Fixed regression where the use of a :class:`_orm.hybrid_property` attribute
or a mapped :func:`_orm.composite` attribute as a key passed to the
:meth:`_dml.Update.values` method for an ORM-enabled :class:`_dml.Update`
statement, as well as when using it via the legacy
:meth:`_orm.Query.update` method, would be processed for incoming
ORM/hybrid/composite values within the compilation stage of the UPDATE
statement, which meant that in those cases where caching occurred,
subsequent invocations of the same statement would no longer receive the
correct values. This would include not only hybrids that use the
:meth:`_orm.hybrid_property.update_expression` method, but any use of a
plain hybrid attribute as well. For composites, the issue instead caused a
non-repeatable cache key to be generated, which would break caching and
could fill up the statement cache with repeated statements.

The :class:`_dml.Update` construct now handles the processing of key/value
pairs passed to :meth:`_dml.Update.values` and
:meth:`_dml.Update.ordered_values` up front when the construct is first
generated, before the cache key has been generated so that the key/value
pairs are processed each time, and so that the cache key is generated
against the individual column/value pairs that will ultimately be
used in the statement.

Fixes: #7209
Change-Id: I08f248d1d60ea9690b014c21439b775d951fb9e5

Fixed critical caching issue where the ORM's persistence feature using
INSERT..RETURNING would cache an incorrect query when mixing the "bulk
save" and standard "flush" forms of INSERT.

Fixes: #6793
Change-Id: Ifeb61c1226d3fa6d5e1c2e29b6f5ff77a27d6a2d

Added new method :meth:`_sql.HasCTE.add_cte` to each of the
:func:`_sql.select`, :func:`_sql.insert`, :func:`_sql.update` and
:func:`_sql.delete` constructs. This method will add the given
:class:`_sql.CTE` as an "independent" CTE of the statement, meaning it
renders in the WITH clause above the statement unconditionally even if it
is not otherwise referenced in the primary statement. This is a popular use
case on the PostgreSQL database where a CTE is used for a DML statement
that runs against database rows independently of the primary statement.

Fixes: #6752
Change-Id: Ibf635763e40269cbd10f4c17e208850d8e8d0188

Also replace http://pypi.python.org/pypi with https://pypi.org/project

Change-Id: I84b5005c39969a82140706472989f2a30b0c7685

Refined the behavior of ORM subquery rendering with regards to deferred
columns and column properties to be more compatible with that of 1.3 while
also providing for 1.4's newer features. As a subquery in 1.4 does not make
use of loader options, including :func:`_orm.deferred`, a subquery that is
against an ORM entity with deferred attributes will now render those
deferred attributes that refer directly to mapped table columns, as these
are needed in the outer SELECT if that outer SELECT makes use of these
columns; however a deferred attribute that refers to a composed SQL
expression as we normally do with :func:`_orm.column_property` will not be
part of the subquery, as these can be selected explicitly if needed in the
subquery. If the entity is being SELECTed from this subquery, the column
expression can still render on "the outside" in terms of the derived
subquery columns. This produces essentially the same behavior as when
working with 1.3. However in this case the fix has to also make sure that
the ``.selected_columns`` collection of an ORM-enabled :func:`_sql.select`
also follows these rules, which in particular allows recursive CTEs to
render correctly in this scenario, which were previously failing to render
correctly due to this issue.

As part of this change the _exported_columns_iterator() method has been
removed and logic simplified to use ._all_selected_columns from any
SelectBase object where _exported_columns_iterator() was used before.
Additionally sets up UpdateBase to include ReturnsRows in its hierarchy;
the literal point of ReturnsRows was to be a common base for UpdateBase
and SelectBase so it was kind of weird it wasn't there.

Fixes: #6661

Fixed issue in CTE constructs mostly relevant to ORM use cases where a
recursive CTE against "anonymous" labels such as those seen in ORM
``column_property()`` mappings would render in the
``WITH RECURSIVE xyz(...)`` section as their raw internal label and not a
cleanly anonymized name.

Fixes: #6663
Change-Id: I26219d4d8e6c0915b641426e9885540f74fae4d2

The ORM used in :term:`2.0 style` can now return ORM objects from the rows
returned by an UPDATE..RETURNING or INSERT..RETURNING statement, by
supplying the construct to :meth:`_sql.Select.from_statement` in an ORM
context.

Change-Id: I59c9754ff1cb3184580dd5194ecd2971d4e7f8e8
References: #5940

This introduces the ``_exclusive_against()`` utility decorator
that can be used to prevent repeated invocations of methods that
typically should only be called once.

An informative error message is now raised for a selected set of DML
methods (currently all part of :class:`_dml.Insert` constructs) if they are
called a second time, which would implicitly cancel out the previous
setting.  The methods altered include:
:class:`_sqlite.Insert.on_conflict_do_update`,
:class:`_sqlite.Insert.on_conflict_do_nothing` (SQLite),
:class:`_postgresql.Insert.on_conflict_do_update`,
:class:`_postgresql.Insert.on_conflict_do_nothing` (PostgreSQL),
:class:`_mysql.Insert.on_duplicate_key_update` (MySQL)

Fixes: #5169
Change-Id: I9278fa87cd3470dcf296ff96bb0fb17a3236d49d

Change-Id: Ic5bb19ca8be3cb47c95a0d3315d84cb484bac47c

Change-Id: I7fb37d45c29307b2213bebd0ef280d73804ac473

Multiple calls to "returning", e.g. :meth:`_sql.Insert.returning`,
may now be chained to add new columns to the RETURNING clause.

Fixes: #5695
Change-Id: Ie2dac4162f686c730e000e31dccfb38f9ce9c96e