form of a some expressions when referring to the ``.c`` collection on a ``select()`` construct, but the ``str()`` form isn't available since the element relies on dialect-specific compilation constructs, notably the ``__getitem__()`` operator as used with a Postgresql ``ARRAY`` element. The fix also adds a new exception class :class:`.UnsupportedCompilationError` which is raised in those cases where a compiler is asked to compile something it doesn't know how to. Also in 0.8.3. [ticket:2780]
:meth:`.Insert.from_select`. Given a list of columns and a selectable, renders ``INSERT INTO (table) (columns) SELECT ..``. While this feature is highlighted as part of 0.9 it is also backported to 0.8.3. [ticket:722] - The :func:`.update`, :func:`.insert`, and :func:`.delete` constructs will now interpret ORM entities as FROM clauses to be operated upon, in the same way that select() already does. Also in 0.8.3.
table is a SELECT with its own bound parameters, where the positioning of the bound parameters would be reversed versus the statement itself when using MySQL's special syntax. [ticket:2768]
- add support for correlations to propagate all the way in; because correlations require context now, need to make sure a select enclosure of any level takes effect any number of levels deep. - fix what we said correlate_except() was supposed to do when we first released #2668 - "the FROM clause is left intact if the correlated SELECT is not used in the context of an enclosing SELECT..." - it was not considering the "existing_froms" collection at all, and prohibited additional FROMs from being placed in an any() or has(). - add test for multilevel any() - lots of docs, including glossary entries as we really need to define "WHERE clause", "columns clause" etc. so that we can explain correlation better - based on the insight that a SELECT can correlate anything that ultimately came from an enclosing SELECT that links to this one via WHERE/columns/HAVING/ORDER BY, have the compiler keep track of the FROM lists that correspond in this way, link it to the asfrom flag, so that we send to _get_display_froms() the exact list of candidate FROMs to correlate. no longer need any asfrom logic in the Select() itself - preserve 0.8.1's behavior for correlation when no correlate options are given, not to mention 0.7 and prior's behavior of not propagating implicit correlation more than one level.. this is to reduce surprises/hard-to-debug situations when a user isn't trying to correlate anything.
target :class:`.Column` has been reworked to be as immediate as possible, based on the moment that the target :class:`.Column` is associated with the same :class:`.MetaData` as this :class:`.ForeignKey`, rather than waiting for the first time a join is constructed, or similar. This along with other improvements allows earlier detection of some foreign key configuration issues. Also included here is a rework of the type-propagation system, so that it should be reliable now to set the type as ``None`` on any :class:`.Column` that refers to another via :class:`.ForeignKey` - the type will be copied from the target column as soon as that other column is associated, and now works for composite foreign keys as well. [ticket:1765]
called :attr:`.TypeDecorator.coerce_to_is_types`, to make it easier to control how comparisons using ``==`` or ``!=`` to ``None`` and boolean types goes about producing an ``IS`` expression, or a plain equality expression with a bound parameter. [ticket:2744]
- docs docs docs
fetched when joining/joinedloading across a many-to-many relationship to a single-table-inheriting subclass with a specific discriminator value, due to "secondary" rows that would come back. The "secondary" and right-side tables are now inner joined inside of parenthesis for all ORM joins on many-to-many relationships so that the left->right join can accurately filtered. [ticket:2369]