The :paramref:`_schema.MetaData.bind` argument as well as the overall
concept of "bound metadata" is deprecated in SQLAlchemy 1.4 and will be
removed in SQLAlchemy 2.0.  The parameter as well as related functions now
emit a :class:`_exc.RemovedIn20Warning` when :ref:`deprecation_20_mode` is
in use.

Added new parameter :paramref:`_automap.AutomapBase.prepare.autoload_with`
which supersedes :paramref:`_automap.AutomapBase.prepare.reflect`
and :paramref:`_automap.AutomapBase.prepare.engine`.

Fixes: #4634
Fixes: #5142

Change-Id: Iaabf9b481931e2fb68b97b5954c32e65772a298e

Reworked the proxy creation used by scoped_session() to be
based on fully copied code with augmented docstrings and
moved it into langhelpers.  asyncio session, engine,
connection can now take
advantage of it so that all non-async methods are availble.

Overall implementation of most important accessors / methods
on AsyncConnection, etc. , including awaitable versions
of invalidate, execution_options, etc.

In order to support an event dispatcher on the async
classes while still allowing them to hold __slots__,
make some adjustments to the event system to allow
that to be present, at least rudimentally.

Fixes: #5628
Change-Id: I5eb6929fc1e4fdac99e4b767dcfd49672d56e2b2

It's better, the majority of these changes look more readable to me.
also found some docstrings that had formatting / quoting issues.

Change-Id: I582a45fde3a5648b2f36bab96bad56881321899b

For most from_self() tests, move them into
test/orm/test_deprecated.py and replace the existing
test with one that uses aliased() plus a subquery.
This then revealed a few more issues.

Related items:

* Added slice() method to GenerativeSelect, to match that
  of orm.Query and to make possible migration of one of the
  from_self() tests.  moved the utility functions used for this
  from orm/util into sql/util.

* repairs a caching issue related to subqueryload
  where information being derived from the cached path info
  was mixing up with query information based on the per-query
  state, specifically an AliasedClass that is per query.

* for the above issue, it seemed like path_registry maybe
  had to change so that it represents AliasedClass objects
  as their cache key rather than on identity, but it wasn't
  needed.  still seems like it would be more correct.

* enhances the error message raised by coercions for a case
  such as when an AliasedClass holds onto a select() object
  and not a subquery(); will name the original and resolved
  object for clarity  (although how is AliasedClass able to
  accept a Select() object in the first place?)

* Added _set_propagate_attrs() to Query so that again if
  it's passed to AliasedClass, it doesn't raise an error
  during coercion, but again maybe that should also be
  rejected up front

Fixes: #5368
Change-Id: I5912aa611d899acc87a75eb5ee9f95990592f210

As the test suite has widespread use of many patterns
that are deprecated, enable SQLALCHEMY_WARN_20 globally
for the test suite but then break the warnings filter
out into a whole list of all the individual warnings
we are looking for.  this way individual changesets
can target a specific class of warning, as many of these
warnings will indivdidually affect dozens of files
and potentially hundreds of lines of code.

Many warnings are also resolved here as this
patch started out that way.   From this point
forward there should be changesets that target a
subset of the warnings at a time.

For expediency, updates some migration 2.0 docs
for ORM as well.

Change-Id: I98b8defdf7c37b818b3824d02f7668e3f5f31c94

The ORM Declarative system is now unified into the ORM itself, with new
import spaces under ``sqlalchemy.orm`` and new kinds of mappings.  Support
for decorator-based mappings without using a base class, support for
classical style-mapper() calls that have access to the declarative class
registry for relationships, and full integration of Declarative with 3rd
party class attribute systems like ``dataclasses`` and ``attrs`` is now
supported.

Fixes: #5508
Change-Id: I130b2b6edff6450bfe8a3e6baa099ff04b5471ff

This change includes mainly that the bracketed use within
select() is moved to positional, and keyword arguments are
removed from calls to the select() function.  it does not
yet fully address other issues such as keyword arguments passed
to the table.select().

Additionally, allows False / None to both be considered
as "disable" for all of select.correlate(), select.correlate_except(),
query.correlate(), which establishes consistency with
passing of ``False`` for the legact select(correlate=False)
argument.

Change-Id: Ie6c6e6abfbd3d75d4c8de504c0cf0159e6999108

`AsyncMethodRequired` is actually from
`sqlalchemy.ext.asyncio.exc`, so here it
should be referenced as `async_exc.AsyncMethodRequired`,
instead of `exc.AsyncMethodRequired`.

Fixes: #5529
Closes: #5545
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5545
Pull-request-sha: d8f885c587dd058f909d4f3bdbec3d0fca176680

Change-Id: I6886558bfd33d3e9e283fbd60c0ec971a1f22c0c

The docs are going to talk a lot about session.execute(select())
for ORM queries, and additionally it's much easier to help
users with queries and such if we can use this new syntax.
I'm hoping to see how hard it is to get a unified tutorial
started that switches to new syntax.  Basically, new syntax
is much easier to explain and less buggy.   But, if we
are starting to present new syntax with the explicit goal
of being easier to explain for less experienced programmers,
the "future" thing is going to just be an impediment
to that.

See if we can remove "future" from session.execute(),
so that ORM-enabled select() statements return ORM results
at that level.  This does not change the presence of the
"future" flag for the Session's construction and for its
transactional behaviors.

The only perceptible change of the future flag for
session.execute() is that session.execute(select()) where the
statement has ORM entities in it now returns ORM new
style tuples rather than old style tuples.   Like
mutating a URL, it's hopefully not very common that people
are doing this.

Change-Id: I0aa10322bb787d554d32772e3bc60548f1bf6206

It's not possible right now to use an association proxy element as a plain
column expression to be SELECTed from or used in a SQL function.  An
informative error is now raised when this occurs.

Fixes: #5542
Change-Id: I334e767ebc0b56c1dccc4a1e5185b0435af77b93