Improved support for column names that contain percent signs in the string,
including repaired issues involving anoymous labels that also embedded a
column name with a percent sign in it, as well as re-established support
for bound parameter names with percent signs embedded on the psycopg2
dialect, using a late-escaping process similar to that used by the
cx_Oracle dialect.
* Added new constructor for _anonymous_label() that ensures incoming
string tokens based on column or table names will have percent
signs escaped; abstracts away the format of the label.
* generalized cx_Oracle's quoted_bind_names facility into the compiler
itself, and leveraged this for the psycopg2 dialect's issue with
percent signs in names as well. the parameter substitution is now
integrated with compiler.construct_parameters() as well as the
recently reworked set_input_sizes(), reducing verbosity in the
cx_Oracle dialect.
Fixes: #5653
Change-Id: Ia2ad13ea68b4b0558d410026e5a33f5cb3fbab2c
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
The :meth:`_sql.Join.alias` method is deprecated and will be removed in
SQLAlchemy 2.0. An explicit select + subquery, or aliasing of the inner
tables, should be used instead.
Fixes: #5010
Change-Id: Ic913afc31f0d70b0605f9a7af2742a0de1f9ad19
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
in order to accommodate relationship loaders
with lambda caching, a lot more is needed. This is
a full refactor of the lambda system such that it
now has two levels of caching; the first level caches what
can be known from the __code__ element, then the next level
of caching is against the lambda itself and the contents
of __closure__. This allows for the elements inside
the lambdas, like columns and entities, to change and
then be part of the cache key. Lazy/selectinloads' use of
baked queries had to add distinct cache key elements,
which was attempted here but overall things needed to be
more robust than that.
This commit is broken out from the very long and sprawling
commit at Id6b5c03b1ce9ddb7b280f66792212a0ef0a1c541 .
Change-Id: I29a513c98917b1d503abfdd61e6b6e8800851aa8
This is kind of a mixed bag of all kinds to help get us
to 1.4 betas. The documentation stuff is a work in
progress. Lots of other relatively small changes to
APIs and things. More commits will follow to continue
improving the documentation and transitioning to the
1.4/2.0 hybrid documentation. In particular some refinements
to Session usage models so that it can match Engine's
scoping / transactional patterns, and a decision to
start moving away from "subtransactions" completely.
* add select().from_statement() to produce FromStatement in an
ORM context
* begin referring to select() that has "plugins" for the few edge
cases where select() will have ORM-only behaviors
* convert dynamic.AppenderQuery to its own object that can use
select(), though at the moment it uses Query to support legacy
join calling forms.
* custom query classes for AppenderQuery are replaced by
do_orm_execute() hooks for custom actions, a separate gerrit
will document this
* add Session.get() to replace query.get()
* Deprecate session.begin->subtransaction. propose within the
test suite a hypothetical recipe for apps that rely on this
pattern
* introduce Session construction level context manager,
sessionmaker context manager, rewrite the whole top of the
session_transaction.rst documentation. Establish context manager
patterns for Session that are identical to engine
* ensure same begin_nested() / commit() behavior as engine
* devise all new "join into an external transaction" recipe,
add test support for it, add rules into Session so it
just works, write new docs. need to ensure this doesn't
break anything
* vastly reduce the verbosity of lots of session docs as
I dont think people read this stuff and it's difficult
to keep current in any case
* constructs like case(), with_only_columns() really need
to move to *columns, add a coercion rule to just change
these.
* docs need changes everywhere I look. in_() is not in
the Core tutorial? how do people even know about it?
Remove tons of cruft from Select docs, etc.
* build a system for common ORM options like populate_existing
and autoflush to populate from execution options.
* others?
Change-Id: Ia4bea0f804250e54d90b3884cf8aab8b66b82ecf
Several weeks of using the future_select() construct
has led to the proposal there be just one select() construct
again which features the new join() method, and otherwise accepts
both the 1.x and 2.x argument styles. This would make
migration simpler and reduce confusion.
However, confusion may be increased by the fact that select().join()
is different Current thinking is we may be better off
with a few hard behavioral changes to old and relatively unknown APIs
rather than trying to play both sides within two extremely similar
but subtly different APIs. At the moment, the .join() thing seems
to be the only behavioral change that occurs without the user
taking any explicit steps. Session.execute() will still
behave the old way as we are adding a future flag.
This change also adds the "future" flag to Session() and
session.execute(), so that interpretation of the incoming statement,
as well as that the new style result is returned, does not
occur for existing applications unless they add the use
of this flag.
The change in general is moving the "removed in 2.0" system
further along where we want the test suite to fully pass
even if the SQLALCHEMY_WARN_20 flag is set.
Get many tests to pass when SQLALCHEMY_WARN_20 is set; this
should be ongoing after this patch merges.
Improve the RemovedIn20 warning; these are all deprecated
"since" 1.4, so ensure that's what the messages read.
Make sure the inforamtion link is on all warnings.
Add deprecation warnings for parameters present and
add warnings to all FromClause.select() types of methods.
Fixes: #5379Fixes: #5284
Change-Id: I765a0b912b3dcd0e995426427d8bb7997cbffd51
References: #5159
This patch contains a variety of ORM and expression layer
tweaks to support ORM constructs in select() statements,
without the 1.3.x requiremnt in Query that a full
_compile_context() + new select() is needed in order to
get a working statement object.
Includes such tweaks as the ability to implement
aliased class of an aliased class,
as we are looking to fully support ACs against subqueries,
as well as the ability to access anonymously-labeled
ColumnProperty expressions within subqueries by
naming the ".key" of the label after the property
key. Some tuning to query.join() as well
as ORMJoin internals to allow things to work more
smoothly.
Change-Id: Id810f485c5f7ed971529489b84694e02a3356d6d
The type coerce element did not correctly apply grouping rules when using
in an expression
Fixes: #5344
Change-Id: Id67b0e60ac54f8992f931aaed62731672f60c96c
Supercedes: If78fbb557c6f2cae637799c3fec2cbc5ac248aaf
Trying to see if by making the cache key memoized, we
still can have the older "identity" form of caching
which is the cheapest of all, at the same time as the
newer "cache key each time" version that is not nearly
as cheap; but still much cheaper than no caching at all.
Also needed is a per-execution update of _keymap when
we invoke from a cached select, so that Column objects
that are anonymous or otherwise adapted will match up.
this is analogous to the adaption of bound parameters
from the cache key.
Adds test coverage for the keymap / construct_params()
changes related to caching. Also hones performance
to a large extent for statement construction and
cache key generation.
Also includes a new memoized attribute
approach that vastly simplifies the previous approach
of "group_expirable_memoized_property" and finally
integrates cleanly with _clone(), _generate(), etc.
no more hardcoding of attributes is needed, as well
as that most _reset_memoization() calls are no longer
needed as the reset is inherent in a _generate() call;
this also has dramatic performance improvements.
Change-Id: I95c560ffcbfa30b26644999412fb6a385125f663
Enhanced the disambiguating labels feature of the
:func:`~.sql.expression.select` construct such that when a select statement
is used in a subquery, repeated column names from different tables are now
automatically labeled with a unique label name, without the need to use the
full "apply_labels()" feature that conbines tablename plus column name.
The disambigated labels are available as plain string keys in the .c
collection of the subquery, and most importantly the feature allows an ORM
:func:`.orm.aliased` construct against the combination of an entity and an
arbitrary subquery to work correctly, targeting the correct columns despite
same-named columns in the source tables, without the need for an "apply
labels" warning.
The existing labeling style is now called
LABEL_STYLE_TABLENAME_PLUS_COL. This labeling style will remain used
throughout the ORM as has been the case for over a decade, however,
the new disambiguation scheme could theoretically replace this scheme
entirely. The new scheme would dramatically alter how SQL looks
when rendered from the ORM to be more succinct but arguably harder
to read.
The tablename_columnname scheme used by Join.c is unaffected here,
as that's still hardcoded to that scheme.
Fixes: #5221
Change-Id: Ib47d9e0f35046b3afc77bef6e65709b93d0c3026
Continuation of I408e0b8be91fddd77cf279da97f55020871f75a9
- add an options() method to the base Generative construct.
this will be where ORM options can go
- Change Null, False_, True_ to be singletons, so that
we aren't instantiating them and having to use isinstance.
The previous issue with this was that they would produce dupe
labels in SELECT statements. Apply the duplicate column
logic, newly added in 1.4, to these objects as well as to
non-apply-labels SELECT statements in general as a means of
improving this.
- create a revised system for generating ClauseList compilation
constructs that simplfies up front creation to not actually
use ClauseList; a simple tuple is rendered by the compiler
using the same constrcution rules as what are used for
ClauseList but without creating the actual object. Apply
to Select, CompoundSelect, revise Update, Delete
- Select, CompoundSelect get an initial CompileState
implementation. All methods used only within compilation
are moved here
- refine update/insert/delete compile state to not require
an outside boolean
- refine and simplify Select._copy_internals
- rework bind(), which is going away, to not use some
of the internal traversal stuff
- remove "autocommit", "for_update" parameters from Select,
references #4643
- remove "autocommit" parameter from TextClause ,
references #4643
- add deprecation warnings for statement.execute(),
engine.execute(), statement.scalar(), engine.scalar().
Fixes: #5193
Change-Id: I04ca0152b046fd42c5054ba10f37e43fc6e5a57b
Reorganization of Select() is the first major element
of the 2.0 restructuring. In order to start this we need
to first create the new Select constructor and apply legacy
elements to the old one. This in turn necessitates
starting up the RemovedIn20Warning concept which itself
need to refer to "sqlalchemy.future", so begin to establish
this basic framework. Additionally, update the
DML constructors with the newer no-keyword style. Remove
the use of the "pending deprecation" and fix Query.add_column()
deprecation which was not acting as deprecated.
Fixes: #4845Fixes: #4648
Change-Id: I0c7a22b2841a985e1c379a0bb6c94089aae6264c
Creating an :func:`.and_` or :func:`.or_` construct with no arguments or
empty ``*args`` will now emit a deprecation warning, as the SQL produced is
a no-op (i.e. it renders as a blank string). This behavior is considered to
be non-intuitive, so for empty or possibly empty :func:`.and_` or
:func:`.or_` constructs, an appropriate default boolean should be included,
such as ``and_(True, *args)`` or ``or_(False, *args)``. As has been the
case for many major versions of SQLAlchemy, these particular boolean
values will not render if the ``*args`` portion is non-empty.
As there are some internal cases where an empty and_() construct is used
in order to build an optional WHERE expression, a private
utility function is added to suit this use case.
Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Fixes: #5054Closes: #5062
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5062
Pull-request-sha: 5ca2f27281
Change-Id: I599b9c8befa64d9a59a35ad7dd84ff400e3aa647
The "expanding IN" feature, which generates IN expressions at query
execution time which are based on the particular parameters associated with
the statement execution, is now used for all IN expressions made against
lists of literal values. This allows IN expressions to be fully cacheable
independently of the list of values being passed, and also includes support
for empty lists. For any scenario where the IN expression contains
non-literal SQL expressions, the old behavior of pre-rendering for each
position in the IN is maintained. The change also completes support for
expanding IN with tuples, where previously type-specific bind processors
weren't taking effect.
As part of this change, a more explicit separation between
"literal execute" and "post compile" bound parameters is being made;
as the "ansi bind rules" feature is rendering bound parameters
inline, as we now support "postcompile" generically, these should
be used here, however we have to render literal values at
execution time even for "expanding" parameters. new test fixtures
etc. are added to assert everything goes to the right place.
Fixes: #4645
Change-Id: Iaa2b7bfbfaaf5b80799ee17c9b8507293cba6ed1
Created new visitor system called "internal traversal" that
applies a data driven approach to the concept of a class that
defines its own traversal steps, in contrast to the existing
style of traversal now known as "external traversal" where
the visitor class defines the traversal, i.e. the SQLCompiler.
The internal traversal system now implements get_children(),
_copy_internals(), compare() and _cache_key() for most Core elements.
Core elements with special needs like Select still implement
some of these methods directly however most of these methods
are no longer explicitly implemented.
The data-driven system is also applied to ORM elements that
take part in SQL expressions so that these objects, like mappers,
aliasedclass, query options, etc. can all participate in the
cache key process.
Still not considered is that this approach to defining traversibility
will be used to create some kind of generic introspection system
that works across Core / ORM. It's also not clear if
real statement caching using the _cache_key() method is feasible,
if it is shown that running _cache_key() is nearly as expensive as
compiling in any case. Because it is data driven, it is more
straightforward to optimize using inlined code, as is the case now,
as well as potentially using C code to speed it up.
In addition, the caching sytem now accommodates for anonymous
name labels, which is essential so that constructs which have
anonymous labels can be cacheable, that is, their position
within a statement in relation to other anonymous names causes
them to generate an integer counter relative to that construct
which will be the same every time. Gathering of bound parameters
from any cache key generation is also now required as there is
no use case for a cache key that does not extract bound parameter
values.
Applies-to: #4639
Change-Id: I0660584def8627cad566719ee98d3be045db4b8d
The :class:`.Join` construct no longer considers the "onclause" as a source
of additional FROM objects to be omitted from the FROM list of an enclosing
:class:`.Select` object as standalone FROM objects. This applies to an ON
clause that includes a reference to another FROM object outside the JOIN;
while this is usually not correct from a SQL perspective, it's also
incorrect for it to be omitted, and the behavioral change makes the
:class:`.Select` / :class:`.Join` behave a bit more intuitively.
Fixes: #4621
Change-Id: Iaa1e75b7c59b21e9701ab3c9b69e66930feaf8ee
As of #4753 we allow duplicate columns. This creates some new
problems that there can be duplicate columns in a subquery
which are then not addressible on the outside because they
are ambiguous (Postgresql has this behavior at least). Additionally
it creates situations where we are making an anon label of an
anon label which is leaking into the query.
New logic for generating anon labels handles this situation and
also alters the .c collection
of a subquery such that we are only getting the first column
from the derived selectable that has that name, the subsequent ones
have a new deduping label with two underscores and are not exposed
in .c. The dedupe logic when rendering the columns will handle
duplicate label names for different columns, vs. the same column
repeated, as separate cases.
Fixes: #4892
Change-Id: I929fbd8da14bcc239e0481c24bbd9b5ce826e8fa
generation is to be enhanced to include caching
functionality, so ensure that Query and all generative in Core
(e.g. select, DML etc) are using the same generations system.
Additionally, deprecate Select.append methods and state
Select methods independently of their append versions.
Mutability of expression objects is a special case only when
generating new objects during a visit.
Fixes: #4637
Change-Id: I3dfac00d5e0f710c833b236f7a0913e1ca24dde4
Added new entity-targeting capabilities to the :class:`.Query` object to
help with the case where the :class:`.Session` is using a bind dictionary
against mapped classes, rather than a single bind, and the :class:`.Query`
is against a Core statement that was ultimately generated from a method
such as :meth:`.Query.subquery`; a deep search is performed to locate
any ORM entity related to the query in order to locate a mapper if
one is not otherwise present.
Fixes: #4829
Change-Id: I95cf325a5aba21baec4b313246c6f4d692284820
Fixed issue where internal cloning of SELECT constructs could lead to a key
error if the copy of the SELECT changed its state such that its list of
columns changed. This was observed to be occurring in some ORM scenarios
which may be unique to 1.3 and above, so is partially a regression fix.
For 1.4, the _is_clone_of key will be removed entirely as it seems to
have no purpose. This commit is the initial backport to 1.3 which
includes tests.
Fixes: #4780
Change-Id: I0c64962a2eba3763bea3107fc7c7d7aed8244430
The :func:`.select` construct and related constructs now allow for
duplication of column labels and columns themselves in the columns clause,
mirroring exactly how column expressions were passed in. This allows
the tuples returned by an executed result to match what was SELECTed
for in the first place, which is how the ORM :class:`.Query` works, so
this establishes better cross-compatibility between the two constructs.
Additionally, it allows column-positioning-sensitive structures such as
UNIONs (i.e. :class:`.CompoundSelect`) to be more intuitively constructed
in those cases where a particular column might appear in more than one
place. To support this change, the :class:`.ColumnCollection` has been
revised to support duplicate columns as well as to allow integer index
access.
Fixes: #4753
Change-Id: Ie09a8116f05c367995c1e43623c51e07971d3bf0
As part of the SQLAlchemy 2.0 migration project, a conceptual change has
been made to the role of the :class:`.SelectBase` class hierarchy,
which is the root of all "SELECT" statement constructs, in that they no
longer serve directly as FROM clauses, that is, they no longer subclass
:class:`.FromClause`. For end users, the change mostly means that any
placement of a :func:`.select` construct in the FROM clause of another
:func:`.select` requires first that it be wrapped in a subquery first,
which historically is through the use of the :meth:`.SelectBase.alias`
method, and is now also available through the use of
:meth:`.SelectBase.subquery`. This was usually a requirement in any
case since several databases don't accept unnamed SELECT subqueries
in their FROM clause in any case.
See the documentation in this change for lots more detail.
Fixes: #4617
Change-Id: I0f6174ee24b9a1a4529168e52e855e12abd60667
Fixed an unlikely issue where the "corresponding column" routine for unions
and other :class:`.CompoundSelect` objects could return the wrong column in
some overlapping column situtations, thus potentially impacting some ORM
operations when set operations are in use, if the underlying
:func:`.select` constructs were used previously in other similar kinds of
routines, due to a cached value not being cleared.
Fixes: #4747
Change-Id: I7fb134cac3604f8fe62e220fb24a0945d0a1c56f
This is a very useful assertion which prevents unused variables
from being set up allows code to be more readable and sometimes
even more efficient. test suites seem to be where the most
problems are and there do not seem to be documentation examples
that are using this, or at least the linter is not taking effect
within rst blocks.
Change-Id: I2b3341d8dd14da34879d8425838e66a4b9f8e27d
The Alias object no longer has "element" and "original", it now
has "wrapped" and "element" (the name .original is also left
as a descriptor for legacy access by third party dialects).
These two data members refer to the
dual roles Alias needs to play, where in the Python sense it needs
to refer to the thing it was applied against directly, whereas in the
SQL sense it needs to refer to the ultimate "non-alias" thing it
refers towards. Both are necessary to maintain. However, the change
here has each Alias object access the non-Alias object immediately
so that the "unwrapping" is simpler and does not need any special
logic.
In the SQL sense, Alias objects don't nest, the only potential
was that of the CTE, however there is no such thing as
a nested CTE, see link below.
This change is an interim change along the way to breaking Alias
into more classes and breaking away Select objects from being
FromClause objects.
Change-Id: Ie7a0d064226cb074ca745505129b5ec7d879e389
References: https://stackoverflow.com/questions/1413516/can-you-create-nested-with-clauses-for-common-table-expressions
as SELECT statements will have subquery() and not alias(),
start getting ready for the places where the ORM coerces SELECTs
into subqueries and be ready to warn about it
Change-Id: I90d4b6cae2c72816c6b192016ce074589caf4731
A major refactoring of all the functions handle all detection of
Core argument types as well as perform coercions into a new class hierarchy
based on "roles", each of which identify a syntactical location within a
SQL statement. In contrast to the ClauseElement hierarchy that identifies
"what" each object is syntactically, the SQLRole hierarchy identifies
the "where does it go" of each object syntactically. From this we define
a consistent type checking and coercion system that establishes well
defined behviors.
This is a breakout of the patch that is reorganizing select()
constructs to no longer be in the FromClause hierarchy.
Also includes a rename of as_scalar() into scalar_subquery(); deprecates
automatic coercion to scalar_subquery().
Partially-fixes: #4617
Change-Id: I26f1e78898693c6b99ef7ea2f4e7dfd0e8e1a1bd
The :class:`.Alias` class and related subclasses :class:`.CTE`,
:class:`.Lateral` and :class:`.TableSample` have been reworked so that it is
not possible for a user to construct the objects directly. These constructs
require that the standalone construction function or selectable-bound method
be used to instantiate new objects.
Fixes: #4509
Change-Id: I74ae4786cb3ae625dab33b00bfd6bdc4e1219139
A large change throughout the library has ensured that all objects, parameters,
and behaviors which have been noted as deprecated or legacy now emit
``DeprecationWarning`` warnings when invoked. As the Python 3 interpreter now
defaults to displaying deprecation warnings, as well as that modern test suites
based on tools like tox and pytest tend to display deprecation warnings,
this change should make it easier to note what API features are obsolete.
See the notes added to the changelog and migration notes for further
details.
Fixes: #4393
Change-Id: If0ea11a1fc24f9a8029352eeadfc49a7a54c0a1b
Applied on top of a pure run of black -l 79 in
I7eda77fed3d8e73df84b3651fd6cfcfe858d4dc9, this set of changes
resolves all remaining flake8 conditions for those codes
we have enabled in setup.cfg.
Included are resolutions for all remaining flake8 issues
including shadowed builtins, long lines, import order, unused
imports, duplicate imports, and docstring issues.
Change-Id: I4f72d3ba1380dd601610ff80b8fb06a2aff8b0fe
This is a straight reformat run using black as is, with no edits
applied at all.
The black run will format code consistently, however in
some cases that are prevalent in SQLAlchemy code it produces
too-long lines. The too-long lines will be resolved in the
following commit that will resolve all remaining flake8 issues
including shadowed builtins, long lines, import order, unused
imports, duplicate imports, and docstring issues.
Change-Id: I7eda77fed3d8e73df84b3651fd6cfcfe858d4dc9
Fixed bug where the use of an :class:`.Alias` object in a column
context would raise an argument error when it tried to group itself
into a parenthesized expression. Using :class:`.Alias` in this way
is not yet a fully supported API, however it applies to some end-user
recipes and may have a more prominent role in support of some
future Postgresql features.
Change-Id: I81717e30416e0350f08d1e022c3d84656e0a9735
Fixes: #3939
Fixed bug where setting up a single-table inh subclass of a joined-table
subclass which included an extra column would corrupt the foreign keys
collection of the mapped table, thereby interfering with the
initialization of relationships.
Change-Id: I04a0cf98fd456d12d5a5b9e77a46a01246969a63
Fixes: #3797
be properly typed as boolean in the result, and also would fail to be
anonymously aliased in a SELECT list as is the case with a
non-negated EXISTS construct.
fixes#3682
when the construct contains non-standard sql elements such as
returning, array index operations, or dialect-specific or custom
datatypes. a string is now returned in these cases rendering an
approximation of the construct (typically the postgresql-style
version of it) rather than raising an error. fixes#3631
- add within_group to top-level imports
- add eq_ignore_whitespace to sqlalchemy.testing imports
``<function> WITHIN GROUP (ORDER BY <criteria>)``, using the
method :class:`.FunctionElement.within_group`. A series of common
set-aggregate functions with return types derived from the set have
been added. This includes functions like :class:`.percentile_cont`,
:class:`.dense_rank` and others.
fixes#1370
- make sure we use func.name for all _literal_as_binds in functions.py
so we get consistent naming behavior for parameters.
such as :meth:`.Query.union` now handle the case where the embedded
SELECT statements need to be parenthesized due to the fact that they
include LIMIT, OFFSET and/or ORDER BY. These queries **do not work
on SQLite**, and will fail on that backend as they did before, but
should now work on all other backends.
fixes#2528
assign the proper result type of Boolean to the result mapping, and
instead would leak column types from within the query into the
result map. This issue exists in 0.9 and earlier as well, however
has less of an impact in those versions. In 1.0, due to #918
this becomes a regression in that we now rely upon the result mapping
to be very accurate, else we can assign result-type processors to
the wrong column. In all versions, this issue also has the effect
that a simple EXISTS will not apply the Boolean type handler, leading
to simple 1/0 values for backends without native boolean instead of
True/False. The fix includes that an EXISTS columns argument
will be anon-labeled like other column expressions; a similar fix is
implemented for pure-boolean expressions like ``not_(True())``.
fixes#3372
the sql package would fail to ``__repr__()`` successfully,
due to a missing ``description`` attribute that would then invoke
a recursion overflow when an internal AttributeError would then
re-invoke ``__repr__()``.
fixes#3195
we're now using; rework them fully so that their behavioral contract
is consistent regarding adapter.traverse() vs. adapter.columns[],
add a full suite of tests including advanced wrapping scenarios
previously only covered by test/orm/test_froms.py and
test/orm/inheritance/test_relationships.py
- identify several cases where label._order_by_label_clause would be
corrupted, e.g. due to adaption or annotation separately
- add full tests for #3148
Mike Bayer