Change-Id: I14db8e9c69a832b0f5dae8036db3c0a70bb49edd

Change-Id: Ic38dbc640aa0fe8a784a5b5e57c45a41eb0ea01b

This patch adds new warnings for all elements that
don't indicate their caching behavior, including user-defined
ClauseElement subclasses and third party dialects.
it additionally adds new documentation to discuss an apparent
performance degradation in 1.4 when caching is disabled as a
result in the significant expense incurred by ORM
lazy loaders, which in 1.3 used BakedQuery so were actually
cached.

As a result of adding the warnings, a fair degree of
lesser used SQL expression objects identified that they did not
define caching behavior so would have been producing
``[no key]``, including PostgreSQL constructs ``hstore``
and ``array``.  These have been amended to use inherit
cache where appropriate.  "on conflict" constructs in
PostgreSQL, MySQL, SQLite still explicitly don't generate
a cache key at this time.

The change also adds a test for all constructs via
assert_compile() to assert they will not generate cache
warnings.

Fixes: #7394
Change-Id: I85958affbb99bfad0f5efa21bc8f2a95e7e46981
(cherry picked from commit 22deafe15289d2be55682e1632016004b02b62c0)

An extra layer of warning messages has been added to the functionality
of :meth:`_orm.Query.join` and the ORM version of
:meth:`_sql.Select.join`, where a few places where "automatic aliasing"
continues to occur will now be called out as a pattern to avoid, mostly
specific to the area of joined table inheritance where classes that share
common base tables are being joined together without using explicit aliases.
One case emits a legacy warning for a pattern that's not recommended,
the other case is fully deprecated.

The automatic aliasing within ORM join() which occurs for overlapping
mapped tables does not work consistently with all APIs such as
``contains_eager()``, and rather than continue to try to make these use
cases work everywhere, replacing with a more user-explicit pattern
is clearer, less prone to bugs and simplifies SQLAlchemy's internals
further.

The warnings include links to the errors.rst page where each pattern is
demonstrated along with the recommended pattern to fix.

* Improved the exception message generated when configuring a mapping with
  joined table inheritance where the two tables either have no foreign key
  relationships set up, or where they have multiple foreign key relationships
  set up. The message is now ORM specific and includes context that the
  :paramref:`_orm.Mapper.inherit_condition` parameter may be needed
  particularly for the ambiguous foreign keys case.

* Add explicit support in the _expect_warnings() assertion for nested
  _expect_warnings calls

* generalize the NoCache fixture, which we also need to catch warnings
  during compilation consistently

* generalize the __str__() method for the HasCode mixin so all warnings
  and errors include the code link in their string

Fixes: #6974
Change-Id: I84ed79ba2112c39eaab7973b6d6f46de7fa80842

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

Change-Id: I488c9557eda390e4a88319affd4c8813ee274f80

Executing a :class:`_sql.Subquery` using :meth:`_engine.Connection.execute`
is deprecated and will emit a deprecation warning; this use case was an
oversight that should have been removed from 1.4. The operation will now
execute the underlying :class:`_sql.Select` object directly for backwards
compatibility. Similarly, the :class:`_sql.CTE` class is also not
appropriate for execution. In 1.3, attempting to execute a CTE would result
in an invalid "blank" SQL statement being executed; since this use case was
not working it now raises :class:`_exc.ObjectNotExecutableError`.
Previously, 1.4 was attempting to execute the CTE as a statement however it
was working only erratically.

The change also breaks out StatementRole from ReturnsRowsRole, as these
roles should not be in the same lineage (some statements don't return
rows, the whole class of ReturnsRows that are from clauses are
not statements).    Consolidate StatementRole and
CoerceTextStatementRole as there's no usage difference between
these.   Simplify some old tests that were trying to make
sure that "execution options" didn't transmit from a cte/subquery
out to a select; as cte/subuqery() aren't executable in any case
the options are removed.

Fixes: #6204
Change-Id: I62613b7ab418afdd22c409eae75659e3f52fb65f

Implemented support for "table valued functions" along with additional
syntaxes supported by PostgreSQL, one of the most commonly requested
features. Table valued functions are SQL functions that return lists of
values or rows, and are prevalent in PostgreSQL in the area of JSON
functions, where the "table value" is commonly referred towards as the
"record" datatype. Table valued functions are also supported by Oracle and
SQL Server.

Moved from I5b093b72533ef695293e737eb75850b9713e5e03 due
to accidental push

Fixes: #3566
Change-Id: Iea36d04c80a5ed3509dcdd9ebf0701687143fef5