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* support bind expressions w/ expanding IN; apply to psycopg2Mike Bayer2021-10-151-3/+7
| | | | | | | | | | | | | | | | | | | | | | | Fixed issue where "expanding IN" would fail to function correctly with datatypes that use the :meth:`_types.TypeEngine.bind_expression` method, where the method would need to be applied to each element of the IN expression rather than the overall IN expression itself. Fixed issue where IN expressions against a series of array elements, as can be done with PostgreSQL, would fail to function correctly due to multiple issues within the "expanding IN" feature of SQLAlchemy Core that was standardized in version 1.4. The psycopg2 dialect now makes use of the :meth:`_types.TypeEngine.bind_expression` method with :class:`_types.ARRAY` to portably apply the correct casts to elements. The asyncpg dialect was not affected by this issue as it applies bind-level casts at the driver level rather than at the compiler level. as part of this commit the "bind translate" feature has been simplified and also applies to the names in the POSTCOMPILE tag to accommodate for brackets. Fixes: #7177 Change-Id: I08c703adb0a9bd6f5aeee5de3ff6f03cccdccdc5
* include setup_joins targets when scanning for FROM objects to cloneMike Bayer2021-09-201-0/+105
| | | | | | | | | | | | | | Fixed a two issues where combinations of ``select()`` and ``join()`` when adapted to form a copy of the element would not completely copy the state of all column objects associated with subqueries. A key problem this caused is that usage of the :meth:`_sql.ClauseElement.params` method (which should probably be moved into a legacy category as it is inefficient and error prone) would leave copies of the old :class:`_sql.BindParameter` objects around, leading to issues in correctly setting the parameters at execution time. Fixes: #7055 Change-Id: Ib822a978a99561b4402da3fb727b370f5c58210b
* reset key/name when TableValuedColumn is adaptedMike Bayer2021-07-161-0/+15
| | | | | | | | | | Fixed issue in new :meth:`_schema.Table.table_valued` method where the resulting :class:`_sql.TableValuedColumn` construct would not respond correctly to alias adaptation as is used throughout the ORM, such as for eager loading, polymorphic loading, etc. Fixes: #6775 Change-Id: I77cec4b6e1b1003f2b6be242b54ada8e4a435250
* Ensure alias traversal block works when adapt_from_selectables presentMike Bayer2021-07-141-2/+15
| | | | | | | | | | | | Fixed regression which appeared in version 1.4.3 due to :ticket:`6060` where rules that limit ORM adaptation of derived selectables interfered with other ORM-adaptation based cases, in this case when applying adaptations for a :func:`_orm.with_polymorphic` against a mapping which uses a :func:`_orm.column_property` which in turn makes use of a scalar select that includes a :func:`_orm.aliased` object of the mapped table. Fixes: #6762 Change-Id: Ice3dc34b97d12b59f044bdc0c5faaefcc4015227
* memoize current options and joins w with_entities/with_only_colsMike Bayer2021-06-171-0/+23
| | | | | | | | | | | | | | | | Fixed further regressions in the same area as that of :ticket:`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: #6503 Fixes: #6253 Change-Id: I211b2af98b0b20d1263fb15dc513884dcc5de6a4
* Fix adaption in AnnotatedLabel; repair needless expense in coercionMike Bayer2021-05-281-0/+28
| | | | | | | | | | | | | | | Fixed regression involving clause adaption of labeled ORM compound elements, such as single-table inheritance discriminator expressions with conditionals or CASE expressions, which could cause aliased expressions such as those used in ORM join / joinedload operations to not be adapted correctly, such as referring to the wrong table in the ON clause in a join. This change also improves a performance bump that was located within the process of invoking :meth:`_sql.Select.join` given an ORM attribute as a target. Fixes: #6550 Change-Id: I98906476f0cce6f41ea00b77c789baa818e9d167
* set bindparam.expanding in coercion againMike Bayer2021-05-101-0/+16
| | | | | | | | | | | | | | | | | Adjusted the logic added as part of :ticket:`6397` in 1.4.12 so that internal mutation of the :class:`.BindParameter` object occurs within the clause construction phase as it did before, rather than in the compilation phase. In the latter case, the mutation still produced side effects against the incoming construct and additionally could potentially interfere with other internal mutation routines. In order to solve the issue of the correct operator being present on the BindParameter.expand_op, we necessarily have to expand the BinaryExpression._negate() routine to flip the operator on the BindParameter also. Fixes: #6460 Change-Id: I1e53a9aeee4de4fc11af51d7593431532731561b
* Merge "Don't stringify unnamed column elements when proxying"mike bayer2021-04-171-2/+2
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| * Don't stringify unnamed column elements when proxyingMike Bayer2021-04-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Repaired and solidified issues regarding custom functions and other arbitrary expression constructs which within SQLAlchemy's column labeling mechanics would seek to use ``str(obj)`` to get a string representation to use as an anonymous column name in the ``.c`` collection of a subquery. This is a very legacy behavior that performs poorly and leads to lots of issues, so has been revised to no longer perform any compilation by establishing specific methods on :class:`.FunctionElement` to handle this case, as SQL functions are the only use case that it came into play. An effect of this behavior is that an unlabeled column expression with no derivable name will be given an arbitrary label starting with the prefix ``"_no_label"`` in the ``.c`` collection of a subquery; these were previously being represented either as the generic stringification of that expression, or as an internal symbol. This change seeks to make the concept of "anon name" more private and renames anon_label and anon_key_label to _anon_name_label and _anon_key_label. There's no end-user utility to these accessors and we need to be able to reorganize these as well. Fixes: #6256 Change-Id: Ie63c86b20ca45873affea78500388da94cf8bf94
* | Uniquify FROMs when traversing through selectMike Bayer2021-04-171-0/+38
|/ | | | | | | | | | | | | | | | | | Fixed a critical performance issue where the traversal of a :func:`_sql.select` construct would traverse a repetitive product of the represented FROM clauses as they were each referred towards by columns in the columns clause; for a series of nested subqueries with lots of columns this could cause a large delay and significant memory growth. This traversal is used by a wide variety of SQL and ORM functions, including by the ORM :class:`_orm.Session` when it's configured to have "table-per-bind", which while this is not a common use case, it seems to be what Flask-SQLAlchemy is hardcoded as using, so the issue impacts Flask-SQLAlchemy users. The traversal has been repaired to uniqify on FROM clauses which was effectively what would happen implicitly with the pre-1.4 architecture. Fixes: #6304 Change-Id: I43497e943db4065deab0bfc830fbb68c17b80a53
* Fix with_expression() cache leak; don't adapt singletonsMike Bayer2021-04-141-0/+71
| | | | | | | | | | | | | | | | | | | | Fixed a cache leak involving the :func:`_orm.with_expression` loader option, where the given SQL expression would not be correctly considered as part of the cache key. Additionally, fixed regression involving the corresponding :func:`_orm.query_expression` feature. While the bug technically exists in 1.3 as well, it was not exposed until 1.4. The "default expr" value of ``null()`` would be rendered when not needed, and additionally was also not adapted correctly when the ORM rewrites statements such as when using joined eager loading. The fix ensures "singleton" expressions like ``NULL`` and ``true`` aren't "adapted" to refer to columns in ORM statements, and additionally ensures that a :func:`_orm.query_expression` with no default expression doesn't render in the statement if a :func:`_orm.with_expression` isn't used. Fixes: #6259 Change-Id: I5a70bc12dadad125bbc4324b64048c8d4a18916c
* Ensure bindparam key escaping applied in all casesMike Bayer2021-04-121-1/+49
| | | | | | | | | | | Fixed regression where the :class:`_sql.BindParameter` object would not properly render for an IN expression (i.e. using the "post compile" feature in 1.4) if the object were copied from either an internal cloning operation, or from a pickle operation, and the parameter name contained spaces or other special characters. Fixes: #6249 Change-Id: Icd0d4096c8fa4eb1a1d4c20f8a96d8b1ae439f0a
* Adjust derivation rules for table vs. subquery against a joinMike Bayer2021-03-231-14/+101
| | | | | | | | | | | | | | | | | | | | | | | Fixed bug where ORM queries using a correlated subquery in conjunction with :func:`_orm.column_property` would fail to correlate correctly to an enclosing subquery or to a CTE when :meth:`_sql.Select.correlate_except` were used in the property to control correlation, in cases where the subquery contained the same selectables as ones within the correlated subquery that were intended to not be correlated. This is achieved by adding a limiting factor to ClauseAdapter which is to explicitly pass the selectables we will be adapting "from", which is then used by AliasedClass to limit "from" to the mappers represented by the AliasedClass. This did cause one test where an alias for a contains_eager() was missing to suddenly fail, and the test was corrected, however there may be some very edge cases like that one where the tighter criteria causes an existing use case that's relying on the more liberal aliasing to require modifications. Fixes: #6060 Change-Id: I8342042641886e1a220beafeb94fe45ea7aadb33
* Ensure ClauseAdapter treats FunctionElement as a ColumnElementMike Bayer2021-03-181-0/+34
| | | | | | | | | | Fixed regression where use of an unnamed SQL expression such as a SQL function would raise a column targeting error if the query itself were using joinedload for an entity and was also being wrapped in a subquery by the joinedload eager loading process. Fixes: #6086 Change-Id: I22cf4d6974685267c4f903bd7639be8271c6c1ef
* Replace with_labels() and apply_labels() in ORM/CoreGord Thompson2021-01-261-23/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* reinvent xdist hooks in terms of pytest fixturesMike Bayer2021-01-131-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: #5826 Fixes: #5827 Change-Id: Ib1d05cb8c7cf84f9a4bfd23df397dc23c9329bfe
* upgrade to black 20.8b1Mike Bayer2020-09-281-3/+7
| | | | | | | 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
* Add deprecation warning for .join().alias()Gord Thompson2020-09-281-1/+1
| | | | | | | | | The :meth:`_sql.Join.alias` method is deprecated and will be removed in SQLAlchemy 2.0. An explicit select + subquery, or aliasing of the inner tables, should be used instead. Fixes: #5010 Change-Id: Ic913afc31f0d70b0605f9a7af2742a0de1f9ad19
* Create a framework to allow all SQLALCHEMY_WARN_20 to passMike Bayer2020-09-161-7/+7
| | | | | | | | | | | | | | | | | | | | | As the test suite has widespread use of many patterns that are deprecated, enable SQLALCHEMY_WARN_20 globally for the test suite but then break the warnings filter out into a whole list of all the individual warnings we are looking for. this way individual changesets can target a specific class of warning, as many of these warnings will indivdidually affect dozens of files and potentially hundreds of lines of code. Many warnings are also resolved here as this patch started out that way. From this point forward there should be changesets that target a subset of the warnings at a time. For expediency, updates some migration 2.0 docs for ORM as well. Change-Id: I98b8defdf7c37b818b3824d02f7668e3f5f31c94
* Update select usage to use the new 1.4 formatFederico Caselli2020-09-081-58/+71
| | | | | | | | | | | | | | | | 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
* internal test framework files for standardization of is_not/not_in;jonathan vanasco2020-08-291-8/+8
| | | | | | this is safe for 1.3.x Change-Id: Icba38fdc20f5d8ac407383a4278ccb346e09af38
* Robustness for lambdas, lambda statementsMike Bayer2020-08-051-0/+84
| | | | | | | | | | | | | | | | | | | | 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
* Add future=True to create_engine/Session; unify select()Mike Bayer2020-07-081-106/+89
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Unify Query and select() , move all processing to compile phaseMike Bayer2020-05-241-0/+125
| | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Try to measure new style caching in the ORM, take twoMike Bayer2020-04-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Rework select(), CompoundSelect() in terms of CompileStateMike Bayer2020-03-101-18/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Continuation of I408e0b8be91fddd77cf279da97f55020871f75a9 - add an options() method to the base Generative construct. this will be where ORM options can go - Change Null, False_, True_ to be singletons, so that we aren't instantiating them and having to use isinstance. The previous issue with this was that they would produce dupe labels in SELECT statements. Apply the duplicate column logic, newly added in 1.4, to these objects as well as to non-apply-labels SELECT statements in general as a means of improving this. - create a revised system for generating ClauseList compilation constructs that simplfies up front creation to not actually use ClauseList; a simple tuple is rendered by the compiler using the same constrcution rules as what are used for ClauseList but without creating the actual object. Apply to Select, CompoundSelect, revise Update, Delete - Select, CompoundSelect get an initial CompileState implementation. All methods used only within compilation are moved here - refine update/insert/delete compile state to not require an outside boolean - refine and simplify Select._copy_internals - rework bind(), which is going away, to not use some of the internal traversal stuff - remove "autocommit", "for_update" parameters from Select, references #4643 - remove "autocommit" parameter from TextClause , references #4643 - add deprecation warnings for statement.execute(), engine.execute(), statement.scalar(), engine.scalar(). Fixes: #5193 Change-Id: I04ca0152b046fd42c5054ba10f37e43fc6e5a57b
* Decouple compiler state from DML objects; make cacheableMike Bayer2020-03-061-41/+100
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Targeting select / insert / update / delete, the goal is to minimize overhead of construction and generative methods so that only the raw arguments passed are handled. An interim stage that converts the raw state into more compiler-ready state is added, which is analogous to the ORM QueryContext which will also be rolled in to be a similar concept, as is currently being prototyped in I19e05b3424b07114cce6c439b05198ac47f7ac10. the ORM update/delete BulkUD concept is also going to be rolled onto this idea. So while the compiler-ready state object, here called DMLState, looks a little thin, it's the base of a bigger pattern that will allow for ORM functionality to embed itself directly into the compiler, execution context, and result set objects. This change targets the DML objects, primarily focused on the values() method which is the most complex process. The work done by values() is minimized as much as possible while still being able to create a cache key. Additional computation is then offloaded to a new object ValuesState that is handled by the compiler. Architecturally, a big change here is that insert.values() and update.values() will generate BindParameter objects for the values now, which are then carefully received by crud.py so that they generate the expected names. This is so that the values() portion of these constructs is cacheable. for the "multi-values" version of Insert, this is all skipped and the plan right now is that a multi-values insert is not worth caching (can always be revisited). Using the coercions system in values() also gets us nicer validation for free, we can remove the NotAClauseElement thing from schema, and we also now require scalar_subquery() is called for an insert/update that uses a SELECT as a column value, 1.x deprecation path is added. The traversal system is then applied to the DML objects including tests so that they have traversal, cloning, and cache key support. cloning is not a use case for DML however having it present allows better validation of the structure within the tests. Special per-dialect DML is explicitly not cacheable at the moment, more as a proof of concept that third party DML constructs can exist as gracefully not-cacheable rather than producing an incomplete cache key. A few selected performance improvements have been added as well, simplifying the immutabledict.union() method and adding a new SQLCompiler function that can generate delimeter-separated clauses like WHERE and ORDER BY without having to build a ClauseList object at all. The use of ClauseList will be removed from Select in an upcoming commit. Overall, ClaustList is unnecessary for internal use and only adds overhead to statement construction and will likely be removed as much as possible except for explcit use of conjunctions like and_() and or_(). Change-Id: I408e0b8be91fddd77cf279da97f55020871f75a9
* Create initial future package, RemovedIn20WarningMike Bayer2020-02-121-1/+1
| | | | | | | | | | | | | | | | | Reorganization of Select() is the first major element of the 2.0 restructuring. In order to start this we need to first create the new Select constructor and apply legacy elements to the old one. This in turn necessitates starting up the RemovedIn20Warning concept which itself need to refer to "sqlalchemy.future", so begin to establish this basic framework. Additionally, update the DML constructors with the newer no-keyword style. Remove the use of the "pending deprecation" and fix Query.add_column() deprecation which was not acting as deprecated. Fixes: #4845 Fixes: #4648 Change-Id: I0c7a22b2841a985e1c379a0bb6c94089aae6264c
* Test for short term reference cycles and resolve as many as possibleMike Bayer2019-12-301-2/+2
| | | | | | | | Added test support and repaired a wide variety of unnecessary reference cycles created for short-lived objects, mostly in the area of ORM queries. Fixes: #5056 Change-Id: Ifd93856eba550483f95f9ae63d49f36ab068b85a
* Add anonymizing context to cache keys, comparison; convert traversalMike Bayer2019-11-041-0/+2096
Created new visitor system called "internal traversal" that applies a data driven approach to the concept of a class that defines its own traversal steps, in contrast to the existing style of traversal now known as "external traversal" where the visitor class defines the traversal, i.e. the SQLCompiler. The internal traversal system now implements get_children(), _copy_internals(), compare() and _cache_key() for most Core elements. Core elements with special needs like Select still implement some of these methods directly however most of these methods are no longer explicitly implemented. The data-driven system is also applied to ORM elements that take part in SQL expressions so that these objects, like mappers, aliasedclass, query options, etc. can all participate in the cache key process. Still not considered is that this approach to defining traversibility will be used to create some kind of generic introspection system that works across Core / ORM. It's also not clear if real statement caching using the _cache_key() method is feasible, if it is shown that running _cache_key() is nearly as expensive as compiling in any case. Because it is data driven, it is more straightforward to optimize using inlined code, as is the case now, as well as potentially using C code to speed it up. In addition, the caching sytem now accommodates for anonymous name labels, which is essential so that constructs which have anonymous labels can be cacheable, that is, their position within a statement in relation to other anonymous names causes them to generate an integer counter relative to that construct which will be the same every time. Gathering of bound parameters from any cache key generation is also now required as there is no use case for a cache key that does not extract bound parameter values. Applies-to: #4639 Change-Id: I0660584def8627cad566719ee98d3be045db4b8d