Change-Id: Ibcb0da3166b94aa58fa92d544c3e5cf75844546e

Added support for reflecting "identity" columns, which are now returned
as part of the structure returned by :meth:`_reflection.Inspector.get_columns`.
When reflecting full :class:`_schema.Table` objects, identity columns will
be represented using the :class:`_schema.Identity` construct.

Fixed compilation error on oracle for sequence and identity column
``nominvalue`` and ``nomaxvalue`` options that require no space in them.

Improved test compatibility with oracle 18.

As part of the support for reflecting :class:`_schema.Identity` objects,
the method :meth:`_reflection.Inspector.get_columns` no longer returns
``mssql_identity_start`` and ``mssql_identity_increment`` as part of the
``dialect_options``. Use the information in the ``identity`` key instead.

The mssql dialect will assume that at least MSSQL 2005 is used.
There is no hard exception raised if a previous version is detected,
but operations may fail for older versions.

Fixes: #5527
Fixes: #5324
Change-Id: If039fe637c46b424499e6bac54a2cbc0dc54cb57

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

This WIP is part of the final push for 1.4's docs
to fully "2.0-ize" what we can, and have it all ready.

So far this includes a rewrite of the 2.0 migration,
set up for the 1.4 /2.0 docs style, and a total redesign
of the index page using a new flex layout in zzzeeksphinx.

It also reworks some of the API reference sections
to have more subheaders.   zzzeeksphinx is also enhanced
to provide automatic summaries for all api doc section.

Change-Id: I01d360cb9c8749520246b96ee6496143c6037918

The automatic uniquing of rows on the client side is turned off for the new
:term:`2.0 style` of ORM querying.  This improves both clarity and
performance.  However, uniquing of rows on the client side is generally
necessary when using joined eager loading for collections, as there
will be duplicates of the primary entity for each element in the
collection because a join was used.  This uniquing must now be manually
enabled and can be achieved using the new
:meth:`_engine.Result.unique` modifier.   To avoid silent failure, the ORM
explicitly requires the method be called when the result of an ORM
query in 2.0 style makes use of joined load collections.    The newer
:func:`_orm.selectinload` strategy is likely preferable for eager loading
of collections in any case.

This changeset also fixes an issue where ORM-style "single entity"
results would not apply unique() correctly if results were returned
as tuples.

Fixes: #4395
Change-Id: Ie62e0cb68ef2a6d2120e968b79575a70d057212e

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 docs here were completely out of date and referred
to behaviors that are no longer true, behaviors that are
deprecated, etc.   For the moment, take out all the verbiage
so that nothing incorrect is present.   New ORM documentation
will need to be constructed to support this statement.

Change-Id: I4782aebb6443ceb68752c3b52b574fd30658ebc9

The server_side_cursors engine-wide feature relies upon
regexp parsing of statements a well as general guessing as
to when the feature should be used.   This is not within the
2.0 way of doing things and should be removed.

Additionally, mariadbconnector defaults to unbuffered cursors;
add new cursor hooks so that mariadbconnector can specify
buffered or unbuffered cursors without too much difficulty.
This will also correctly default mariadbconnector to buffered
cursors which should repair the segfaults we've been getting.

Try to restore the assert_raises that was removed in
5b6dfc0c38bf1f01da4b8 to see if mariadbconnector segfaults
are resolved.

Change-Id: I77f1c972c742e40694972f578140bb0cac8c39eb

As we have some tests that are against enums which
can raise on fetch, if we call scalar() and it fails,
we need to close the cursor.  mariadb segfaults
etc. seem to have been caused by this.

Change-Id: I8261f6fe7f972ae2d8702650440fd8d71e9bce53