"dbo.master", are now rendered in select() labels
with underscores for dots, i.e. "dbo_master_table_column".
This is a "friendly" label that behaves better
in result sets. [ticket:1428]
lazy load will fallback to the possibly cached query.get()
value, now works across join conditions where the two compared
types are not exactly the same class, but share the same
"affinity" - i.e. Integer and SmallInteger. Also allows
combinations of reflected and non-reflected types to work
with 0.5 style type reflection, such as PGText/Text (note 0.6
reflects types as their generic versions). [ticket:1556]
- types now support an "affinity comparison" operation, i.e.
that an Integer/SmallInteger are "compatible", or
a Text/String, PickleType/Binary, etc. Part of
[ticket:1556].
have native boolean support, will generate a CHECK
constraint "col IN (0, 1)" along with the int/smallint-
based column type. This can be switched off if
desired with create_constraint=False.
Note that MySQL has no native boolean *or* CHECK constraint
support so this feature isn't available on that platform.
[ticket:1589]
Uses a straight CheckConstraint with a generic expression. Preparing for boolean
constraint in [ticket:1589]
- CheckConstraint now accepts SQL expressions, though support for quoting of values
will be very limited. we don't want to get into formatting dates and such.
an error before passing to MySQL. Doesn't impact
CAST since VARCHAR is not allowed in MySQL CAST anyway,
the dialect renders CHAR/NCHAR in those cases.
[ticket:1252]
types to more intelligently determine float() vs. Decimal(),
[ticket:1567]
- since result processing is a hot issue of late, the DBAPI type
returned from cursor.description is certainly useful in cases like
these to determine an efficient result processor. There's likely
other result processors that can make use of it. But, backwards
incompat change to result_processor(). Happy major version number..
on all new connections, which allows all String/Text/etc.
types to skip the need to post-process bytestrings into
unicode (an expensive step due to its volume). Other
dialects which return unicode natively (pg8000, zxjdbc)
also skip unicode post-processing.
- String/Text/Unicode types now skip the unicode() check
on each result column value if the dialect has
detected the DBAPI as returning Python unicode objects
natively. This check is issued on first connect
using "SELECT CAST 'some text' AS VARCHAR(10)" or
equivalent, then checking if the returned object
is a Python unicode. This allows vast performance
increases for native-unicode DBAPIs, including
pysqlite/sqlite3, psycopg2, and pg8000.
method call counts when fetching columns that have no
type-level processing applied. Provides a 100% speed
improvement when fetching large result sets with no unicode
conversion. Many thanks to Elixir's Gaëtan de Menten
for this dramatic improvement ! [ticket:1586]
objects using names that match the keys of columns. These
bind parameters will circumvent the usual route to those
keys showing up in the VALUES or SET clause of the generated
SQL. [ticket:1579]
- deprecated PassiveDefault - use DefaultClause.
- the BINARY and MSBinary types now generate "BINARY" in all
cases. Omitting the "length" parameter will generate
"BINARY" with no length. Use BLOB to generate an unlengthed
binary column.
- the "quoting='quoted'" argument to MSEnum/ENUM is deprecated.
It's best to rely upon the automatic quoting.
- "shortname" attribute on bindparam() is removed.
- fold_equivalents flag on join is deprecated (will remain
until [ticket:1131] is implemented)
- "scalar" flag on select() is removed, use
select.as_scalar().
- 'transactional' flag on sessionmaker() and others is
removed. Use 'autocommit=True' to indicate 'transactional=False'.
- 'polymorphic_fetch' argument on mapper() is removed.
Loading can be controlled using the 'with_polymorphic'
option.
- 'select_table' argument on mapper() is removed. Use
'with_polymorphic=("*", <some selectable>)' for this
functionality.
- 'proxy' argument on synonym() is removed. This flag
did nothing throughout 0.5, as the "proxy generation"
behavior is now automatic.
- Passing a single list of elements to eagerload(),
eagerload_all(), contains_eager(), lazyload(),
defer(), and undefer() instead of multiple positional
-args is deprecated.
- Passing a single list of elements to query.order_by(),
query.group_by(), query.join(), or query.outerjoin()
instead of multiple positional *args is deprecated.
- query.iterate_instances() is removed. Use query.instances().
- Query.query_from_parent() is removed. Use the
sqlalchemy.orm.with_parent() function to produce a
"parent" clause, or alternatively query.with_parent().
- query._from_self() is removed, use query.from_self()
instead.
- the "comparator" argument to composite() is removed.
Use "comparator_factory".
- RelationProperty._get_join() is removed.
- the 'echo_uow' flag on Session is removed. Use
logging on the "sqlalchemy.orm.unitofwork" name.
- session.clear() is removed. use session.expunge_all().
- session.save(), session.update(), session.save_or_update()
are removed. Use session.add() and session.add_all().
- the "objects" flag on session.flush() remains deprecated.
- the "dont_load=True" flag on session.merge() is deprecated
in favor of "load=False".
- passing an InstanceState (internal SQLAlchemy state object) to
attributes.init_collection() or attributes.get_history() is
deprecated. These functions are public API and normally
expect a regular mapped object instance.
- the 'engine' parameter to declarative_base() is removed.
Use the 'bind' keyword argument.
sets require that all keys are present which are
present in the first bound parameter set. The structure
and behavior of an insert/update statement is very much
determined by the first parameter set, including which
defaults are going to fire off, and a minimum of
guesswork is performed with all the rest so that performance
is not impacted. For this reason defaults would otherwise
silently "fail" for missing parameters, so this is now guarded
against. [ticket:1566]
of this object has been simplified and moved into
ExecutionContext. Dialects which support sequences should
add a `fire_sequence()` method to their execution context
implementation. [ticket:1566]
to act justlike Oracle's NUMBER type. It is the primary
numeric type returned by table reflection and attempts
to return Decimal()/float/int based on the precision/scale
parameters. [ticket:885]
psycopg2 can't handle a bind parameter name of
%(foobar)s however and SQLA doesn't want to add overhead
just to treat that one non-existent use case.
[ticket:1279]
- MySQL: somewhat better support for % signs in table/column names;
MySQLdb can't handle % signs in SQL when executemany() is used,
and SQLA doesn't want to add overhead just to treat that one
non-existent use case. [ticket:1279]
- Removed an obscure feature of execute() (including connection,
engine, Session) whereby a bindparam() construct can be sent as
a key to the params dictionary. This usage is undocumented
and is at the core of an issue whereby the bindparam() object
created implicitly by a text() construct may have the same
hash value as a string placed in the params dictionary and
may result in an inappropriate match when computing the final
bind parameters. Internal checks for this condition would
add significant latency to the critical task of parameter
rendering, so the behavior is removed. This is a backwards
incompatible change for any application that may have been
using this feature, however the feature has never been
documented.
SQL clause matches the clause used by get(), but
contains some parameters hardcoded. Previously
the lazy strategy would fail with the get(). Ideally
get() would be used with the hardcoded parameters
but this would require further development.
[ticket:1357]
Mike Bayer