+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
* introduce deferred lambdasMike Bayer2020-07-031-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The coercions system allows us to add in lambdas as arguments to Core and ORM elements without changing them at all. By allowing the lambda to produce a deterministic cache key where we can also cheat and yank out literal parameters means we can move towards having 90% of "baked" functionality in a clearer way right in Core / ORM. As a second step, we can have whole statements inside the lambda, and can then add generation with __add__(), so then we have 100% of "baked" functionality with full support of ad-hoc literal values. Adds some more short_selects tests for the moment for comparison. Other tweaks inside cache key generation as we're trying to approach a certain level of performance such that we can remove the use of "baked" from the loader strategies. As we have not yet closed #4639, however the caching feature has been fully integrated as of b0cfa7379cf8513a821a3dbe3028c4965d9f85bd, we will also add complete caching documentation here and close that issue as well. Closes: #4639 Fixes: #5380 Change-Id: If91f61527236fd4d7ae3cad1f24c38be921c90ba
* 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
* Propose using RETURNING for bulk updates, deletesMike Bayer2020-06-231-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes several improvements in the area of bulk updates and deletes as well as the new session mechanics. RETURNING is now used for an UPDATE or DELETE statement emitted for a diaelct that supports "full returning" in order to satisfy the "fetch" strategy; this currently includes PostgreSQL and SQL Server. The Oracle dialect does not support RETURNING for more than one row, so a new dialect capability "full_returning" is added in addition to the existing "implicit_returning", indicating this dialect supports RETURNING for zero or more rows, not just a single identity row. The "fetch" strategy will gracefully degrade to the previous SELECT mechanics for dialects that do not support RETURNING. Additionally, the "fetch" strategy will attempt to use evaluation for the VALUES that were UPDATEd, rather than just expiring the updated attributes. Values should be evalutable in all cases where the value is not a SQL expression. The new approach also incurs some changes in the session.execute mechanics, where do_orm_execute() event handlers can now be chained to each return results; this is in turn used by the handler to detect on a per-bind basis if the fetch strategy needs to do a SELECT or if it can do RETURNING. A test suite is added to test_horizontal_shard that breaks up a single UPDATE or DELETE operation among multiple backends where some are SQLite and don't support RETURNING and others are PostgreSQL and do. The session event mechanics are corrected in terms of the "orm pre execute" hook, which now receives a flag "is_reentrant" so that the two ORM implementations for this can skip on their work if they are being called inside of ORMExecuteState.invoke(), where previously bulk update/delete were calling its SELECT a second time. In order for "fetch" to get the correct identity when called as pre-execute, it also requests the identity_token for each mapped instance which is now added as an optional capability of a SELECT for ORM columns. the identity_token that's placed by horizontal_sharding is now made available within each result row, so that even when fetching a merged result of plain rows we can tell which row belongs to which identity token. The evaluator that takes place within the ORM bulk update and delete for synchronize_session="evaluate" now supports the IN and NOT IN operators. Tuple IN is also supported. Fixes: #1653 Change-Id: I2292b56ae004b997cef0ba4d3fc350ae1dd5efc1
* Convert bulk update/delete to new execution modelMike Bayer2020-06-061-16/+69
| | | | | | | | | | | | | | | This reorganizes the BulkUD model in sqlalchemy.orm.persistence to be based on the CompileState concept and to allow plain update() / delete() to be passed to session.execute() where the ORM synchronize session logic will take place. Also gets "synchronize_session='fetch'" working with horizontal sharding. Adding a few more result.scalar_one() types of methods as scalar_one() seems like what is normally desired. Fixes: #5160 Change-Id: I8001ebdad089da34119eb459709731ba6c0ba975
* callcount reductions and refinement for cached queriesMike Bayer2020-05-281-68/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Convert execution to move through SessionMike Bayer2020-05-251-27/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* inline one_or_noneMike Bayer2020-05-241-20/+56
| | | | | | | Remove a bunch of unnecessary functions for this case. add test coverage to ensure uniqueness logic works. Change-Id: I2e6232c5667a3277b0ec8d7e47085a267f23d75f
* Avoid proxy functions in row functionsFederico Caselli2020-05-231-8/+12
| | | | | | | | | | | This streamlines a bit for non-C implementations, however also adds and tests behavioral contracts that mappings should not allow integer or slice access and should behave like a Python mapping in that it raises KeyError for an integer and TypeError for a slice. Py3/Py2/C/noC :) References: #5340 Change-Id: Id3cef452dc8a526b8371c90c5ca2bbb240b25c26
* Performance fixes for new result setMike Bayer2020-05-211-26/+77
| | | | | | | | | | | 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
* Documentation updates for ResultProxy -> ResultMike Bayer2020-05-011-2/+62
| | | | | | | | | This is based off of I8091919d45421e3f53029b8660427f844fee0228 and includes all documentation-only changes as a separate merge, once the parent is merged. Change-Id: I711adea23df0f9f0b1fe7c76210bd2de6d31842d
* Propose Result as immediate replacement for ResultProxyMike Bayer2020-05-011-1499/+799
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Create initial 2.0 engine implementationMike Bayer2020-04-161-0/+4
| | | | | | | | | | | | | | | | | | | Implemented the SQLAlchemy 2 :func:`.future.create_engine` function which is used for forwards compatibility with SQLAlchemy 2. This engine features always-transactional behavior with autobegin. Allow execution options per statement execution. This includes that the before_execute() and after_execute() events now accept an additional dictionary with these options, empty if not passed; a legacy event decorator is added for backwards compatibility which now also emits a deprecation warning. Add some basic tests for execution, transactions, and the new result object. Build out on a new testing fixture that swaps in the future engine completely to start with. Change-Id: I70e7338bb3f0ce22d2f702537d94bb249bd9fb0a Fixes: #4644
* Set up absolute references for create_engine and relatedMike Bayer2020-04-141-31/+41
| | | | | | | includes more replacements for create_engine(), Connection, disambiguation of Result from future/baked Change-Id: Icb60a79ee7a6c45ea9056c211ffd1be110da3b5e
* Run search and replace of symbolic module namesMike Bayer2020-04-141-7/+10
| | | | | | | | Replaces a wide array of Sphinx-relative doc references with an abbreviated absolute form now supported by zzzeeksphinx. Change-Id: I94bffcc3f37885ffdde6238767224296339698a2
* Enable zzzeeksphinx module prefixesMike Bayer2020-04-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | zzzeeksphinx 1.1.2 in git can now convert short prefix names in a configured lookup to fully qualified module names, so that we can have succinct and portable pyrefs that still resolve absolutely. It also includes a formatter that will format all pyrefs in a fully consistent way regardless of the package path, by unconditionally removing all package tokens but always leaving class names in place including for methods, which means we no longer have to deal with tildes in pyrefs. The most immediate goal of the absolute prefixes is that we have lots of "ambiguous" names that appear in muliple places, like select(), ARRAY, ENUM etc. With the incoming future packages there is going to be lots of name overlap so it is necessary that all names eventually use absolute package paths when Sphinx receives them. In multiple stages, pyrefs will be converted using the zzzeeksphinx tools/fix_xrefs.py tool so that doclinks can be made absolute using symbolic prefixes. For this review, the actual search and replace of symbols is not performed, instead some general cleanup to prepare the docs as well as a lookup file used by the tool to do the conversion. this relatively small patch will be backported with appropriate changes to 1.3, 1.2, 1.1 and the tool can then be run on each branch individually. We are shooting for almost no warnings at all for master (still a handful I can't figure out which don't seem to have any impact) , very few for 1.3, and for 1.2 / 1.1 we hope for a significant reduction in warnings. Overall for all versions pyrefs should always point to the correct target, if they are in fact hyperlinked. it's better for a ref to go nowhere and be plain text than go to the wrong thing. Right now, hundreds of API links are pointing to the wrong thing as they are ambiguous names such as refresh(), insert(), update(), select(), join(), JSON etc. and Sphinx sends these all to essesntially random destinations among as many as five or six possible choices per symbol. A shorthand system that allows us to use absolute refs without having to type out a full blown absoulte module is the only way this is going to work, and we should ultimately seek to abandon any use of prefix dot for lookups. Everything should be on an underscore token so at the very least the module spaces can be reorganized without having to search and replace the entire documentation every time. Change-Id: I484a7329034af275fcdb322b62b6255dfeea9151
* Remove code deprecated before version 1.1Federico Caselli2020-04-091-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Remove deprecated method ``get_primary_keys` in the :class:`.Dialect` and :class:`.Inspector` classes. - Remove deprecated event ``dbapi_error`` and the method ``ConnectionEvents.dbapi_error`. - Remove support for deprecated engine URLs of the form ``postgres://``. - Remove deprecated dialect ``mysql+gaerdbms``. - Remove deprecated parameter ``quoting`` from :class:`.mysql.ENUM` and :class:`.mysql.SET` in the ``mysql`` dialect. - Remove deprecated function ``comparable_property``. and function ``comparable_using`` in the declarative extension. - Remove deprecated function ``compile_mappers``. - Remove deprecated method ``collection.linker``. - Remove deprecated method ``Session.prune`` and parameter ``Session.weak_identity_map``. This change also removes the class ``StrongInstanceDict``. - Remove deprecated parameter ``mapper.order_by``. - Remove deprecated parameter ``Session._enable_transaction_accounting`. - Remove deprecated parameter ``Session.is_modified.passive``. - Remove deprecated class ``Binary``. Please use :class:`.LargeBinary`. - Remove deprecated methods ``Compiled.compile``, ``ClauseElement.__and__`` and ``ClauseElement.__or__`` and attribute ``Over.func``. - Remove deprecated ``FromClause.count`` method. - Remove deprecated parameter ``Table.useexisting``. - Remove deprecated parameters ``text.bindparams`` and ``text.typemap``. - Remove boolean support for the ``passive`` parameter in ``get_history``. - Remove deprecated ``adapt_operator`` in ``UserDefinedType.Comparator``. Fixes: #4643 Change-Id: Idcd390c77bf7b0e9957907716993bdaa3f1a1763
* Try to measure new style caching in the ORM, take twoMike Bayer2020-04-011-1/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Supercedes: If78fbb557c6f2cae637799c3fec2cbc5ac248aaf Trying to see if by making the cache key memoized, we still can have the older "identity" form of caching which is the cheapest of all, at the same time as the newer "cache key each time" version that is not nearly as cheap; but still much cheaper than no caching at all. Also needed is a per-execution update of _keymap when we invoke from a cached select, so that Column objects that are anonymous or otherwise adapted will match up. this is analogous to the adaption of bound parameters from the cache key. Adds test coverage for the keymap / construct_params() changes related to caching. Also hones performance to a large extent for statement construction and cache key generation. Also includes a new memoized attribute approach that vastly simplifies the previous approach of "group_expirable_memoized_property" and finally integrates cleanly with _clone(), _generate(), etc. no more hardcoding of attributes is needed, as well as that most _reset_memoization() calls are no longer needed as the reset is inherent in a _generate() call; this also has dramatic performance improvements. Change-Id: I95c560ffcbfa30b26644999412fb6a385125f663
* Correct ambiguous func / class linksMike Bayer2020-03-251-1/+1
| | | | | | | | | :func:`.sql.expression.select`, :func:`.sql.expression.insert` and :class:`.sql.expression.Insert` were hitting many ambiguous symbol errors, due to future.select, as well as the PG/MySQL variants of Insert. Change-Id: Iac862bfc172a7f7f0cbba5353a83dc203bed376c
* Deprecate plain string in execute and introduce `exec_driver_sql`Federico Caselli2020-03-211-1/+1
| | | | | | | | | | | | | | | Execution of literal sql string is deprecated in the :meth:`.Connection.execute` and a warning is raised when used stating that it will be coerced to :func:`.text` in a future release. To execute a raw sql string the new connection method :meth:`.Connection.exec_driver_sql` was added, that will retain the previous behavior, passing the string to the DBAPI driver unchanged. Usage of scalar or tuple positional parameters in :meth:`.Connection.execute` is also deprecated. Fixes: #4848 Fixes: #5178 Change-Id: I2830181054327996d594f7f0d59c157d477c3aa9
* Ensure all nested exception throws have a causeMike Bayer2020-03-021-29/+41
| | | | | | | | | | | | | | | 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 Bayer2020-02-211-661/+741
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Improve ResultProxy/Row documentation before the API changeMike Bayer2020-02-131-38/+75
| | | | | | | | | | | | We'd like to merge Ieb9085e9bcff564359095b754da9ae0af55679f0, however the documentation in that change should be based off of more comprehensive documentation than what we have already. Add the notion of "row" to the tutorial and document all methods. This will also be backported at least to 1.3 in terms of RowProxy. Change-Id: I2173aecc86cf15c5a7c473b8f471639ee9082f84
* happy new yearMike Bayer2020-01-011-1/+1
| | | | Change-Id: I08440dc25e40ea1ccea1778f6ee9e28a00808235
* Fix rst for flake8-rst-docstrings-0.0.12Mike Bayer2019-11-221-1/+1
| | | | | | A few new formatting errors are caught by this version. Change-Id: I737b33267a00f400b7ba7696a03ddb07a4c95bc0
* Use simple growth scale with any max size for BufferedRowResultProxysumau2019-10-301-24/+9
| | | | | | | | | | | | | | | | | The maximum buffer size for the :class:`.BufferedRowResultProxy`, which is used by dialects such as PostgreSQL when ``stream_results=True``, can now be set to a number greater than 1000 and the buffer will grow to that size. Previously, the buffer would not go beyond 1000 even if the value were set larger. The growth of the buffer is also now based on a simple multiplying factor currently set to 5. Pull request courtesy Soumaya Mauthoor. Fixes: #4914 Closes: #4930 Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/4930 Pull-request-sha: 66841f56e967c784f7078a787cec5129462006c8 Change-Id: I6286220bd9d488027fadc444039421a410e19a19
* Add result map targeting for custom compiled, text objectsMike Bayer2019-10-071-31/+31
| | | | | | | | | | | | | | | | In order for text(), custom compiled objects, etc. to be usable by Query(), they are all targeted by object key in the result map. As we no longer want Query to implicitly label these, as well as that text() has no label feature, support adding entries to the result map that have no name, key, or type, only the object itself, and then ensure that the compiler sets up for positional targeting when this condition is detected. Allows for more flexible ORM query usage with custom expressions and text() while having less special logic in query itself. Fixes: #4887 Change-Id: Ie073da127d292d43cb132a2b31bc90af88bfe2fd
* Restore result map checkMike Bayer2019-10-071-1/+1
| | | | | | Was mistakenly removed just now in c4dcf3dda63bfd9254ac5864cc Change-Id: I84998b6c45cf6b84502eabb3166984dd02fb00d8
* Remove order_by in textual testMike Bayer2019-10-071-1/+1
| | | | | | Fixes for SQL server Change-Id: I089bb9d400fb1b0708340792c3840e44bffa37e4
* Deprecate textual column matching in RowMike Bayer2019-10-041-17/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Deprecate query.instances() without a context Deprecate string alias with contains_eager() Deprecated the behavior by which a :class:`.Column` can be used as the key in a result set row lookup, when that :class:`.Column` is not part of the SQL selectable that is being selected; that is, it is only matched on name. A deprecation warning is now emitted for this case. Various ORM use cases, such as those involving :func:`.text` constructs, have been improved so that this fallback logic is avoided in most cases. Calling the :meth:`.Query.instances` method without passing a :class:`.QueryContext` is deprecated. The original use case for this was that a :class:`.Query` could yield ORM objects when given only the entities to be selected as well as a DBAPI cursor object. However, for this to work correctly there is essential metadata that is passed from a SQLAlchemy :class:`.ResultProxy` that is derived from the mapped column expressions, which comes originally from the :class:`.QueryContext`. To retrieve ORM results from arbitrary SELECT statements, the :meth:`.Query.from_statement` method should be used. Note there is a small bump in test_zoomark because the column._label is being calculated for each of those columns within baseline_3_properties, as it is now part of the result map. This label can't be calculated when the column is attached to the table because it needs to have all the columns present to do this correctly. Another approach here would be to pre-load the _label before the test runs however the zoomark tests don't have an easy place for this to happen and it's not really worth it. Fixes: #4877 Fixes: #4719 Change-Id: I9bd29e72e6dce7c855651d69ba68d7383469acbc
* Run row value processors up frontMike Bayer2019-10-011-190/+248
| | | | | | | | | | | | 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
* SelectBase no longer a FromClauseMike Bayer2019-07-061-3/+3
| | | | | | | | | | | | | | | | | | | | As part of the SQLAlchemy 2.0 migration project, a conceptual change has been made to the role of the :class:`.SelectBase` class hierarchy, which is the root of all "SELECT" statement constructs, in that they no longer serve directly as FROM clauses, that is, they no longer subclass :class:`.FromClause`. For end users, the change mostly means that any placement of a :func:`.select` construct in the FROM clause of another :func:`.select` requires first that it be wrapped in a subquery first, which historically is through the use of the :meth:`.SelectBase.alias` method, and is now also available through the use of :meth:`.SelectBase.subquery`. This was usually a requirement in any case since several databases don't accept unnamed SELECT subqueries in their FROM clause in any case. See the documentation in this change for lots more detail. Fixes: #4617 Change-Id: I0f6174ee24b9a1a4529168e52e855e12abd60667
* Enable F841Mike Bayer2019-06-201-2/+0
| | | | | | | | | | | This is a very useful assertion which prevents unused variables from being set up allows code to be more readable and sometimes even more efficient. test suites seem to be where the most problems are and there do not seem to be documentation examples that are using this, or at least the linter is not taking effect within rst blocks. Change-Id: I2b3341d8dd14da34879d8425838e66a4b9f8e27d
* Implement new ClauseElement role and coercion systemMike Bayer2019-05-181-1/+1
| | | | | | | | | | | | | | | | | | | | A major refactoring of all the functions handle all detection of Core argument types as well as perform coercions into a new class hierarchy based on "roles", each of which identify a syntactical location within a SQL statement. In contrast to the ClauseElement hierarchy that identifies "what" each object is syntactically, the SQLRole hierarchy identifies the "where does it go" of each object syntactically. From this we define a consistent type checking and coercion system that establishes well defined behviors. This is a breakout of the patch that is reorganizing select() constructs to no longer be in the FromClause hierarchy. Also includes a rename of as_scalar() into scalar_subquery(); deprecates automatic coercion to scalar_subquery(). Partially-fixes: #4617 Change-Id: I26f1e78898693c6b99ef7ea2f4e7dfd0e8e1a1bd
* Fix many spell glitchesLele Gaifax2019-01-251-2/+2
| | | | | | | | | | | | This affects mostly docstrings, except in orm/events.py::dispose_collection() where one parameter gets renamed: given that the method is empty, it seemed reasonable to me to fix that too. Closes: #4440 Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/4440 Pull-request-sha: 779ed75acb6142e1f1daac467b5b14134529bb4b Change-Id: Ic0553fe97853054b09c2453af76d96363de6eb0e
* Add deprecation warnings to all deprecated APIsMike Bayer2019-01-231-1/+0
| | | | | | | | | | | | | | | A large change throughout the library has ensured that all objects, parameters, and behaviors which have been noted as deprecated or legacy now emit ``DeprecationWarning`` warnings when invoked. As the Python 3 interpreter now defaults to displaying deprecation warnings, as well as that modern test suites based on tools like tox and pytest tend to display deprecation warnings, this change should make it easier to note what API features are obsolete. See the notes added to the changelog and migration notes for further details. Fixes: #4393 Change-Id: If0ea11a1fc24f9a8029352eeadfc49a7a54c0a1b
* happy new yearMike Bayer2019-01-111-1/+1
| | | | Change-Id: I6a71f4924d046cf306961c58dffccf21e9c03911
* Post black reformattingMike Bayer2019-01-061-10/+22
| | | | | | | | | | | | | 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 Bayer2019-01-061-155/+229
| | | | | | | | | | | | | | 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
* Import from collections.abcxtreak2018-09-271-2/+1
| | | | | | | | | | | | | | Fixed additional warnings generated by Python 3.7 due to changes in the organization of the Python ``collections`` and ``collections.abc`` packages. Previous ``collections`` warnings were fixed in version 1.2.11. Pull request courtesy xtreak. See I2d1c0ef97c8ecac7af152cc56263422a40faa6bb for the original collections.abc fixes. Fixes: #4339 Change-Id: Ia92d2461f20309fb33ea6c6f592f7d4e7e32ae7a Pull-request: https://github.com/zzzeek/sqlalchemy/pull/475
* happy new yearMike Bayer2018-01-121-1/+1
| | | | Change-Id: I3ef36bfd0cb0ba62b3123c8cf92370a43156cf8f