Fixed issue where when constructing constraints from ORM-bound columns, primarily :class:`.ForeignKey` objects but also :class:`.UniqueConstraint`, :class:`.CheckConstraint` and others, the ORM-level :class:`.InstrumentedAttribute` is discarded entirely, and all ORM-level annotations from the columns are removed; this is so that the constraints are still fully pickleable without the ORM-level entities being pulled in. These annotations are not necessary to be present at the schema/metadata level. Fully implemented coercions for constraint columns within schema.py, including for FK referenced columns. Fixes: #5001 Change-Id: I895400dd979310be034085d207f096707c635909
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
Changed the ``repr()`` of the :class:`.quoted_name` construct to use regular string repr() under Python 3, rather than running it through "backslashreplace" escaping, which can be misleading. Modified the approach of "name normalization" for the Oracle and Firebird dialects, which converts from the UPPERCASE-as-case-insensitive convention of these dialects into lowercase-as-case-insensitive for SQLAlchemy, to not automatically apply the :class:`.quoted_name` construct to a name that matches itself under upper or lower case conversion, as is the case for many non-european characters. All names used within metadata structures are converted to :class:`.quoted_name` objects in any case; the change here would only affect the output of some inspection functions. Moved name normalize to be under default dialect, added test coverage in test/sql/test_quote.py Fixes: #4931 Change-Id: Ic121b20e07249824710a54423e321d94a425362f
Will backport the feature from part of 36e8fe4 / #4808 to 1.3. Fixes: #4933 Change-Id: Ide4069ff5cccd5ed83a5f314e5f21e51dfe08b7d
Fixed bug where a table that would have a column label overlap with a plain column name, such as "foo.id AS foo_id" vs. "foo.foo_id", would prematurely generate the ``._label`` attribute for a column before this overlap could be detected due to the use of the ``index=True`` or ``unique=True`` flag on the column in conjunction with the default naming convention of ``"column_0_label"``. This would then lead to failures when ``._label`` were used later to generate a bound parameter name, in particular those used by the ORM when generating the WHERE clause for an UPDATE statement. The issue has been fixed by using an alternate ``._label`` accessor for DDL generation that does not affect the state of the :class:`.Column`. The accessor also bypasses the key-deduplication step as it is not necessary for DDL, the naming is now consistently ``"<tablename>_<columnname>"`` without any subsequent numeric symbols when used in DDL. Fixes: #4911 Change-Id: Iabf5fd3250738d800d6e41a2a3a27a7ce2405e7d
As of #4753 we allow duplicate columns. This creates some new problems that there can be duplicate columns in a subquery which are then not addressible on the outside because they are ambiguous (Postgresql has this behavior at least). Additionally it creates situations where we are making an anon label of an anon label which is leaking into the query. New logic for generating anon labels handles this situation and also alters the .c collection of a subquery such that we are only getting the first column from the derived selectable that has that name, the subsequent ones have a new deduping label with two underscores and are not exposed in .c. The dedupe logic when rendering the columns will handle duplicate label names for different columns, vs. the same column repeated, as separate cases. Fixes: #4892 Change-Id: I929fbd8da14bcc239e0481c24bbd9b5ce826e8fa
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
Closes: #4861 Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/4861 Pull-request-sha: c7379d390752d0c10d6488872b163b06ee30d952 Change-Id: I223008f720fe64951e2a0bf95aab955ece22516b
Characters that interfere with "pyformat" or "named" formats in bound parameters, namely ``%, (, )`` and the space character, as well as a few other typically undesirable characters, are stripped early for a :func:`.bindparam` that is using an anonymized name, which is typically generated automatically from a named column which itself includes these characters in its name and does not use a ``.key``, so that they do not interfere either with the SQLAlchemy compiler's use of string formatting or with the driver-level parsing of the parameter, both of which could be demonstrated before the fix. The change only applies to anonymized parameter names that are generated and consumed internally, not end-user defined names, so the change should have no impact on any existing code. Applies in particular to the psycopg2 driver which does not otherwise quote special parameter names, but also strips leading underscores to suit Oracle (but not yet leading numbers, as some anon parameters are currently entirely numeric/underscore based); Oracle in any case continues to quote parameter names that include special characters. Fixes: #4837 Change-Id: I21cb654c3e4ef786114160b8b4295242720bf3f9