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
Added "from linting" as a built-in feature to the SQL compiler. This allows the compiler to maintain graph of all the FROM clauses in a particular SELECT statement, linked by criteria in either the WHERE or in JOIN clauses that link these FROM clauses together. If any two FROM clauses have no path between them, a warning is emitted that the query may be producing a cartesian product. As the Core expression language as well as the ORM are built on an "implicit FROMs" model where a particular FROM clause is automatically added if any part of the query refers to it, it is easy for this to happen inadvertently and it is hoped that the new feature helps with this issue. The original recipe is from: https://github.com/sqlalchemy/sqlalchemy/wiki/FromLinter The linter is now enabled for all tests in the test suite as well. This has necessitated that a lot of the queries be adjusted to not include cartesian products. Part of the rationale for the linter to not be enabled for statement compilation only was to reduce the need for adjustment for the many test case statements throughout the test suite that are not real-world statements. This gerrit is adapted from Ib5946e57c9dba6da428c4d1dee6760b3e978dda0. Fixes: #4737 Change-Id: Ic91fd9774379f895d021c3ad564db6062299211c Closes: #4830 Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/4830 Pull-request-sha: f8a21aa6262d1bcc9ff0d11a2616e41fba97a47a
Change-Id: I08440dc25e40ea1ccea1778f6ee9e28a00808235
The "expanding IN" feature, which generates IN expressions at query execution time which are based on the particular parameters associated with the statement execution, is now used for all IN expressions made against lists of literal values. This allows IN expressions to be fully cacheable independently of the list of values being passed, and also includes support for empty lists. For any scenario where the IN expression contains non-literal SQL expressions, the old behavior of pre-rendering for each position in the IN is maintained. The change also completes support for expanding IN with tuples, where previously type-specific bind processors weren't taking effect. As part of this change, a more explicit separation between "literal execute" and "post compile" bound parameters is being made; as the "ansi bind rules" feature is rendering bound parameters inline, as we now support "postcompile" generically, these should be used here, however we have to render literal values at execution time even for "expanding" parameters. new test fixtures etc. are added to assert everything goes to the right place. Fixes: #4645 Change-Id: Iaa2b7bfbfaaf5b80799ee17c9b8507293cba6ed1
<!-- Provide a general summary of your proposed changes in the Title field above --> ### Description <!-- Describe your changes in detail --> Remove a redundant assignment in the engine creation file. ### Checklist <!-- go over following points. check them with an `x` if they do apply, (they turn into clickable checkboxes once the PR is submitted, so no need to do everything at once) --> This pull request is: - [x] A documentation / typographical error fix - Good to go, no issue or tests are needed - [ ] A short code fix - please include the issue number, and create an issue if none exists, which must include a complete example of the issue. one line code fixes without an issue and demonstration will not be accepted. - Please include: `Fixes: #<issue number>` in the commit message - please include tests. one line code fixes without tests will not be accepted. - [ ] A new feature implementation - please include the issue number, and create an issue if none exists, which must include a complete example of how the feature would look. - Please include: `Fixes: #<issue number>` in the commit message - please include tests. **Have a nice day!** Closes: #4944 Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/4944 Pull-request-sha: 4a0e6206f0ae5ff5350ecaa6f998bc3dc0c26cdd Change-Id: Ie491b071e3392334947d3b8ba84c7323c1b15b6e
Added new :func:`.create_engine` parameter :paramref:`.create_engine.max_identifier_length`. This overrides the dialect-coded "max identifier length" in order to accommodate for databases that have recently changed this length and the SQLAlchemy dialect has not yet been adjusted to detect for that version. This parameter interacts with the existing :paramref:`.create_engine.label_length` parameter in that it establishes the maximum (and default) value for anonymously generated labels. The Oracle dialect now emits a warning if Oracle version 12.2 or greater is used, and the :paramref:`.create_engine.max_identifier_length` parameter is not set. The version in this specific case defaults to that of the "compatibility" version set in the Oracle server configuration, not the actual server version. In version 1.4, the default max_identifier_length for 12.2 or greater will move to 128 characters. In order to maintain forwards compatibility, applications should set :paramref:`.create_engine.max_identifier_length` to 30 in order to maintain the same length behavior, or to 128 in order to test the upcoming behavior. This length determines among other things how generated constraint names are truncated for statements like ``CREATE CONSTRAINT`` and ``DROP CONSTRAINT``, which means a the new length may produce a name-mismatch against a name that was generated with the old length, impacting database migrations. Fixes: #4857 Change-Id: Ib62efb00c6180c375869029b57353d90385d7950
Added new parameter :paramref:`.create_engine.hide_parameters` which when set to True will cause SQL parameters to no longer be logged, nor rendered in the string representation of a :class:`.StatementError` object. Fixes: #4815 Change-Id: Ib87f868b6936cf6b42b192644e9d732ec24266c2
Fixed an issue whereby if the dialect "initialize" process which occurs on first connect would encounter an unexpected exception, the initialize process would fail to complete and then no longer attempt on subsequent connection attempts, leaving the dialect in an un-initialized, or partially initialized state, within the scope of parameters that need to be established based on inspection of a live connection. The "invoke once" logic in the event system has been reworked to accommodate for this occurrence using new, private API features that establish an "exec once" hook that will continue to allow the initializer to fire off on subsequent connections, until it completes without raising an exception. This does not impact the behavior of the existing ``once=True`` flag within the event system. Fixes: #4807 Change-Id: Iec32999b61b6af4b38b6719e0c2651454619078c
The dialects that support json are supposed to take arguments ``json_serializer`` and ``json_deserializer`` at the create_engine() level, however the SQLite dialect calls them ``_json_serilizer`` and ``_json_deserilalizer``. The names have been corrected, the old names are accepted with a change warning, and these parameters are now documented as :paramref:`.create_engine.json_serializer` and :paramref:`.create_engine.json_deserializer`. Fixes: #4798 Change-Id: I1dbfe439b421fe9bb7ff3594ef455af8156f8851
The "threadlocal" execution strategy, deprecated in 1.3, has been removed for 1.4, as well as the concept of "engine strategies" and the ``Engine.contextual_connect`` method. The "strategy='mock'" keyword argument is still accepted for now with a deprecation warning; use :func:`.create_mock_engine` instead for this use case. Fixes: #4632 Change-Id: I8a351f9fa1f7dfa2a56eec1cd2d1a4b9d65765a2 (cherry picked from commit b368c49b44c5716d93c7428ab22b6761c6ca7cf5)