Fixed 1.2 regression caused by :ticket:`4060` where the query used to
reflect SQL Server cross-schema foreign keys was limiting the criteria
incorrectly.

Additionally, added some rework of the inter-schema reflection tests
so that MySQL, MSSQL can be included, breaking out some of the
Postgresql-specific behaviors into separate requirements.

Fixes: #4234
Change-Id: I20c8e70707075f1767b79127c2c27d4b313c6515

SQL Server has an entirely different use for the TIMESTAMP
datatype that is unrelated to the SQL standard's version of this
type.   It is a read-only type that returns an incrementing
binary value.  The ROWVERSION name will supersede the TIMESTAMP
name.  Implement datatype objects for both, separate from the
base DateTime/TIMESTAMP class hierarchy, and also implement
an optional integer coercion feature.

Change-Id: Ie2bd43b7aac57760b8ec6ff6e26460e2086a95eb
Fixes: #4086

Fixed issue where CURRENT_TIMESTAMP would not reflect correctly
in the MariaDB 10.2 series due to a syntax change, where the function
is now represented as ``current_timestamp()``.

Fixes: #4096

MariaDB 10.2 now supports CHECK constraints (warning: use version 10.2.9
or greater due to upstream issues noted in :ticket:`4097`).  Reflection
now takes these CHECK constraints into account when they are present in
the ``SHOW CREATE TABLE`` output.

Fixes: #4098

Change-Id: I8666d61814e8145ca12cbecad94019b44af868e3

Change-Id: Ie0b78c79367933486528ca0ba686d4a9f16922b1
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/370

Added support for views that are unreflectable due to stale
table definitions, when calling :meth:`.MetaData.reflect`; a warning
is emitted for the table that cannot respond to ``DESCRIBE``
but the operation succeeds.  The MySQL dialect now
raises UnreflectableTableError which is in turn caught by
MetaData.reflect().  Reflecting the view standalone raises
this error directly.

Change-Id: Id8005219d8e073c154cc84a873df911b4a6cf4d6
Fixes: #3871

Added support for SQL comments on :class:`.Table` and :class:`.Column`
objects, via the new :paramref:`.Table.comment` and
:paramref:`.Column.comment` arguments.   The comments are included
as part of DDL on table creation, either inline or via an appropriate
ALTER statement, and are also reflected back within table reflection,
as well as via the :class:`.Inspector`.   Supported backends currently
include MySQL, Postgresql, and Oracle.

Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Fixes: #1546
Change-Id: Ib90683850805a2b4ee198e420dc294f32f15d35d

tested using pycodestyle version 2.2.0

Fixes: #3885
Change-Id: I5df43adc3aefe318f9eeab72a078247a548ec566
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/343

Fixed bug whereby the :meth:`.DDLEvents.column_reflect` event would not
allow a non-textual expression to be passed as the value of the
"default" for the new column, such as a :class:`.FetchedValue`
object to indicate a generic triggered default or a
:func:`.sql.expression.text` construct.  Clarified the documentation
in this regard as well.

Fixes: #3905

Change-Id: I829796c3e9f87f375149bebee7eef133a6876d4d

Avoid putting engine password in the exception message in
`MetaData.reflect` (since exception messages often appear in logs).
Use the same redacted `__repr__` implementation in
`TLEngine` as in its base class `Engine`

Change-Id: Ic0a7baea917a9c8d87dffdd82ef566673ab08e02
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/327

The "extend_existing" option of :class:`.Table` reflection would
cause indexes and constraints to be doubled up in the case that the parameter
were used with :meth:`.MetaData.reflect` (as the automap extension does)
due to tables being reflected both within the foreign key path as well
as directly.  A new de-duplicating set is passed through within the
:meth:`.MetaData.reflect` sequence to prevent double reflection in this
way.

Change-Id: Ibf6650c1e76a44ccbe15765fd79df2fa53d6bac7
Fixes: #3861