:ticket:`2369` and :ticket:`2587` where a nested join with one side already an aliased select would fail to translate the ON clause on the outside correctly; in the ORM this could be seen when using a SELECT statement as a "secondary" table. [ticket:2858]
with conjunctions, e.g. ``None`` :func:`.expression.null` :func:`.expression.true` :func:`.expression.false`, including consistency in rendering NULL in conjunctions, "short-circuiting" of :func:`.and_` and :func:`.or_` expressions which contain boolean constants, and rendering of boolean constants and expressions as compared to "1" or "0" for backends that don't feature ``true``/``false`` constants. [ticket:2804]
specified) is now copied when used in a typed expression, and the new copy is assigned the actual type of the compared column. Previously, this logic would occur on the given :func:`.bindparam` in place. Additionally, a similar process now occurs for :func:`.bindparam` constructs passed to :meth:`.ValuesBase.values` for a :class:`.Insert` or :class:`.Update` construct. [ticket:2850]
e.g. values that are normally bound parameters but due to context must be rendered as strings, typically within DDL constructs such as CHECK constraints and indexes (note that "literal bind" values become used by DDL as of :ticket:`2742`). A new method :meth:`.TypeEngine.literal_processor` serves as the base, and :meth:`.TypeDecorator.process_literal_param` is added to allow wrapping of a native literal rendering method. [ticket:2838] - enhance _get_colparams so that we can send flags like literal_binds into INSERT statements - add support in PG for inspecting standard_conforming_strings - add a new series of roundtrip tests based on INSERT of literal plus SELECT for basic literal rendering in dialect suite
mssql to ensure that any literal SQL expression values are rendered directly as literals, instead of as bound parameters, within a CREATE INDEX statement. [ticket:2742] - don't need expression_as_ddl(); literal_binds and include_table take care of this functionality.
pattern
instead of relying upon various ``quote=True`` flags being passed around, these flags are converted into rich string objects with quoting information included at the point at which they are passed to common schema constructs like :class:`.Table`, :class:`.Column`, etc. This solves the issue of various methods that don't correctly honor the "quote" flag such as :meth:`.Engine.has_table` and related methods. The :class:`.quoted_name` object is a string subclass that can also be used explicitly if needed; the object will hold onto the quoting preferences passed and will also bypass the "name normalization" performed by dialects that standardize on uppercase symbols, such as Oracle, Firebird and DB2. The upshot is that the "uppercase" backends can now work with force-quoted names, such as lowercase-quoted names and new reserved words. [ticket:2812]
to rely upon server generated version identifiers, using triggers or other database-provided versioning features, by passing the value ``False``. The ORM will use RETURNING when available to immediately load the new version identifier, else it will emit a second SELECT. [ticket:2793] - The ``eager_defaults`` flag of :class:`.Mapper` will now allow the newly generated default values to be fetched using an inline RETURNING clause, rather than a second SELECT statement, for backends that support RETURNING. - Added a new variant to :meth:`.ValuesBase.returning` called :meth:`.ValuesBase.return_defaults`; this allows arbitrary columns to be added to the RETURNING clause of the statement without interfering with the compilers usual "implicit returning" feature, which is used to efficiently fetch newly generated primary key values. For supporting backends, a dictionary of all fetched values is present at :attr:`.ResultProxy.returned_defaults`. - add a glossary entry for RETURNING - add documentation for version id generation, [ticket:867]