Fixed bug where the "simple many-to-one" condition that allows  lazy
loading to use get() from identity map would fail to be  invoked if the
primaryjoin of the relationship had multiple clauses separated by AND
which were not in the same order as that of the primary key columns
being compared in each clause. This ordering
difference occurs for a composite foreign key where the table-bound
columns on the referencing side were not in the same order in the .c
collection as the primary key columns on the referenced side....which
in turn occurs a lot if one is using declarative mixins and/or
declared_attr to set up columns.

Change-Id: I66cce74f614c04ed693dc0d58ac8c952b2f8ae54
Fixes: #3788

Raise a more descriptive exception / message when ClauseElement
or non-SQLAlchemy objects that are not "executable" are erroneously
passed to ``.execute()``; a new exception ObjectNotExecutableError
is raised consistently in all cases.

Change-Id: I2dd393121e2c7e5b6b9e40286a2f25670876e8e4
Fixes: #3786

Fixes: #3049
Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Change-Id: Ie572095c3e25f70a1e72e1af6858e5edd89fd25e
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/264

Fixed bug whereby passing a :func:`.text` construct to the
:meth:`.Query.group_by` method would raise an error, instead
of intepreting the object as a SQL fragment.

Change-Id: I5fc2f590b76508d52e23b5fa9cf037ddea8080c3
fixes: #3706

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

we're trying to hit columns without names yet and such, to suit the bug
right now just make it specific to FunctionElement

(cherry picked from commit 785224a92f39bd5bdd05bbc66f4dd79736abded5)

passed to :func:`.column_property`, so that if the same attribute
is referred to as a column expression twice the names are de-duped,
thus avoiding "ambiguous column" errors.   Previously, the
``.label(None)`` would need to be applied in order for the name
to be de-anonymized.
fixes #3663

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

method, and its interaction with result-row processing, now allows
the columns passed to the method to be positionally matched with the
result columns in the statement, rather than matching on name alone.
The advantage to this includes that when linking a textual SQL statement
to an ORM or Core table model, no system of labeling or de-duping of
common column names needs to occur, which also means there's no need
to worry about how label names match to ORM columns and so-forth.  In
addition, the :class:`.ResultProxy` has been further enhanced to
map column and string keys to a row with greater precision in some
cases.  fixes #3501
- reorganize the initialization of ResultMetaData for readability
and complexity; use the name "cursor_description", define the
task of "merging" cursor_description with compiled column information
as its own function, and also define "name extraction" as a separate task.
- fully change the name we use in the "ambiguous column" error to be the
actual name that was ambiguous, modify the C ext also