This test is failing on windows due to the new SQlite
provisioning that seemed to be failing to delete schema files
as they are still used by the main connection.

Change-Id: I51093212ebfe1053f26b279c56c8fec0408806da

Fixed reflection bug where Oracle "name normalize" would not work correctly
for reflection of symbols that are in the "PUBLIC" schema, such as
synonyms, meaning the PUBLIC name could not be indicated as lower case on
the Python side for the :paramref:`_schema.Table.schema` argument. Using
uppercase "PUBLIC" would work, but would then lead to awkward SQL queries
including a quoted ``"PUBLIC"`` name as well as indexing the table under
uppercase "PUBLIC", which was inconsistent.

Fixes: #9459
Change-Id: I989bd1e794a5b5ac9aae4f4a8702f14c56cd74c2

pymssql seems to be maintained again and seems to be working
completely, so let's try re-enabling it.

Fixed issue in the new :class:`.Uuid` datatype which prevented it from
working with the pymssql driver. As pymssql seems to be maintained again,
restored testing support for pymssql.

Tweaked the pymssql dialect to take better advantage of
RETURNING for INSERT statements in order to retrieve last inserted primary
key values, in the same way as occurs for the mssql+pyodbc dialect right
now.

Identified that the ``sqlite`` and ``mssql+pyodbc`` dialects are now
compatible with the SQLAlchemy ORM's "versioned rows" feature, since
SQLAlchemy now computes rowcount for a RETURNING statement in this specific
case by counting the rows returned, rather than relying upon
``cursor.rowcount``.  In particular, the ORM versioned rows use case
(documented at :ref:`mapper_version_counter`) should now be fully
supported with the SQL Server pyodbc dialect.

Change-Id: I38a0666587212327aecf8f98e86031ab25d1f14d
References: #5321
Fixes: #9414

Fixed bug that prevented SQLAlchemy to connect when using a very old
sqlite version (before 3.9) on python 3.8+.

Fixes: #9379
Change-Id: I10ca347398221c952e1a572dc6ef80e491d1f5cf

Fixes: #9401
Change-Id: Ie10192348749567110f53ae618fc724f37d1a6a1

This adds the very small plugin flake8-import-single which
will prevent us from having an import with more than one symbol
on a line.

Flake8 by itself prevents this pattern with E401:

import collections, os, sys

However does not do anything with this:

from sqlalchemy import Column, text

Both statements have the same issues generating merge artifacts
as well as presenting a manual decision to be made.   While
zimports generally cleans up such imports at the top level, we
don't enforce zimports / pre-commit use.

the plugin finds the same issue for imports that are inside of
test methods.   We shouldn't usually have imports in test methods
so most of them here are moved to be top level.

The version is pinned at 0.1.5; the project seems to have no
activity since 2019, however there are three 0.1.6dev releases
on pypi which stopped in September 2019, they seem to be
experiments with packaging.  The source for 0.1.5
is extremely simple and only reveals one method to flake8
(the run() method).

Change-Id: Icea894e43bad9c0b5d4feb5f49c6c666d6ea6aa1

Follow up of 71693c94d52612a5e88128575ff308ee4a923c00

Change-Id: Icc9d9942bda92171581dec82cf0cacbd3e3e4162

ExcludeConstraint correctly uses literal compile
when compiling expression ddl.

Fixes: #9349
Change-Id: I11a994ac46556a972afc696a2baad7ddbdd3de97