yet the column is not the "auto increment" column, either because
it has a foreign key constraint or ``autoincrement=False`` set,
would attempt to fire the Sequence on INSERT for backends that don't
support sequences, when presented with an INSERT missing the primary
key value. This would take place on non-sequence backends like
SQLite, MySQL. [ticket:2896]
of the given names would not be taken into account when generating
the INSERT statement, thus producing a mismatch versus the column
names in the given SELECT statement. Also noted that
:meth:`.Insert.from_select` implies that Python-side insert defaults
cannot be used, since the statement has no VALUES clause. [ticket:2895]
``__repr__()``, particularly with regards to the MySQL integer/numeric/
character types which feature a wide variety of keyword arguments.
The ``__repr__()`` is important for use with Alembic autogenerate
for when Python code is rendered in a migration script.
[ticket:2893]
will now apply the given type to the given literal value on the
bind parameter side according
to the type given to the cast. This essentially replaces what would
normally be the detected type of the literal value. This only
takes effect if the auto-detected type of the literal value is either
"nulltype" (e.g. couldn't detect)
or a type that is of the same "affinity" as the cast type.
The net change here is that the :func:`.cast` function includes more
of the functionality already present in the :func:`.type_coerce` function.
backwards compatibility. A note about backslashing escapes is added.
Because the Text() construct now supports bind params better, the example
given in the code raises an exception now, so that should cover us.
The exception itself has been enhanced to include the key name of the
bound param. We're backporting this to 0.8 but 0.8 doesn't have the
text->bind behavior that raises.
column argument. If not a string, it checks that the object is
at least a :class:`.ColumnClause`, or an object that resolves to one,
and that the ``.table`` attribute, if present, refers to a
:class:`.TableClause` or subclass, and not something like an
:class:`.Alias`. Otherwise, a :class:`.ArgumentError` is raised.
[ticket:2883]
have been modified, such that the COLLATE operator is now of lower
precedence than the comparison operators. This has the effect that
a COLLATE applied to a comparison will not render parenthesis
around the comparison, which is not parsed by backends such as
MSSQL. The change is backwards incompatible for those setups that
were working around the issue by applying :meth:`.Operators.collate`
to an individual element of the comparison expression,
rather than the comparison expression as a whole. [ticket:2879]
more flexible ways to set up bound parameters and return types;
in particular, a :func:`.text` can now be turned into a full
FROM-object, embeddable in other statements as an alias or CTE
using the new method :meth:`.TextClause.columns`.
[ticket:2877]
- move out tests, dialect specific out of compiler, compiler tests use new API,
legacy API tests in test_selecatble
- add support for adaptation of ForUpdateArg, alias support in compilers
when a pre-DBAPI :class:`.StatementError` were raised within
:meth:`.Connection.execute`, causing encoding errors for
non-ASCII statements. The stringification now remains within
Python unicode thus avoiding encoding errors. [ticket:2871]
tuple is; this is accomplished via ensuring tuple() conversion on
both sides within the ``__eq__()`` method as well as
the addition of a ``__lt__()`` method. [ticket:2848]
🎫`2369` and 🎫`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 🎫`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
so that the custom type isn't exposed to an operation that is against the
"impl" type's constraint, [ticket:2842]
- this change showed up as some recursion overflow in pickling with labels,
add a __reduce__() there....pickling of expressions is less and less something
that's very viable...
all :attr:`.SchemaItem.info` dictionaries from all :class:`.SchemaItem`
objects within the structure including columns, constraints,
foreign keys, etc. As these dictionaries
are copies, they are independent of the original dictionary.
Previously, only the ``.info`` dictionary of :class:`.Column` was transferred
within this operation, and it was only linked in place, not copied.
[ticket:2716]
if it was generated from a :class:`.Column` that didn't specify ``unique``
(where it defaults to ``None``). The flag will now always be ``True`` or
``False``. [ticket:2825]
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.
events are called, so that attachment events can be used to dynamically
generate a name for the index based on the parent table and/or
columns. [ticket:2835]
:func:`.foreign` on a :class:`.Column` before association with a parent
:class:`.Table` could produce issues related to the parent table not
rendering within joins, due to the inherent copy operation performed
by an annotation. [ticket:2813]
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]
the import structure of many core modules.
``sqlalchemy.schema`` and ``sqlalchemy.types``
remain in the top-level package, but are now just lists of names
that pull from within ``sqlalchemy.sql``. Their implementations
are now broken out among ``sqlalchemy.sql.type_api``, ``sqlalchemy.sql.sqltypes``,
``sqlalchemy.sql.schema`` and ``sqlalchemy.sql.ddl``, the last of which was
moved from ``sqlalchemy.engine``. ``sqlalchemy.sql.expression`` is also
a namespace now which pulls implementations mostly from ``sqlalchemy.sql.elements``,
``sqlalchemy.sql.selectable``, and ``sqlalchemy.sql.dml``.
Most of the "factory" functions
used to create SQL expression objects have been moved to classmethods
or constructors, which are exposed in ``sqlalchemy.sql.expression``
using a programmatic system. Care has been taken such that all the
original import namespaces remain intact and there should be no impact
on any existing applications. The rationale here was to break out these
very large modules into smaller ones, provide more manageable lists
of function names, to greatly reduce "import cycles" and clarify the
up-front importing of names, and to remove the need for redundant
functions and documentation throughout the expression package.
Mike Bayer