* ORM Insert now includes "bulk" mode that will run
essentially the same process as session.bulk_insert_mappings;
interprets the given list of values as ORM attributes for
key names
* ORM UPDATE has a similar feature, without RETURNING support,
for session.bulk_update_mappings
* Added support for upserts to do RETURNING ORM objects as well
* ORM UPDATE/DELETE with list of parameters + WHERE criteria
is a not implemented; use connection
* ORM UPDATE/DELETE defaults to "auto" synchronize_session;
use fetch if RETURNING is present, evaluate if not, as
"fetch" is much more efficient (no expired object SELECT problem)
and less error prone if RETURNING is available
UPDATE: howver this is inefficient! please continue to
use evaluate for simple cases, auto can move to fetch
if criteria not evaluable
* "Evaluate" criteria will now not preemptively
unexpire and SELECT attributes that were individually
expired. Instead, if evaluation of the criteria indicates that
the necessary attrs were expired, we expire the object
completely (delete) or expire the SET attrs unconditionally
(update). This keeps the object in the same unloaded state
where it will refresh those attrs on the next pass, for
this generally unusual case. (originally #5664)
* Core change! update/delete rowcount comes from len(rows)
if RETURNING was used. SQLite at least otherwise did not
support this. adjusted test_rowcount accordingly
* ORM DELETE with a list of parameters at all is also a not
implemented as this would imply "bulk", and there is no
bulk_delete_mappings (could be, but we dont have that)
* ORM insert().values() with single or multi-values translates
key names based on ORM attribute names
* ORM returning() implemented for insert, update, delete;
explcit returning clauses now interpret rows in an ORM
context, with support for qualifying loader options as well
* session.bulk_insert_mappings() assigns polymorphic identity
if not set.
* explicit RETURNING + synchronize_session='fetch' is now
supported with UPDATE and DELETE.
* expanded return_defaults() to work with DELETE also.
* added support for composite attributes to be present
in the dictionaries used by bulk_insert_mappings and
bulk_update_mappings, which is also the new ORM bulk
insert/update feature, that will expand the composite
values into their individual mapped attributes the way they'd
be on a mapped instance.
* bulk UPDATE supports "synchronize_session=evaluate", is the
default. this does not apply to session.bulk_update_mappings,
just the new version
* both bulk UPDATE and bulk INSERT, the latter with or without
RETURNING, support *heterogenous* parameter sets.
session.bulk_insert/update_mappings did this, so this feature
is maintained. now cursor result can be both horizontally
and vertically spliced :)
This is now a long story with a lot of options, which in
itself is a problem to be able to document all of this
in some way that makes sense. raising exceptions for
use cases we haven't supported is pretty important here
too, the tradition of letting unsupported things just not work
is likely not a good idea at this point, though there
are still many cases that aren't easily avoidable
Fixes: #8360
Fixes: #7864
Fixes: #7865
Change-Id: Idf28379f8705e403a3c6a937f6a798a042ef2540