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Mike Bayer 5ab558004c - The beaker_caching example has been reorgnized 
such that the Session, cache manager,
declarative_base are part of environment, and
custom cache code is portable and now within
"caching_query.py".  This allows the example to
be easier to "drop in" to existing projects.
2010-07-21 16:19:08 -04:00

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-*- coding: utf-8; fill-column: 68 -*-
=======
CHANGES
=======
0.6.4
=====
- sql
- Changed the scheme used to generate truncated
"auto" index names when using the "index=True"
flag on Column. The truncation only takes
place with the auto-generated name, not one
that is user-defined (an error would be
raised instead), and the truncation scheme
itself is now based on a fragment of an md5
hash of the identifier name, so that multiple
indexes on columns with similar names still
have unique names. [ticket:1855]
- examples
- The beaker_caching example has been reorgnized
such that the Session, cache manager,
declarative_base are part of environment, and
custom cache code is portable and now within
"caching_query.py". This allows the example to
be easier to "drop in" to existing projects.
0.6.3
=====
- orm
- Removed errant many-to-many load in unitofwork
which triggered unnecessarily on expired/unloaded
collections. This load now takes place only if
passive_updates is False and the parent primary
key has changed, or if passive_deletes is False
and a delete of the parent has occurred.
[ticket:1845]
- Column-entities (i.e. query(Foo.id)) copy their
state more fully when queries are derived from
themselves + a selectable (i.e. from_self(),
union(), etc.), so that join() and such have the
correct state to work from. [ticket:1853]
- Fixed bug where Query.join() would fail if
querying a non-ORM column then joining without
an on clause when a FROM clause is already
present, now raises a checked exception the
same way it does when the clause is not
present. [ticket:1853]
- Improved the check for an "unmapped class",
including the case where the superclass is mapped
but the subclass is not. Any attempts to access
cls._sa_class_manager.mapper now raise
UnmappedClassError(). [ticket:1142]
- Added "column_descriptions" accessor to Query,
returns a list of dictionaries containing
naming/typing information about the entities
the Query will return. Can be helpful for
building GUIs on top of ORM queries.
- mysql
- The _extract_error_code() method now works
correctly with each MySQL dialect (
MySQL-python, OurSQL, MySQL-Connector-Python,
PyODBC). Previously,
the reconnect logic would fail for OperationalError
conditions, however since MySQLdb and OurSQL
have their own reconnect feature, there was no
symptom for these drivers here unless one
watched the logs. [ticket:1848]
- oracle
- More tweaks to cx_oracle Decimal handling.
"Ambiguous" numerics with no decimal place
are coerced to int at the connection handler
level. The advantage here is that ints
come back as ints without SQLA type
objects being involved and without needless
conversion to Decimal first.
Unfortunately, some exotic subquery cases
can even see different types between
individual result rows, so the Numeric
handler, when instructed to return Decimal,
can't take full advantage of "native decimal"
mode and must run isinstance() on every value
to check if its Decimal already. Reopen of
[ticket:1840]
0.6.2
=====
- orm
- Query.join() will check for a call of the
form query.join(target, clause_expression),
i.e. missing the tuple, and raise an informative
error message that this is the wrong calling form.
- Fixed bug regarding flushes on self-referential
bi-directional many-to-many relationships, where
two objects made to mutually reference each other
in one flush would fail to insert a row for both
sides. Regression from 0.5. [ticket:1824]
- the post_update feature of relationship() has been
reworked architecturally to integrate more closely
with the new 0.6 unit of work. The motivation
for the change is so that multiple "post update"
calls, each affecting different foreign key
columns of the same row, are executed in a single
UPDATE statement, rather than one UPDATE
statement per column per row. Multiple row
updates are also batched into executemany()s as
possible, while maintaining consistent row ordering.
- Query.statement, Query.subquery(), etc. now transfer
the values of bind parameters, i.e. those specified
by query.params(), into the resulting SQL expression.
Previously the values would not be transferred
and bind parameters would come out as None.
- Subquery-eager-loading now works with Query objects
which include params(), as well as get() Queries.
- Can now call make_transient() on an instance that
is referenced by parent objects via many-to-one,
without the parent's foreign key value getting
temporarily set to None - this was a function
of the "detect primary key switch" flush handler.
It now ignores objects that are no longer
in the "persistent" state, and the parent's
foreign key identifier is left unaffected.
- query.order_by() now accepts False, which cancels
any existing order_by() state on the Query, allowing
subsequent generative methods to be called which do
not support ORDER BY. This is not the same as the
already existing feature of passing None, which
suppresses any existing order_by() settings, including
those configured on the mapper. False will make it
as though order_by() was never called, while
None is an active setting.
- An instance which is moved to "transient", has
an incomplete or missing set of primary key
attributes, and contains expired attributes, will
raise an InvalidRequestError if an expired attribute
is accessed, instead of getting a recursion overflow.
- The make_transient() function is now in the generated
documentation.
- make_transient() removes all "loader" callables from
the state being made transient, removing any
"expired" state - all unloaded attributes reset back
to undefined, None/empty on access.
- sql
- The warning emitted by the Unicode and String types
with convert_unicode=True no longer embeds the actual
value passed. This so that the Python warning
registry does not continue to grow in size, the warning
is emitted once as per the warning filter settings,
and large string values don't pollute the output.
[ticket:1822]
- Fixed bug that would prevent overridden clause
compilation from working for "annotated" expression
elements, which are often generated by the ORM.
- The argument to "ESCAPE" of a LIKE operator or similar
is passed through render_literal_value(), which may
implement escaping of backslashes. [ticket:1400]
- Fixed bug in Enum type which blew away native_enum
flag when used with TypeDecorators or other adaption
scenarios.
- Inspector hits bind.connect() when invoked to ensure
initialize has been called. the internal name ".conn"
is changed to ".bind", since that's what it is.
- Modified the internals of "column annotation" such that
a custom Column subclass can safely override
_constructor to return Column, for the purposes of
making "configurational" column classes that aren't
involved in proxying, etc.
- Column.copy() takes along the "unique" attribute
among others, fixes [ticket:1829] regarding declarative
mixins
- postgresql
- render_literal_value() is overridden which escapes
backslashes, currently applies to the ESCAPE clause
of LIKE and similar expressions.
Ultimately this will have to detect the value of
"standard_conforming_strings" for full behavior.
[ticket:1400]
- Won't generate "CREATE TYPE" / "DROP TYPE" if
using types.Enum on a PG version prior to 8.3 -
the supports_native_enum flag is fully
honored. [ticket:1836]
- mysql
- MySQL dialect doesn't emit CAST() for MySQL version
detected < 4.0.2. This allows the unicode
check on connect to proceed. [ticket:1826]
- MySQL dialect now detects NO_BACKSLASH_ESCAPES sql
mode, in addition to ANSI_QUOTES.
- render_literal_value() is overridden which escapes
backslashes, currently applies to the ESCAPE clause
of LIKE and similar expressions. This behavior
is derived from detecting the value of
NO_BACKSLASH_ESCAPES. [ticket:1400]
- oracle:
- Fixed ora-8 compatibility flags such that they
don't cache a stale value from before the first
database connection actually occurs. [ticket:1819]
- Oracle's "native decimal" metadata begins to return
ambiguous typing information about numerics
when columns are embedded in subqueries as well
as when ROWNUM is consulted with subqueries, as we
do for limit/offset. We've added these ambiguous
conditions to the cx_oracle "convert to Decimal()"
handler, so that we receive numerics as Decimal
in more cases instead of as floats. These are
then converted, if requested, into Integer
or Float, or otherwise kept as the lossless
Decimal [ticket:1840].
- mssql
- If server_version_info is outside the usual
range of (8, ), (9, ), (10, ), a warning is emitted
which suggests checking that the FreeTDS version
configuration is using 7.0 or 8.0, not 4.2.
[ticket:1825]
- firebird
- Fixed incorrect signature in do_execute(), error
introduced in 0.6.1. [ticket:1823]
- Firebird dialect adds CHAR, VARCHAR types which
accept a "charset" flag, to support Firebird
"CHARACTER SET" clause. [ticket:1813]
- declarative
- Added support for @classproperty to provide
any kind of schema/mapping construct from a
declarative mixin, including columns with foreign
keys, relationships, column_property, deferred.
This solves all such issues on declarative mixins.
An error is raised if any MapperProperty subclass
is specified on a mixin without using @classproperty.
[ticket:1751] [ticket:1796] [ticket:1805]
- a mixin class can now define a column that matches
one which is present on a __table__ defined on a
subclass. It cannot, however, define one that is
not present in the __table__, and the error message
here now works. [ticket:1821]
- compiler extension
- The 'default' compiler is automatically copied over
when overriding the compilation of a built in
clause construct, so no KeyError is raised if the
user-defined compiler is specific to certain
backends and compilation for a different backend
is invoked. [ticket:1838]
- documentation
- Added documentation for the Inspector. [ticket:1820]
- Fixed @memoized_property and @memoized_instancemethod
decorators so that Sphinx documentation picks up
these attributes and methods, such as
ResultProxy.inserted_primary_key. [ticket:1830]
0.6.1
=====
- orm
- Fixed regression introduced in 0.6.0 involving improper
history accounting on mutable attributes. [ticket:1782]
- Fixed regression introduced in 0.6.0 unit of work refactor
that broke updates for bi-directional relationship()
with post_update=True. [ticket:1807]
- session.merge() will not expire attributes on the returned
instance if that instance is "pending". [ticket:1789]
- fixed __setstate__ method of CollectionAdapter to not
fail during deserialize where parent InstanceState not
yet unserialized. [ticket:1802]
- Added internal warning in case an instance without a
full PK happened to be expired and then was asked
to refresh. [ticket:1797]
- Added more aggressive caching to the mapper's usage of
UPDATE, INSERT, and DELETE expressions. Assuming the
statement has no per-object SQL expressions attached,
the expression objects are cached by the mapper after
the first create, and their compiled form is stored
persistently in a cache dictionary for the duration of
the related Engine. The cache is an LRUCache for the
rare case that a mapper receives an extremely
high number of different column patterns as UPDATEs.
- sql
- expr.in_() now accepts a text() construct as the argument.
Grouping parenthesis are added automatically, i.e. usage
is like `col.in_(text("select id from table"))`.
[ticket:1793]
- Columns of _Binary type (i.e. LargeBinary, BLOB, etc.)
will coerce a "basestring" on the right side into a
_Binary as well so that required DBAPI processing
takes place.
- Added table.add_is_dependent_on(othertable), allows manual
placement of dependency rules between two Table objects
for use within create_all(), drop_all(), sorted_tables.
[ticket:1801]
- Fixed bug that prevented implicit RETURNING from functioning
properly with composite primary key that contained zeroes.
[ticket:1778]
- Fixed errant space character when generating ADD CONSTRAINT
for a named UNIQUE constraint.
- Fixed "table" argument on constructor of ForeginKeyConstraint
[ticket:1571]
- Fixed bug in connection pool cursor wrapper whereby if a
cursor threw an exception on close(), the logging of the
message would fail. [ticket:1786]
- the _make_proxy() method of ColumnClause and Column now use
self.__class__ to determine the class of object to be returned
instead of hardcoding to ColumnClause/Column, making it slightly
easier to produce specific subclasses of these which work in
alias/subquery situations.
- func.XXX() doesn't inadvertently resolve to non-Function
classes (e.g. fixes func.text()). [ticket:1798]
- engines
- Fixed building the C extensions on Python 2.4. [ticket:1781]
- Pool classes will reuse the same "pool_logging_name" setting
after a dispose() occurs.
- Engine gains an "execution_options" argument and
update_execution_options() method, which will apply to
all connections generated by this engine.
- mysql
- func.sysdate() emits "SYSDATE()", i.e. with the ending
parenthesis, on MySQL. [ticket:1794]
- sqlite
- Fixed concatenation of constraints when "PRIMARY KEY"
constraint gets moved to column level due to SQLite
AUTOINCREMENT keyword being rendered. [ticket:1812]
- oracle
- Added a check for cx_oracle versions lower than version 5,
in which case the incompatible "output type handler" won't
be used. This will impact decimal accuracy and some
unicode handling issues. [ticket:1775]
- Fixed use_ansi=False mode, which was producing broken
WHERE clauses in pretty much all cases. [ticket:1790]
- Re-established support for Oracle 8 with cx_oracle,
including that use_ansi is set to False automatically,
NVARCHAR2 and NCLOB are not rendered for Unicode,
"native unicode" check doesn't fail, cx_oracle
"native unicode" mode is disabled, VARCHAR() is emitted
with bytes count instead of char count. [ticket:1808]
- oracle_xe 5 doesn't accept a Python unicode object in
its connect string in normal Python 2.x mode - so we coerce
to str() directly. non-ascii characters aren't supported
in connect strings here since we don't know what encoding
we could use. [ticket:1670]
- FOR UPDATE is emitted in the syntactically correct position
when limit/offset is used, i.e. the ROWNUM subquery.
However, Oracle can't really handle FOR UPDATE with ORDER BY
or with subqueries, so its still not very usable, but at
least SQLA gets the SQL past the Oracle parser.
[ticket:1815]
- firebird
- Added a label to the query used within has_table() and
has_sequence() to work with older versions of Firebird
that don't provide labels for result columns. [ticket:1521]
- Added integer coercion to the "type_conv" attribute when
passed via query string, so that it is properly interpreted
by Kinterbasdb. [ticket:1779]
- Added 'connection shutdown' to the list of exception strings
which indicate a dropped connection. [ticket:1646]
- sqlsoup
- the SqlSoup constructor accepts a `base` argument which specifies
the base class to use for mapped classes, the default being
`object`. [ticket:1783]
0.6.0
=====
- orm
- Unit of work internals have been rewritten. Units of work
with large numbers of objects interdependent objects
can now be flushed without recursion overflows
as there is no longer reliance upon recursive calls
[ticket:1081]. The number of internal structures now stays
constant for a particular session state, regardless of
how many relationships are present on mappings. The flow
of events now corresponds to a linear list of steps,
generated by the mappers and relationships based on actual
work to be done, filtered through a single topological sort
for correct ordering. Flush actions are assembled using
far fewer steps and less memory. [ticket:1742]
- Along with the UOW rewrite, this also removes an issue
introduced in 0.6beta3 regarding topological cycle detection
for units of work with long dependency cycles. We now use
an algorithm written by Guido (thanks Guido!).
- one-to-many relationships now maintain a list of positive
parent-child associations within the flush, preventing
previous parents marked as deleted from cascading a
delete or NULL foreign key set on those child objects,
despite the end-user not removing the child from the old
association. [ticket:1764]
- A collection lazy load will switch off default
eagerloading on the reverse many-to-one side, since
that loading is by definition unnecessary. [ticket:1495]
- Session.refresh() now does an equivalent expire()
on the given instance first, so that the "refresh-expire"
cascade is propagated. Previously, refresh() was
not affected in any way by the presence of "refresh-expire"
cascade. This is a change in behavior versus that
of 0.6beta2, where the "lockmode" flag passed to refresh()
would cause a version check to occur. Since the instance
is first expired, refresh() always upgrades the object
to the most recent version.
- The 'refresh-expire' cascade, when reaching a pending object,
will expunge the object if the cascade also includes
"delete-orphan", or will simply detach it otherwise.
[ticket:1754]
- id(obj) is no longer used internally within topological.py,
as the sorting functions now require hashable objects
only. [ticket:1756]
- The ORM will set the docstring of all generated descriptors
to None by default. This can be overridden using 'doc'
(or if using Sphinx, attribute docstrings work too).
- Added kw argument 'doc' to all mapper property callables
as well as Column(). Will assemble the string 'doc' as
the '__doc__' attribute on the descriptor.
- Usage of version_id_col on a backend that supports
cursor.rowcount for execute() but not executemany() now works
when a delete is issued (already worked for saves, since those
don't use executemany()). For a backend that doesn't support
cursor.rowcount at all, a warning is emitted the same
as with saves. [ticket:1761]
- The ORM now short-term caches the "compiled" form of
insert() and update() constructs when flushing lists of
objects of all the same class, thereby avoiding redundant
compilation per individual INSERT/UPDATE within an
individual flush() call.
- internal getattr(), setattr(), getcommitted() methods
on ColumnProperty, CompositeProperty, RelationshipProperty
have been underscored (i.e. are private), signature has
changed.
- engines
- The C extension now also works with DBAPIs which use custom
sequences as row (and not only tuples). [ticket:1757]
- sql
- Restored some bind-labeling logic from 0.5 which ensures
that tables with column names that overlap another column
of the form "<tablename>_<columnname>" won't produce
errors if column._label is used as a bind name during
an UPDATE. Test coverage which wasn't present in 0.5
has been added. [ticket:1755]
- somejoin.select(fold_equivalents=True) is no longer
deprecated, and will eventually be rolled into a more
comprehensive version of the feature for [ticket:1729].
- the Numeric type raises an *enormous* warning when expected
to convert floats to Decimal from a DBAPI that returns floats.
This includes SQLite, Sybase, MS-SQL. [ticket:1759]
- Fixed an error in expression typing which caused an endless
loop for expressions with two NULL types.
- Fixed bug in execution_options() feature whereby the existing
Transaction and other state information from the parent
connection would not be propagated to the sub-connection.
- Added new 'compiled_cache' execution option. A dictionary
where Compiled objects will be cached when the Connection
compiles a clause expression into a dialect- and parameter-
specific Compiled object. It is the user's responsibility to
manage the size of this dictionary, which will have keys
corresponding to the dialect, clause element, the column
names within the VALUES or SET clause of an INSERT or UPDATE,
as well as the "batch" mode for an INSERT or UPDATE statement.
- Added get_pk_constraint() to reflection.Inspector, similar
to get_primary_keys() except returns a dict that includes the
name of the constraint, for supported backends (PG so far).
[ticket:1769]
- Table.create() and Table.drop() no longer apply metadata-
level create/drop events. [ticket:1771]
- ext
- the compiler extension now allows @compiles decorators
on base classes that extend to child classes, @compiles
decorators on child classes that aren't broken by a
@compiles decorator on the base class.
- Declarative will raise an informative error message
if a non-mapped class attribute is referenced in the
string-based relationship() arguments.
- Further reworked the "mixin" logic in declarative to
additionally allow __mapper_args__ as a @classproperty
on a mixin, such as to dynamically assign polymorphic_identity.
- postgresql
- Postgresql now reflects sequence names associated with
SERIAL columns correctly, after the name of of the sequence
has been changed. Thanks to Kumar McMillan for the patch.
[ticket:1071]
- Repaired missing import in psycopg2._PGNumeric type when
unknown numeric is received.
- psycopg2/pg8000 dialects now aware of REAL[], FLOAT[],
DOUBLE_PRECISION[], NUMERIC[] return types without
raising an exception.
- Postgresql reflects the name of primary key constraints,
if one exists. [ticket:1769]
- oracle
- Now using cx_oracle output converters so that the
DBAPI returns natively the kinds of values we prefer:
- NUMBER values with positive precision + scale convert
to cx_oracle.STRING and then to Decimal. This
allows perfect precision for the Numeric type when
using cx_oracle. [ticket:1759]
- STRING/FIXED_CHAR now convert to unicode natively.
SQLAlchemy's String types then don't need to
apply any kind of conversions.
- firebird
- The functionality of result.rowcount can be disabled on a
per-engine basis by setting 'enable_rowcount=False'
on create_engine(). Normally, cursor.rowcount is called
after any UPDATE or DELETE statement unconditionally,
because the cursor is then closed and Firebird requires
an open cursor in order to get a rowcount. This
call is slightly expensive however so it can be disabled.
To re-enable on a per-execution basis, the
'enable_rowcount=True' execution option may be used.
- examples
- Updated attribute_shard.py example to use a more robust
method of searching a Query for binary expressions which
compare columns against literal values.
0.6beta3
========
- orm
- Major feature: Added new "subquery" loading capability to
relationship(). This is an eager loading option which
generates a second SELECT for each collection represented
in a query, across all parents at once. The query
re-issues the original end-user query wrapped in a subquery,
applies joins out to the target collection, and loads
all those collections fully in one result, similar to
"joined" eager loading but using all inner joins and not
re-fetching full parent rows repeatedly (as most DBAPIs seem
to do, even if columns are skipped). Subquery loading is
available at mapper config level using "lazy='subquery'" and
at the query options level using "subqueryload(props..)",
"subqueryload_all(props...)". [ticket:1675]
- To accomodate the fact that there are now two kinds of eager
loading available, the new names for eagerload() and
eagerload_all() are joinedload() and joinedload_all(). The
old names will remain as synonyms for the foreseeable future.
- The "lazy" flag on the relationship() function now accepts
a string argument for all kinds of loading: "select", "joined",
"subquery", "noload" and "dynamic", where the default is now
"select". The old values of True/
False/None still retain their usual meanings and will remain
as synonyms for the foreseeable future.
- Added with_hint() method to Query() construct. This calls
directly down to select().with_hint() and also accepts
entities as well as tables and aliases. See with_hint() in the
SQL section below. [ticket:921]
- Fixed bug in Query whereby calling q.join(prop).from_self(...).
join(prop) would fail to render the second join outside the
subquery, when joining on the same criterion as was on the
inside.
- Fixed bug in Query whereby the usage of aliased() constructs
would fail if the underlying table (but not the actual alias)
were referenced inside the subquery generated by
q.from_self() or q.select_from().
- Fixed bug which affected all eagerload() and similar options
such that "remote" eager loads, i.e. eagerloads off of a lazy
load such as query(A).options(eagerload(A.b, B.c))
wouldn't eagerload anything, but using eagerload("b.c") would
work fine.
- Query gains an add_columns(*columns) method which is a multi-
version of add_column(col). add_column(col) is future
deprecated.
- Query.join() will detect if the end result will be
"FROM A JOIN A", and will raise an error if so.
- Query.join(Cls.propname, from_joinpoint=True) will check more
carefully that "Cls" is compatible with the current joinpoint,
and act the same way as Query.join("propname", from_joinpoint=True)
in that regard.
- sql
- Added with_hint() method to select() construct. Specify
a table/alias, hint text, and optional dialect name, and
"hints" will be rendered in the appropriate place in the
statement. Works for Oracle, Sybase, MySQL. [ticket:921]
- Fixed bug introduced in 0.6beta2 where column labels would
render inside of column expressions already assigned a label.
[ticket:1747]
- postgresql
- The psycopg2 dialect will log NOTICE messages via the
"sqlalchemy.dialects.postgresql" logger name.
[ticket:877]
- the TIME and TIMESTAMP types are now availble from the
postgresql dialect directly, which add the PG-specific
argument 'precision' to both. 'precision' and
'timezone' are correctly reflected for both TIME and
TIMEZONE types. [ticket:997]
- mysql
- No longer guessing that TINYINT(1) should be BOOLEAN
when reflecting - TINYINT(1) is returned. Use Boolean/
BOOLEAN in table definition to get boolean conversion
behavior. [ticket:1752]
- oracle
- The Oracle dialect will issue VARCHAR type definitions
using character counts, i.e. VARCHAR2(50 CHAR), so that
the column is sized in terms of characters and not bytes.
Column reflection of character types will also use
ALL_TAB_COLUMNS.CHAR_LENGTH instead of
ALL_TAB_COLUMNS.DATA_LENGTH. Both of these behaviors take
effect when the server version is 9 or higher - for
version 8, the old behaviors are used. [ticket:1744]
- declarative
- Using a mixin won't break if the mixin implements an
unpredictable __getattribute__(), i.e. Zope interfaces.
[ticket:1746]
- Using @classdecorator and similar on mixins to define
__tablename__, __table_args__, etc. now works if
the method references attributes on the ultimate
subclass. [ticket:1749]
- relationships and columns with foreign keys aren't
allowed on declarative mixins, sorry. [ticket:1751]
- ext
- The sqlalchemy.orm.shard module now becomes an extension,
sqlalchemy.ext.horizontal_shard. The old import
works with a deprecation warning.
0.6beta2
========
- py3k
- Improved the installation/test setup regarding Python 3,
now that Distribute runs on Py3k. distribute_setup.py
is now included. See README.py3k for Python 3 installation/
testing instructions.
- orm
- The official name for the relation() function is now
relationship(), to eliminate confusion over the relational
algebra term. relation() however will remain available
in equal capacity for the foreseeable future. [ticket:1740]
- Added "version_id_generator" argument to Mapper, this is a
callable that, given the current value of the "version_id_col",
returns the next version number. Can be used for alternate
versioning schemes such as uuid, timestamps. [ticket:1692]
- added "lockmode" kw argument to Session.refresh(), will
pass through the string value to Query the same as
in with_lockmode(), will also do version check for a
version_id_col-enabled mapping.
- Fixed bug whereby calling query(A).join(A.bs).add_entity(B)
in a joined inheritance scenario would double-add B as a
target and produce an invalid query. [ticket:1188]
- Fixed bug in session.rollback() which involved not removing
formerly "pending" objects from the session before
re-integrating "deleted" objects, typically occured with
natural primary keys. If there was a primary key conflict
between them, the attach of the deleted would fail
internally. The formerly "pending" objects are now expunged
first. [ticket:1674]
- Removed a lot of logging that nobody really cares about,
logging that remains will respond to live changes in the
log level. No significant overhead is added. [ticket:1719]
- Fixed bug in session.merge() which prevented dict-like
collections from merging.
- session.merge() works with relations that specifically
don't include "merge" in their cascade options - the target
is ignored completely.
- session.merge() will not expire existing scalar attributes
on an existing target if the target has a value for that
attribute, even if the incoming merged doesn't have
a value for the attribute. This prevents unnecessary loads
on existing items. Will still mark the attr as expired
if the destination doesn't have the attr, though, which
fulfills some contracts of deferred cols. [ticket:1681]
- The "allow_null_pks" flag is now called "allow_partial_pks",
defaults to True, acts like it did in 0.5 again. Except,
it also is implemented within merge() such that a SELECT
won't be issued for an incoming instance with partially
NULL primary key if the flag is False. [ticket:1680]
- Fixed bug in 0.6-reworked "many-to-one" optimizations
such that a many-to-one that is against a non-primary key
column on the remote table (i.e. foreign key against a
UNIQUE column) will pull the "old" value in from the
database during a change, since if it's in the session
we will need it for proper history/backref accounting,
and we can't pull from the local identity map on a
non-primary key column. [ticket:1737]
- fixed internal error which would occur if calling has()
or similar complex expression on a single-table inheritance
relation(). [ticket:1731]
- query.one() no longer applies LIMIT to the query, this to
ensure that it fully counts all object identities present
in the result, even in the case where joins may conceal
multiple identities for two or more rows. As a bonus,
one() can now also be called with a query that issued
from_statement() to start with since it no longer modifies
the query. [ticket:1688]
- query.get() now returns None if queried for an identifier
that is present in the identity map with a different class
than the one requested, i.e. when using polymorphic loading.
[ticket:1727]
- A major fix in query.join(), when the "on" clause is an
attribute of an aliased() construct, but there is already
an existing join made out to a compatible target, query properly
joins to the right aliased() construct instead of sticking
onto the right side of the existing join. [ticket:1706]
- Slight improvement to the fix for [ticket:1362] to not issue
needless updates of the primary key column during a so-called
"row switch" operation, i.e. add + delete of two objects
with the same PK.
- Now uses sqlalchemy.orm.exc.DetachedInstanceError when an
attribute load or refresh action fails due to object
being detached from any Session. UnboundExecutionError
is specific to engines bound to sessions and statements.
- Query called in the context of an expression will render
disambiguating labels in all cases. Note that this does
not apply to the existing .statement and .subquery()
accessor/method, which still honors the .with_labels()
setting that defaults to False.
- Query.union() retains disambiguating labels within the
returned statement, thus avoiding various SQL composition
errors which can result from column name conflicts.
[ticket:1676]
- Fixed bug in attribute history that inadvertently invoked
__eq__ on mapped instances.
- Some internal streamlining of object loading grants a
small speedup for large results, estimates are around
10-15%. Gave the "state" internals a good solid
cleanup with less complexity, datamembers,
method calls, blank dictionary creates.
- Documentation clarification for query.delete()
[ticket:1689]
- Fixed cascade bug in many-to-one relation() when attribute
was set to None, introduced in r6711 (cascade deleted
items into session during add()).
- Calling query.order_by() or query.distinct() before calling
query.select_from(), query.with_polymorphic(), or
query.from_statement() raises an exception now instead of
silently dropping those criterion. [ticket:1736]
- query.scalar() now raises an exception if more than one
row is returned. All other behavior remains the same.
[ticket:1735]
- Fixed bug which caused "row switch" logic, that is an
INSERT and DELETE replaced by an UPDATE, to fail when
version_id_col was in use. [ticket:1692]
- sql
- join() will now simulate a NATURAL JOIN by default. Meaning,
if the left side is a join, it will attempt to join the right
side to the rightmost side of the left first, and not raise
any exceptions about ambiguous join conditions if successful
even if there are further join targets across the rest of
the left. [ticket:1714]
- The most common result processors conversion function were
moved to the new "processors" module. Dialect authors are
encouraged to use those functions whenever they correspond
to their needs instead of implementing custom ones.
- SchemaType and subclasses Boolean, Enum are now serializable,
including their ddl listener and other event callables.
[ticket:1694] [ticket:1698]
- Some platforms will now interpret certain literal values
as non-bind parameters, rendered literally into the SQL
statement. This to support strict SQL-92 rules that are
enforced by some platforms including MS-SQL and Sybase.
In this model, bind parameters aren't allowed in the
columns clause of a SELECT, nor are certain ambiguous
expressions like "?=?". When this mode is enabled, the base
compiler will render the binds as inline literals, but only across
strings and numeric values. Other types such as dates
will raise an error, unless the dialect subclass defines
a literal rendering function for those. The bind parameter
must have an embedded literal value already or an error
is raised (i.e. won't work with straight bindparam('x')).
Dialects can also expand upon the areas where binds are not
accepted, such as within argument lists of functions
(which don't work on MS-SQL when native SQL binding is used).
- Added "unicode_errors" parameter to String, Unicode, etc.
Behaves like the 'errors' keyword argument to
the standard library's string.decode() functions. This flag
requires that `convert_unicode` is set to `"force"` - otherwise,
SQLAlchemy is not guaranteed to handle the task of unicode
conversion. Note that this flag adds significant performance
overhead to row-fetching operations for backends that already
return unicode objects natively (which most DBAPIs do). This
flag should only be used as an absolute last resort for reading
strings from a column with varied or corrupted encodings,
which only applies to databases that accept invalid encodings
in the first place (i.e. MySQL. *not* PG, Sqlite, etc.)
- Added math negation operator support, -x.
- FunctionElement subclasses are now directly executable the
same way any func.foo() construct is, with automatic
SELECT being applied when passed to execute().
- The "type" and "bind" keyword arguments of a func.foo()
construct are now local to "func." constructs and are
not part of the FunctionElement base class, allowing
a "type" to be handled in a custom constructor or
class-level variable.
- Restored the keys() method to ResultProxy.
- The type/expression system now does a more complete job
of determining the return type from an expression
as well as the adaptation of the Python operator into
a SQL operator, based on the full left/right/operator
of the given expression. In particular
the date/time/interval system created for Postgresql
EXTRACT in [ticket:1647] has now been generalized into
the type system. The previous behavior which often
occured of an expression "column + literal" forcing
the type of "literal" to be the same as that of "column"
will now usually not occur - the type of
"literal" is first derived from the Python type of the
literal, assuming standard native Python types + date
types, before falling back to that of the known type
on the other side of the expression. If the
"fallback" type is compatible (i.e. CHAR from String),
the literal side will use that. TypeDecorator
types override this by default to coerce the "literal"
side unconditionally, which can be changed by implementing
the coerce_compared_value() method. Also part of
[ticket:1683].
- Made sqlalchemy.sql.expressions.Executable part of public
API, used for any expression construct that can be sent to
execute(). FunctionElement now inherits Executable so that
it gains execution_options(), which are also propagated
to the select() that's generated within execute().
Executable in turn subclasses _Generative which marks
any ClauseElement that supports the @_generative
decorator - these may also become "public" for the benefit
of the compiler extension at some point.
- A change to the solution for [ticket:1579] - an end-user
defined bind parameter name that directly conflicts with
a column-named bind generated directly from the SET or
VALUES clause of an update/insert generates a compile error.
This reduces call counts and eliminates some cases where
undesirable name conflicts could still occur.
- Column() requires a type if it has no foreign keys (this is
not new). An error is now raised if a Column() has no type
and no foreign keys. [ticket:1705]
- the "scale" argument of the Numeric() type is honored when
coercing a returned floating point value into a string
on its way to Decimal - this allows accuracy to function
on SQLite, MySQL. [ticket:1717]
- the copy() method of Column now copies over uninitialized
"on table attach" events. Helps with the new declarative
"mixin" capability.
- engines
- Added an optional C extension to speed up the sql layer by
reimplementing RowProxy and the most common result processors.
The actual speedups will depend heavily on your DBAPI and
the mix of datatypes used in your tables, and can vary from
a 30% improvement to more than 200%. It also provides a modest
(~15-20%) indirect improvement to ORM speed for large queries.
Note that it is *not* built/installed by default.
See README for installation instructions.
- the execution sequence pulls all rowcount/last inserted ID
info from the cursor before commit() is called on the
DBAPI connection in an "autocommit" scenario. This helps
mxodbc with rowcount and is probably a good idea overall.
- Opened up logging a bit such that isEnabledFor() is called
more often, so that changes to the log level for engine/pool
will be reflected on next connect. This adds a small
amount of method call overhead. It's negligible and will make
life a lot easier for all those situations when logging
just happens to be configured after create_engine() is called.
[ticket:1719]
- The assert_unicode flag is deprecated. SQLAlchemy will raise
a warning in all cases where it is asked to encode a non-unicode
Python string, as well as when a Unicode or UnicodeType type
is explicitly passed a bytestring. The String type will do nothing
for DBAPIs that already accept Python unicode objects.
- Bind parameters are sent as a tuple instead of a list. Some
backend drivers will not accept bind parameters as a list.
- threadlocal engine wasn't properly closing the connection
upon close() - fixed that.
- Transaction object doesn't rollback or commit if it isn't
"active", allows more accurate nesting of begin/rollback/commit.
- Python unicode objects as binds result in the Unicode type,
not string, thus eliminating a certain class of unicode errors
on drivers that don't support unicode binds.
- Added "logging_name" argument to create_engine(), Pool() constructor
as well as "pool_logging_name" argument to create_engine() which
filters down to that of Pool. Issues the given string name
within the "name" field of logging messages instead of the default
hex identifier string. [ticket:1555]
- The visit_pool() method of Dialect is removed, and replaced with
on_connect(). This method returns a callable which receives
the raw DBAPI connection after each one is created. The callable
is assembled into a first_connect/connect pool listener by the
connection strategy if non-None. Provides a simpler interface
for dialects.
- StaticPool now initializes, disposes and recreates without
opening a new connection - the connection is only opened when
first requested. dispose() also works on AssertionPool now.
[ticket:1728]
- metadata
- Added the ability to strip schema information when using
"tometadata" by passing "schema=None" as an argument. If schema
is not specified then the table's schema is retained.
[ticket: 1673]
- declarative
- DeclarativeMeta exclusively uses cls.__dict__ (not dict_)
as the source of class information; _as_declarative exclusively
uses the dict_ passed to it as the source of class information
(which when using DeclarativeMeta is cls.__dict__). This should
in theory make it easier for custom metaclasses to modify
the state passed into _as_declarative.
- declarative now accepts mixin classes directly, as a means
to provide common functional and column-based elements on
all subclasses, as well as a means to propagate a fixed
set of __table_args__ or __mapper_args__ to subclasses.
For custom combinations of __table_args__/__mapper_args__ from
an inherited mixin to local, descriptors can now be used.
New details are all up in the Declarative documentation.
Thanks to Chris Withers for putting up with my strife
on this. [ticket:1707]
- the __mapper_args__ dict is copied when propagating to a subclass,
and is taken straight off the class __dict__ to avoid any
propagation from the parent. mapper inheritance already
propagates the things you want from the parent mapper.
[ticket:1393]
- An exception is raised when a single-table subclass specifies
a column that is already present on the base class.
[ticket:1732]
- mysql
- Fixed reflection bug whereby when COLLATE was present,
nullable flag and server defaults would not be reflected.
[ticket:1655]
- Fixed reflection of TINYINT(1) "boolean" columns defined with
integer flags like UNSIGNED.
- Further fixes for the mysql-connector dialect. [ticket:1668]
- Composite PK table on InnoDB where the "autoincrement" column
isn't first will emit an explicit "KEY" phrase within
CREATE TABLE thereby avoiding errors, [ticket:1496]
- Added reflection/create table support for a wide range
of MySQL keywords. [ticket:1634]
- Fixed import error which could occur reflecting tables on
a Windows host [ticket:1580]
- mssql
- Re-established support for the pymssql dialect.
- Various fixes for implicit returning, reflection,
etc. - the MS-SQL dialects aren't quite complete
in 0.6 yet (but are close)
- Added basic support for mxODBC [ticket:1710].
- Removed the text_as_varchar option.
- oracle
- "out" parameters require a type that is supported by
cx_oracle. An error will be raised if no cx_oracle
type can be found.
- Oracle 'DATE' now does not perform any result processing,
as the DATE type in Oracle stores full date+time objects,
that's what you'll get. Note that the generic types.Date
type *will* still call value.date() on incoming values,
however. When reflecting a table, the reflected type
will be 'DATE'.
- Added preliminary support for Oracle's WITH_UNICODE
mode. At the very least this establishes initial
support for cx_Oracle with Python 3. When WITH_UNICODE
mode is used in Python 2.xx, a large and scary warning
is emitted asking that the user seriously consider
the usage of this difficult mode of operation.
[ticket:1670]
- The except_() method now renders as MINUS on Oracle,
which is more or less equivalent on that platform.
[ticket:1712]
- Added support for rendering and reflecting
TIMESTAMP WITH TIME ZONE, i.e. TIMESTAMP(timezone=True).
[ticket:651]
- Oracle INTERVAL type can now be reflected.
- sqlite
- Added "native_datetime=True" flag to create_engine().
This will cause the DATE and TIMESTAMP types to skip
all bind parameter and result row processing, under
the assumption that PARSE_DECLTYPES has been enabled
on the connection. Note that this is not entirely
compatible with the "func.current_date()", which
will be returned as a string. [ticket:1685]
- sybase
- Implemented a preliminary working dialect for Sybase,
with sub-implementations for Python-Sybase as well
as Pyodbc. Handles table
creates/drops and basic round trip functionality.
Does not yet include reflection or comprehensive
support of unicode/special expressions/etc.
- examples
- Changed the beaker cache example a bit to have a separate
RelationCache option for lazyload caching. This object
does a lookup among any number of potential attributes
more efficiently by grouping several into a common structure.
Both FromCache and RelationCache are simpler individually.
- documentation
- Major cleanup work in the docs to link class, function, and
method names into the API docs. [ticket:1700/1702/1703]
0.6beta1
========
- Major Release
- For the full set of feature descriptions, see
http://www.sqlalchemy.org/trac/wiki/06Migration .
This document is a work in progress.
- All bug fixes and feature enhancements from the most
recent 0.5 version and below are also included within 0.6.
- Platforms targeted now include Python 2.4/2.5/2.6, Python
3.1, Jython2.5.
- orm
- Changes to query.update() and query.delete():
- the 'expire' option on query.update() has been renamed to
'fetch', thus matching that of query.delete().
'expire' is deprecated and issues a warning.
- query.update() and query.delete() both default to
'evaluate' for the synchronize strategy.
- the 'synchronize' strategy for update() and delete()
raises an error on failure. There is no implicit fallback
onto "fetch". Failure of evaluation is based on the
structure of criteria, so success/failure is deterministic
based on code structure.
- Enhancements on many-to-one relations:
- many-to-one relations now fire off a lazyload in fewer
cases, including in most cases will not fetch the "old"
value when a new one is replaced.
- many-to-one relation to a joined-table subclass now uses
get() for a simple load (known as the "use_get"
condition), i.e. Related->Sub(Base), without the need to
redefine the primaryjoin condition in terms of the base
table. [ticket:1186]
- specifying a foreign key with a declarative column, i.e.
ForeignKey(MyRelatedClass.id) doesn't break the "use_get"
condition from taking place [ticket:1492]
- relation(), eagerload(), and eagerload_all() now feature
an option called "innerjoin". Specify `True` or `False` to
control whether an eager join is constructed as an INNER
or OUTER join. Default is `False` as always. The mapper
options will override whichever setting is specified on
relation(). Should generally be set for many-to-one, not
nullable foreign key relations to allow improved join
performance. [ticket:1544]
- the behavior of eagerloading such that the main query is
wrapped in a subquery when LIMIT/OFFSET are present now
makes an exception for the case when all eager loads are
many-to-one joins. In those cases, the eager joins are
against the parent table directly along with the
limit/offset without the extra overhead of a subquery,
since a many-to-one join does not add rows to the result.
- Enhancements / Changes on Session.merge():
- the "dont_load=True" flag on Session.merge() is deprecated
and is now "load=False".
- Session.merge() is performance optimized, using half the
call counts for "load=False" mode compared to 0.5 and
significantly fewer SQL queries in the case of collections
for "load=True" mode.
- merge() will not issue a needless merge of attributes if the
given instance is the same instance which is already present.
- merge() now also merges the "options" associated with a given
state, i.e. those passed through query.options() which follow
along with an instance, such as options to eagerly- or
lazyily- load various attributes. This is essential for
the construction of highly integrated caching schemes. This
is a subtle behavioral change vs. 0.5.
- A bug was fixed regarding the serialization of the "loader
path" present on an instance's state, which is also necessary
when combining the usage of merge() with serialized state
and associated options that should be preserved.
- The all new merge() is showcased in a new comprehensive
example of how to integrate Beaker with SQLAlchemy. See
the notes in the "examples" note below.
- Primary key values can now be changed on a joined-table inheritance
object, and ON UPDATE CASCADE will be taken into account when
the flush happens. Set the new "passive_updates" flag to False
on mapper() when using SQLite or MySQL/MyISAM. [ticket:1362]
- flush() now detects when a primary key column was updated by
an ON UPDATE CASCADE operation from another primary key, and
can then locate the row for a subsequent UPDATE on the new PK
value. This occurs when a relation() is there to establish
the relationship as well as passive_updates=True. [ticket:1671]
- the "save-update" cascade will now cascade the pending *removed*
values from a scalar or collection attribute into the new session
during an add() operation. This so that the flush() operation
will also delete or modify rows of those disconnected items.
- Using a "dynamic" loader with a "secondary" table now produces
a query where the "secondary" table is *not* aliased. This
allows the secondary Table object to be used in the "order_by"
attribute of the relation(), and also allows it to be used
in filter criterion against the dynamic relation.
[ticket:1531]
- relation() with uselist=False will emit a warning when
an eager or lazy load locates more than one valid value for
the row. This may be due to primaryjoin/secondaryjoin
conditions which aren't appropriate for an eager LEFT OUTER
JOIN or for other conditions. [ticket:1643]
- an explicit check occurs when a synonym() is used with
map_column=True, when a ColumnProperty (deferred or otherwise)
exists separately in the properties dictionary sent to mapper
with the same keyname. Instead of silently replacing
the existing property (and possible options on that property),
an error is raised. [ticket:1633]
- a "dynamic" loader sets up its query criterion at construction
time so that the actual query is returned from non-cloning
accessors like "statement".
- the "named tuple" objects returned when iterating a
Query() are now pickleable.
- mapping to a select() construct now requires that you
make an alias() out of it distinctly. This to eliminate
confusion over such issues as [ticket:1542]
- query.join() has been reworked to provide more consistent
behavior and more flexibility (includes [ticket:1537])
- query.select_from() accepts multiple clauses to produce
multiple comma separated entries within the FROM clause.
Useful when selecting from multiple-homed join() clauses.
- query.select_from() also accepts mapped classes, aliased()
constructs, and mappers as arguments. In particular this
helps when querying from multiple joined-table classes to ensure
the full join gets rendered.
- query.get() can be used with a mapping to an outer join
where one or more of the primary key values are None.
[ticket:1135]
- query.from_self(), query.union(), others which do a
"SELECT * from (SELECT...)" type of nesting will do
a better job translating column expressions within the subquery
to the columns clause of the outer query. This is
potentially backwards incompatible with 0.5, in that this
may break queries with literal expressions that do not have labels
applied (i.e. literal('foo'), etc.)
[ticket:1568]
- relation primaryjoin and secondaryjoin now check that they
are column-expressions, not just clause elements. this prohibits
things like FROM expressions being placed there directly.
[ticket:1622]
- `expression.null()` is fully understood the same way
None is when comparing an object/collection-referencing
attribute within query.filter(), filter_by(), etc.
[ticket:1415]
- added "make_transient()" helper function which transforms a
persistent/ detached instance into a transient one (i.e.
deletes the instance_key and removes from any session.)
[ticket:1052]
- the allow_null_pks flag on mapper() is deprecated, and
the feature is turned "on" by default. This means that
a row which has a non-null value for any of its primary key
columns will be considered an identity. The need for this
scenario typically only occurs when mapping to an outer join.
[ticket:1339]
- the mechanics of "backref" have been fully merged into the
finer grained "back_populates" system, and take place entirely
within the _generate_backref() method of RelationProperty. This
makes the initialization procedure of RelationProperty
simpler and allows easier propagation of settings (such as from
subclasses of RelationProperty) into the reverse reference.
The internal BackRef() is gone and backref() returns a plain
tuple that is understood by RelationProperty.
- The version_id_col feature on mapper() will raise a warning when
used with dialects that don't support "rowcount" adequately.
[ticket:1569]
- added "execution_options()" to Query, to so options can be
passed to the resulting statement. Currently only
Select-statements have these options, and the only option
used is "stream_results", and the only dialect which knows
"stream_results" is psycopg2.
- Query.yield_per() will set the "stream_results" statement
option automatically.
- Deprecated or removed:
* 'allow_null_pks' flag on mapper() is deprecated. It does
nothing now and the setting is "on" in all cases.
* '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".
* ScopedSession.mapper remains deprecated. See the
usage recipe at
http://www.sqlalchemy.org/trac/wiki/UsageRecipes/SessionAwareMapper
* 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.
- sql
- the "autocommit" flag on select() and text() as well
as select().autocommit() are deprecated - now call
.execution_options(autocommit=True) on either of those
constructs, also available directly on Connection and orm.Query.
- the autoincrement flag on column now indicates the column
which should be linked to cursor.lastrowid, if that method
is used. See the API docs for details.
- an executemany() now requires that all bound parameter
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]
- returning() support is native to insert(), update(),
delete(). Implementations of varying levels of
functionality exist for Postgresql, Firebird, MSSQL and
Oracle. returning() can be called explicitly with column
expressions which are then returned in the resultset,
usually via fetchone() or first().
insert() constructs will also use RETURNING implicitly to
get newly generated primary key values, if the database
version in use supports it (a version number check is
performed). This occurs if no end-user returning() was
specified.
- union(), intersect(), except() and other "compound" types
of statements have more consistent behavior w.r.t.
parenthesizing. Each compound element embedded within
another will now be grouped with parenthesis - previously,
the first compound element in the list would not be grouped,
as SQLite doesn't like a statement to start with
parenthesis. However, Postgresql in particular has
precedence rules regarding INTERSECT, and it is
more consistent for parenthesis to be applied equally
to all sub-elements. So now, the workaround for SQLite
is also what the workaround for PG was previously -
when nesting compound elements, the first one usually needs
".alias().select()" called on it to wrap it inside
of a subquery. [ticket:1665]
- insert() and update() constructs can now embed bindparam()
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]
- the Binary type now returns data as a Python string
(or a "bytes" type in Python 3), instead of the built-
in "buffer" type. This allows symmetric round trips
of binary data. [ticket:1524]
- Added a tuple_() construct, allows sets of expressions
to be compared to another set, typically with IN against
composite primary keys or similar. Also accepts an
IN with multiple columns. The "scalar select can
have only one column" error message is removed - will
rely upon the database to report problems with
col mismatch.
- User-defined "default" and "onupdate" callables which
accept a context should now call upon
"context.current_parameters" to get at the dictionary
of bind parameters currently being processed. This
dict is available in the same way regardless of
single-execute or executemany-style statement execution.
- multi-part schema names, i.e. with dots such as
"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]
- removed needless "counter" behavior with select()
labelnames that match a column name in the table,
i.e. generates "tablename_id" for "id", instead of
"tablename_id_1" in an attempt to avoid naming
conflicts, when the table has a column actually
named "tablename_id" - this is because
the labeling logic is always applied to all columns
so a naming conflict will never occur.
- calling expr.in_([]), i.e. with an empty list, emits a warning
before issuing the usual "expr != expr" clause. The
"expr != expr" can be very expensive, and it's preferred
that the user not issue in_() if the list is empty,
instead simply not querying, or modifying the criterion
as appropriate for more complex situations.
[ticket:1628]
- Added "execution_options()" to select()/text(), which set the
default options for the Connection. See the note in "engines".
- Deprecated or removed:
* "scalar" flag on select() is removed, use
select.as_scalar().
* "shortname" attribute on bindparam() is removed.
* postgres_returning, firebird_returning flags on
insert(), update(), delete() are deprecated, use
the new returning() method.
* fold_equivalents flag on join is deprecated (will remain
until [ticket:1131] is implemented)
- engines
- transaction isolation level may be specified with
create_engine(... isolation_level="..."); available on
postgresql and sqlite. [ticket:443]
- Connection has execution_options(), generative method
which accepts keywords that affect how the statement
is executed w.r.t. the DBAPI. Currently supports
"stream_results", causes psycopg2 to use a server
side cursor for that statement, as well as
"autocommit", which is the new location for the "autocommit"
option from select() and text(). select() and
text() also have .execution_options() as well as
ORM Query().
- fixed the import for entrypoint-driven dialects to
not rely upon silly tb_info trick to determine import
error status. [ticket:1630]
- added first() method to ResultProxy, returns first row and
closes result set immediately.
- RowProxy objects are now pickleable, i.e. the object returned
by result.fetchone(), result.fetchall() etc.
- RowProxy no longer has a close() method, as the row no longer
maintains a reference to the parent. Call close() on
the parent ResultProxy instead, or use autoclose.
- ResultProxy internals have been overhauled to greatly reduce
method call counts when fetching columns. Can provide a large
speed improvement (up to more than 100%) when fetching large
result sets. The improvement is larger when fetching columns
that have no type-level processing applied and when using
results as tuples (instead of as dictionaries). Many
thanks to Elixir's Gaëtan de Menten for this dramatic
improvement ! [ticket:1586]
- Databases which rely upon postfetch of "last inserted id"
to get at a generated sequence value (i.e. MySQL, MS-SQL)
now work correctly when there is a composite primary key
where the "autoincrement" column is not the first primary
key column in the table.
- the last_inserted_ids() method has been renamed to the
descriptor "inserted_primary_key".
- setting echo=False on create_engine() now sets the loglevel
to WARN instead of NOTSET. This so that logging can be
disabled for a particular engine even if logging
for "sqlalchemy.engine" is enabled overall. Note that the
default setting of "echo" is `None`. [ticket:1554]
- ConnectionProxy now has wrapper methods for all transaction
lifecycle events, including begin(), rollback(), commit()
begin_nested(), begin_prepared(), prepare(), release_savepoint(),
etc.
- Connection pool logging now uses both INFO and DEBUG
log levels for logging. INFO is for major events such
as invalidated connections, DEBUG for all the acquire/return
logging. `echo_pool` can be False, None, True or "debug"
the same way as `echo` works.
- All pyodbc-dialects now support extra pyodbc-specific
kw arguments 'ansi', 'unicode_results', 'autocommit'.
[ticket:1621]
- the "threadlocal" engine has been rewritten and simplified
and now supports SAVEPOINT operations.
- deprecated or removed
* result.last_inserted_ids() is deprecated. Use
result.inserted_primary_key
* dialect.get_default_schema_name(connection) is now
public via dialect.default_schema_name.
* the "connection" argument from engine.transaction() and
engine.run_callable() is removed - Connection itself
now has those methods. All four methods accept
*args and **kwargs which are passed to the given callable,
as well as the operating connection.
- schema
- the `__contains__()` method of `MetaData` now accepts
strings or `Table` objects as arguments. If given
a `Table`, the argument is converted to `table.key` first,
i.e. "[schemaname.]<tablename>" [ticket:1541]
- deprecated MetaData.connect() and
ThreadLocalMetaData.connect() have been removed - send
the "bind" attribute to bind a metadata.
- deprecated metadata.table_iterator() method removed (use
sorted_tables)
- deprecated PassiveDefault - use DefaultClause.
- the "metadata" argument is removed from DefaultGenerator
and subclasses, but remains locally present on Sequence,
which is a standalone construct in DDL.
- Removed public mutability from Index and Constraint
objects:
- ForeignKeyConstraint.append_element()
- Index.append_column()
- UniqueConstraint.append_column()
- PrimaryKeyConstraint.add()
- PrimaryKeyConstraint.remove()
These should be constructed declaratively (i.e. in one
construction).
- The "start" and "increment" attributes on Sequence now
generate "START WITH" and "INCREMENT BY" by default,
on Oracle and Postgresql. Firebird doesn't support
these keywords right now. [ticket:1545]
- UniqueConstraint, Index, PrimaryKeyConstraint all accept
lists of column names or column objects as arguments.
- Other removed things:
- Table.key (no idea what this was for)
- Table.primary_key is not assignable - use
table.append_constraint(PrimaryKeyConstraint(...))
- Column.bind (get via column.table.bind)
- Column.metadata (get via column.table.metadata)
- Column.sequence (use column.default)
- ForeignKey(constraint=some_parent) (is now private _constraint)
- The use_alter flag on ForeignKey is now a shortcut option
for operations that can be hand-constructed using the
DDL() event system. A side effect of this refactor is
that ForeignKeyConstraint objects with use_alter=True
will *not* be emitted on SQLite, which does not support
ALTER for foreign keys.
- ForeignKey and ForeignKeyConstraint objects now correctly
copy() all their public keyword arguments. [ticket:1605]
- Reflection/Inspection
- Table reflection has been expanded and generalized into
a new API called "sqlalchemy.engine.reflection.Inspector".
The Inspector object provides fine-grained information about
a wide variety of schema information, with room for expansion,
including table names, column names, view definitions, sequences,
indexes, etc.
- Views are now reflectable as ordinary Table objects. The same
Table constructor is used, with the caveat that "effective"
primary and foreign key constraints aren't part of the reflection
results; these have to be specified explicitly if desired.
- The existing autoload=True system now uses Inspector underneath
so that each dialect need only return "raw" data about tables
and other objects - Inspector is the single place that information
is compiled into Table objects so that consistency is at a maximum.
- DDL
- the DDL system has been greatly expanded. the DDL() class
now extends the more generic DDLElement(), which forms the basis
of many new constructs:
- CreateTable()
- DropTable()
- AddConstraint()
- DropConstraint()
- CreateIndex()
- DropIndex()
- CreateSequence()
- DropSequence()
These support "on" and "execute-at()" just like plain DDL()
does. User-defined DDLElement subclasses can be created and
linked to a compiler using the sqlalchemy.ext.compiler extension.
- The signature of the "on" callable passed to DDL() and
DDLElement() is revised as follows:
"ddl" - the DDLElement object itself.
"event" - the string event name.
"target" - previously "schema_item", the Table or
MetaData object triggering the event.
"connection" - the Connection object in use for the operation.
**kw - keyword arguments. In the case of MetaData before/after
create/drop, the list of Table objects for which
CREATE/DROP DDL is to be issued is passed as the kw
argument "tables". This is necessary for metadata-level
DDL that is dependent on the presence of specific tables.
- the "schema_item" attribute of DDL has been renamed to
"target".
- dialect refactor
- Dialect modules are now broken into database dialects
plus DBAPI implementations. Connect URLs are now
preferred to be specified using dialect+driver://...,
i.e. "mysql+mysqldb://scott:tiger@localhost/test". See
the 0.6 documentation for examples.
- the setuptools entrypoint for external dialects is now
called "sqlalchemy.dialects".
- the "owner" keyword argument is removed from Table. Use
"schema" to represent any namespaces to be prepended to
the table name.
- server_version_info becomes a static attribute.
- dialects receive an initialize() event on initial
connection to determine connection properties.
- dialects receive a visit_pool event have an opportunity
to establish pool listeners.
- cached TypeEngine classes are cached per-dialect class
instead of per-dialect.
- new UserDefinedType should be used as a base class for
new types, which preserves the 0.5 behavior of
get_col_spec().
- The result_processor() method of all type classes now
accepts a second argument "coltype", which is the DBAPI
type argument from cursor.description. This argument
can help some types decide on the most efficient processing
of result values.
- Deprecated Dialect.get_params() removed.
- Dialect.get_rowcount() has been renamed to a descriptor
"rowcount", and calls cursor.rowcount directly. Dialects
which need to hardwire a rowcount in for certain calls
should override the method to provide different behavior.
- DefaultRunner and subclasses have been removed. The job
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]
- Functions and operators generated by the compiler now use
(almost) regular dispatch functions of the form
"visit_<opname>" and "visit_<funcname>_fn" to provide
customed processing. This replaces the need to copy the
"functions" and "operators" dictionaries in compiler
subclasses with straightforward visitor methods, and also
allows compiler subclasses complete control over
rendering, as the full _Function or _BinaryExpression
object is passed in.
- postgresql
- New dialects: pg8000, zxjdbc, and pypostgresql
on py3k.
- The "postgres" dialect is now named "postgresql" !
Connection strings look like:
postgresql://scott:tiger@localhost/test
postgresql+pg8000://scott:tiger@localhost/test
The "postgres" name remains for backwards compatiblity
in the following ways:
- There is a "postgres.py" dummy dialect which
allows old URLs to work, i.e.
postgres://scott:tiger@localhost/test
- The "postgres" name can be imported from the old
"databases" module, i.e. "from
sqlalchemy.databases import postgres" as well as
"dialects", "from sqlalchemy.dialects.postgres
import base as pg", will send a deprecation
warning.
- Special expression arguments are now named
"postgresql_returning" and "postgresql_where", but
the older "postgres_returning" and
"postgres_where" names still work with a
deprecation warning.
- "postgresql_where" now accepts SQL expressions which
can also include literals, which will be quoted as needed.
- The psycopg2 dialect now uses psycopg2's "unicode extension"
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.
- Added new ENUM type, which exists as a schema-level
construct and extends the generic Enum type. Automatically
associates itself with tables and their parent metadata
to issue the appropriate CREATE TYPE/DROP TYPE
commands as needed, supports unicode labels, supports
reflection. [ticket:1511]
- INTERVAL supports an optional "precision" argument
corresponding to the argument that PG accepts.
- using new dialect.initialize() feature to set up
version-dependent behavior.
- somewhat better support for % signs in table/column names;
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]
- Inserting NULL into a primary key + foreign key column
will allow the "not null constraint" error to raise,
not an attempt to execute a nonexistent "col_id_seq"
sequence. [ticket:1516]
- autoincrement SELECT statements, i.e. those which
select from a procedure that modifies rows, now work
with server-side cursor mode (the named cursor isn't
used for such statements.)
- postgresql dialect can properly detect pg "devel" version
strings, i.e. "8.5devel" [ticket:1636]
- The psycopg2 now respects the statement option
"stream_results". This option overrides the connection setting
"server_side_cursors". If true, server side cursors will be
used for the statement. If false, they will not be used, even
if "server_side_cursors" is true on the
connection. [ticket:1619]
- mysql
- New dialects: oursql, a new native dialect,
MySQL Connector/Python, a native Python port of MySQLdb,
and of course zxjdbc on Jython.
- VARCHAR/NVARCHAR will not render without a length, raises
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.
- all the _detect_XXX() functions now run once underneath
dialect.initialize()
- 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]
- 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.
- ENUM now subclasses the new generic Enum type, and also handles
unicode values implicitly, if the given labelnames are unicode
objects.
- a column of type TIMESTAMP now defaults to NULL if
"nullable=False" is not passed to Column(), and no default
is present. This is now consistent with all other types,
and in the case of TIMESTAMP explictly renders "NULL"
due to MySQL's "switching" of default nullability
for TIMESTAMP columns. [ticket:1539]
- oracle
- unit tests pass 100% with cx_oracle !
- support for cx_Oracle's "native unicode" mode which does
not require NLS_LANG to be set. Use the latest 5.0.2 or
later of cx_oracle.
- an NCLOB type is added to the base types.
- use_ansi=False won't leak into the FROM/WHERE clause of
a statement that's selecting from a subquery that also
uses JOIN/OUTERJOIN.
- added native INTERVAL type to the dialect. This supports
only the DAY TO SECOND interval type so far due to lack
of support in cx_oracle for YEAR TO MONTH. [ticket:1467]
- usage of the CHAR type results in cx_oracle's
FIXED_CHAR dbapi type being bound to statements.
- the Oracle dialect now features NUMBER which intends
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]
- func.char_length is a generic function for LENGTH
- ForeignKey() which includes onupdate=<value> will emit a
warning, not emit ON UPDATE CASCADE which is unsupported
by oracle
- the keys() method of RowProxy() now returns the result
column names *normalized* to be SQLAlchemy case
insensitive names. This means they will be lower case for
case insensitive names, whereas the DBAPI would normally
return them as UPPERCASE names. This allows row keys() to
be compatible with further SQLAlchemy operations.
- using new dialect.initialize() feature to set up
version-dependent behavior.
- using types.BigInteger with Oracle will generate
NUMBER(19) [ticket:1125]
- "case sensitivity" feature will detect an all-lowercase
case-sensitive column name during reflect and add
"quote=True" to the generated Column, so that proper
quoting is maintained.
- firebird
- the keys() method of RowProxy() now returns the result
column names *normalized* to be SQLAlchemy case
insensitive names. This means they will be lower case for
case insensitive names, whereas the DBAPI would normally
return them as UPPERCASE names. This allows row keys() to
be compatible with further SQLAlchemy operations.
- using new dialect.initialize() feature to set up
version-dependent behavior.
- "case sensitivity" feature will detect an all-lowercase
case-sensitive column name during reflect and add
"quote=True" to the generated Column, so that proper
quoting is maintained.
- mssql
- MSSQL + Pyodbc + FreeTDS now works for the most part,
with possible exceptions regarding binary data as well as
unicode schema identifiers.
- the "has_window_funcs" flag is removed. LIMIT/OFFSET
usage will use ROW NUMBER as always, and if on an older
version of SQL Server, the operation fails. The behavior
is exactly the same except the error is raised by SQL
server instead of the dialect, and no flag setting is
required to enable it.
- the "auto_identity_insert" flag is removed. This feature
always takes effect when an INSERT statement overrides a
column that is known to have a sequence on it. As with
"has_window_funcs", if the underlying driver doesn't
support this, then you can't do this operation in any
case, so there's no point in having a flag.
- using new dialect.initialize() feature to set up
version-dependent behavior.
- removed references to sequence which is no longer used.
implicit identities in mssql work the same as implicit
sequences on any other dialects. Explicit sequences are
enabled through the use of "default=Sequence()". See
the MSSQL dialect documentation for more information.
- sqlite
- DATE, TIME and DATETIME types can now take optional storage_format
and regexp argument. storage_format can be used to store those types
using a custom string format. regexp allows to use a custom regular
expression to match string values from the database.
- Time and DateTime types now use by a default a stricter regular
expression to match strings from the database. Use the regexp
argument if you are using data stored in a legacy format.
- __legacy_microseconds__ on SQLite Time and DateTime types is not
supported anymore. You should use the storage_format argument
instead.
- Date, Time and DateTime types are now stricter in what they accept as
bind parameters: Date type only accepts date objects (and datetime
ones, because they inherit from date), Time only accepts time
objects, and DateTime only accepts date and datetime objects.
- Table() supports a keyword argument "sqlite_autoincrement", which
applies the SQLite keyword "AUTOINCREMENT" to the single integer
primary key column when generating DDL. Will prevent generation of
a separate PRIMARY KEY constraint. [ticket:1016]
- new dialects
- postgresql+pg8000
- postgresql+pypostgresql (partial)
- postgresql+zxjdbc
- mysql+pyodbc
- mysql+zxjdbc
- types
- The construction of types within dialects has been totally
overhauled. Dialects now define publically available types
as UPPERCASE names exclusively, and internal implementation
types using underscore identifiers (i.e. are private).
The system by which types are expressed in SQL and DDL
has been moved to the compiler system. This has the
effect that there are much fewer type objects within
most dialects. A detailed document on this architecture
for dialect authors is in
lib/sqlalchemy/dialects/type_migration_guidelines.txt .
- Types no longer make any guesses as to default
parameters. In particular, Numeric, Float, NUMERIC,
FLOAT, DECIMAL don't generate any length or scale unless
specified.
- types.Binary is renamed to types.LargeBinary, it only
produces BLOB, BYTEA, or a similar "long binary" type.
New base BINARY and VARBINARY
types have been added to access these MySQL/MS-SQL specific
types in an agnostic way [ticket:1664].
- 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.
- Most types result processors have been checked for possible speed
improvements. Specifically, the following generic types have been
optimized, resulting in varying speed improvements:
Unicode, PickleType, Interval, TypeDecorator, Binary.
Also the following dbapi-specific implementations have been improved:
Time, Date and DateTime on Sqlite, ARRAY on Postgresql,
Time on MySQL, Numeric(as_decimal=False) on MySQL, oursql and
pypostgresql, DateTime on cx_oracle and LOB-based types on cx_oracle.
- Reflection of types now returns the exact UPPERCASE
type within types.py, or the UPPERCASE type within
the dialect itself if the type is not a standard SQL
type. This means reflection now returns more accurate
information about reflected types.
- Added a new Enum generic type. Enum is a schema-aware object
to support databases which require specific DDL in order to
use enum or equivalent; in the case of PG it handles the
details of `CREATE TYPE`, and on other databases without
native enum support will by generate VARCHAR + an inline CHECK
constraint to enforce the enum.
[ticket:1109] [ticket:1511]
- The Interval type includes a "native" flag which controls
if native INTERVAL types (postgresql + oracle) are selected
if available, or not. "day_precision" and "second_precision"
arguments are also added which propagate as appropriately
to these native types. Related to [ticket:1467].
- The Boolean type, when used on a backend that doesn't
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]
- PickleType now uses == for comparison of values when
mutable=True, unless the "comparator" argument with a
comparsion function is specified to the type. Objects
being pickled will be compared based on identity (which
defeats the purpose of mutable=True) if __eq__() is not
overridden or a comparison function is not provided.
- The default "precision" and "scale" arguments of Numeric
and Float have been removed and now default to None.
NUMERIC and FLOAT will be rendered with no numeric
arguments by default unless these values are provided.
- AbstractType.get_search_list() is removed - the games
that was used for are no longer necessary.
- Added a generic BigInteger type, compiles to
BIGINT or NUMBER(19). [ticket:1125]
-ext
- sqlsoup has been overhauled to explicitly support an 0.5 style
session, using autocommit=False, autoflush=True. Default
behavior of SQLSoup now requires the usual usage of commit()
and rollback(), which have been added to its interface. An
explcit Session or scoped_session can be passed to the
constructor, allowing these arguments to be overridden.
- sqlsoup db.<sometable>.update() and delete() now call
query(cls).update() and delete(), respectively.
- sqlsoup now has execute() and connection(), which call upon
the Session methods of those names, ensuring that the bind is
in terms of the SqlSoup object's bind.
- sqlsoup objects no longer have the 'query' attribute - it's
not needed for sqlsoup's usage paradigm and it gets in the
way of a column that is actually named 'query'.
- The signature of the proxy_factory callable passed to
association_proxy is now (lazy_collection, creator,
value_attr, association_proxy), adding a fourth argument
that is the parent AssociationProxy argument. Allows
serializability and subclassing of the built in collections.
[ticket:1259]
- association_proxy now has basic comparator methods .any(),
.has(), .contains(), ==, !=, thanks to Scott Torborg.
[ticket:1372]
- examples
- The "query_cache" examples have been removed, and are replaced
with a fully comprehensive approach that combines the usage of
Beaker with SQLAlchemy. New query options are used to indicate
the caching characteristics of a particular Query, which
can also be invoked deep within an object graph when lazily
loading related objects. See /examples/beaker_caching/README.
0.5.9
=====
- sql
- Fixed erroneous self_group() call in expression package.
[ticket:1661]
0.5.8
=====
- sql
- The copy() method on Column now supports uninitialized,
unnamed Column objects. This allows easy creation of
declarative helpers which place common columns on multiple
subclasses.
- Default generators like Sequence() translate correctly
across a copy() operation.
- Sequence() and other DefaultGenerator objects are accepted
as the value for the "default" and "onupdate" keyword
arguments of Column, in addition to being accepted
positionally.
- Fixed a column arithmetic bug that affected column
correspondence for cloned selectables which contain
free-standing column expressions. This bug is
generally only noticeable when exercising newer
ORM behavior only availble in 0.6 via [ticket:1568],
but is more correct at the SQL expression level
as well. [ticket:1617]
- postgresql
- The extract() function, which was slightly improved in
0.5.7, needed a lot more work to generate the correct
typecast (the typecasts appear to be necessary in PG's
EXTRACT quite a lot of the time). The typecast is
now generated using a rule dictionary based
on PG's documentation for date/time/interval arithmetic.
It also accepts text() constructs again, which was broken
in 0.5.7. [ticket:1647]
- firebird
- Recognize more errors as disconnections. [ticket:1646]
0.5.7
=====
- orm
- contains_eager() now works with the automatically
generated subquery that results when you say
"query(Parent).join(Parent.somejoinedsubclass)", i.e.
when Parent joins to a joined-table-inheritance subclass.
Previously contains_eager() would erroneously add the
subclass table to the query separately producing a
cartesian product. An example is in the ticket
description. [ticket:1543]
- query.options() now only propagate to loaded objects
for potential further sub-loads only for options where
such behavior is relevant, keeping
various unserializable options like those generated
by contains_eager() out of individual instance states.
[ticket:1553]
- Session.execute() now locates table- and
mapper-specific binds based on a passed
in expression which is an insert()/update()/delete()
construct. [ticket:1054]
- Session.merge() now properly overwrites a many-to-one or
uselist=False attribute to None if the attribute
is also None in the given object to be merged.
- Fixed a needless select which would occur when merging
transient objects that contained a null primary key
identifier. [ticket:1618]
- Mutable collection passed to the "extension" attribute
of relation(), column_property() etc. will not be mutated
or shared among multiple instrumentation calls, preventing
duplicate extensions, such as backref populators,
from being inserted into the list.
[ticket:1585]
- Fixed the call to get_committed_value() on CompositeProperty.
[ticket:1504]
- Fixed bug where Query would crash if a join() with no clear
"left" side were called when a non-mapped column entity
appeared in the columns list. [ticket:1602]
- Fixed bug whereby composite columns wouldn't load properly
when configured on a joined-table subclass, introduced in
version 0.5.6 as a result of the fix for [ticket:1480].
[ticket:1616] thx to Scott Torborg.
- The "use get" behavior of many-to-one relations, i.e. that a
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]
- Fixed bug in query.update() when passing Cls.attribute
as keys in the value dict and using synchronize_session='expire'
('fetch' in 0.6). [ticket:1436]
- sql
- Fixed bug in two-phase transaction whereby commit() method
didn't set the full state which allows subsequent close()
call to succeed. [ticket:1603]
- Fixed the "numeric" paramstyle, which apparently is the
default paramstyle used by Informixdb.
- Repeat expressions in the columns clause of a select
are deduped based on the identity of each clause element,
not the actual string. This allows positional
elements to render correctly even if they all render
identically, such as "qmark" style bind parameters.
[ticket:1574]
- The cursor associated with connection pool connections
(i.e. _CursorFairy) now proxies `__iter__()` to the
underlying cursor correctly. [ticket:1632]
- 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].
- Fixed bug preventing alias() of an alias() from being
cloned or adapted (occurs frequently in ORM operations).
[ticket:1641]
- sqlite
- sqlite dialect properly generates CREATE INDEX for a table
that is in an alternate schema. [ticket:1439]
- postgresql
- Added support for reflecting the DOUBLE PRECISION type,
via a new postgres.PGDoublePrecision object.
This is postgresql.DOUBLE_PRECISION in 0.6.
[ticket:1085]
- Added support for reflecting the INTERVAL YEAR TO MONTH
and INTERVAL DAY TO SECOND syntaxes of the INTERVAL
type. [ticket:460]
- Corrected the "has_sequence" query to take current schema,
or explicit sequence-stated schema, into account.
[ticket:1576]
- Fixed the behavior of extract() to apply operator
precedence rules to the "::" operator when applying
the "timestamp" cast - ensures proper parenthesization.
[ticket:1611]
- mssql
- Changed the name of TrustedConnection to
Trusted_Connection when constructing pyodbc connect
arguments [ticket:1561]
- oracle
- The "table_names" dialect function, used by MetaData
.reflect(), omits "index overflow tables", a system
table generated by Oracle when "index only tables"
with overflow are used. These tables aren't accessible
via SQL and can't be reflected. [ticket:1637]
- ext
- A column can be added to a joined-table declarative
superclass after the class has been constructed
(i.e. via class-level attribute assignment), and
the column will be propagated down to
subclasses. [ticket:1570] This is the reverse
situation as that of [ticket:1523], fixed in 0.5.6.
- Fixed a slight inaccuracy in the sharding example.
Comparing equivalence of columns in the ORM is best
accomplished using col1.shares_lineage(col2).
[ticket:1491]
- Removed unused `load()` method from ShardedQuery.
[ticket:1606]
0.5.6
=====
- orm
- Fixed bug whereby inheritance discriminator part of a
composite primary key would fail on updates.
Continuation of [ticket:1300].
- Fixed bug which disallowed one side of a many-to-many
bidirectional reference to declare itself as "viewonly"
[ticket:1507]
- Added an assertion that prevents a @validates function
or other AttributeExtension from loading an unloaded
collection such that internal state may be corrupted.
[ticket:1526]
- Fixed bug which prevented two entities from mutually
replacing each other's primary key values within a single
flush() for some orderings of operations. [ticket:1519]
- Fixed an obscure issue whereby a joined-table subclass
with a self-referential eager load on the base class
would populate the related object's "subclass" table with
data from the "subclass" table of the parent.
[ticket:1485]
- relations() now have greater ability to be "overridden",
meaning a subclass that explicitly specifies a relation()
overriding that of the parent class will be honored
during a flush. This is currently to support
many-to-many relations from concrete inheritance setups.
Outside of that use case, YMMV. [ticket:1477]
- Squeezed a few more unnecessary "lazy loads" out of
relation(). When a collection is mutated, many-to-one
backrefs on the other side will not fire off to load
the "old" value, unless "single_parent=True" is set.
A direct assignment of a many-to-one still loads
the "old" value in order to update backref collections
on that value, which may be present in the session
already, thus maintaining the 0.5 behavioral contract.
[ticket:1483]
- Fixed bug whereby a load/refresh of joined table
inheritance attributes which were based on
column_property() or similar would fail to evaluate.
[ticket:1480]
- Improved support for MapperProperty objects overriding
that of an inherited mapper for non-concrete
inheritance setups - attribute extensions won't randomly
collide with each other. [ticket:1488]
- UPDATE and DELETE do not support ORDER BY, LIMIT, OFFSET,
etc. in standard SQL. Query.update() and Query.delete()
now raise an exception if any of limit(), offset(),
order_by(), group_by(), or distinct() have been
called. [ticket:1487]
- Added AttributeExtension to sqlalchemy.orm.__all__
- Improved error message when query() is called with
a non-SQL /entity expression. [ticket:1476]
- Using False or 0 as a polymorphic discriminator now
works on the base class as well as a subclass.
[ticket:1440]
- Added enable_assertions(False) to Query which disables
the usual assertions for expected state - used
by Query subclasses to engineer custom state.
[ticket:1424]. See
http://www.sqlalchemy.org/trac/wiki/UsageRecipes/PreFilteredQuery
for an example.
- Fixed recursion issue which occured if a mapped object's
`__len__()` or `__nonzero__()` method resulted in state
changes. [ticket:1501]
- Fixed incorrect exception raise in
Weak/StrongIdentityMap.add()
[ticket:1506]
- Fixed the error message for "could not find a FROM clause"
in query.join() which would fail to issue correctly
if the query was against a pure SQL construct.
[ticket:1522]
- Fixed a somewhat hypothetical issue which would result
in the wrong primary key being calculated for a mapper
using the old polymorphic_union function - but this
is old stuff. [ticket:1486]
- sql
- Fixed column.copy() to copy defaults and onupdates.
[ticket:1373]
- Fixed a bug in extract() introduced in 0.5.4 whereby
the string "field" argument was getting treated as a
ClauseElement, causing various errors within more
complex SQL transformations.
- Unary expressions such as DISTINCT propagate their
type handling to result sets, allowing conversions like
unicode and such to take place. [ticket:1420]
- Fixed bug in Table and Column whereby passing empty
dict for "info" argument would raise an exception.
[ticket:1482]
- oracle
- Backported 0.6 fix for Oracle alias names not getting
truncated. [ticket:1309]
- ext
- The collection proxies produced by associationproxy are now
pickleable. A user-defined proxy_factory however
is still not pickleable unless it defines __getstate__
and __setstate__. [ticket:1446]
- Declarative will raise an informative exception if
__table_args__ is passed as a tuple with no dict argument.
Improved documentation. [ticket:1468]
- Table objects declared in the MetaData can now be used
in string expressions sent to primaryjoin/secondaryjoin/
secondary - the name is pulled from the MetaData of the
declarative base. [ticket:1527]
- A column can be added to a joined-table subclass after
the class has been constructed (i.e. via class-level
attribute assignment). The column is added to the underlying
Table as always, but now the mapper will rebuild its
"join" to include the new column, instead of raising
an error about "no such column, use column_property()
instead". [ticket:1523]
- test
- Added examples into the test suite so they get exercised
regularly and cleaned up a couple deprecation warnings.
0.5.5
=======
- general
- unit tests have been migrated from unittest to nose. See
README.unittests for information on how to run the tests.
[ticket:970]
- orm
- The "foreign_keys" argument of relation() will now propagate
automatically to the backref in the same way that primaryjoin
and secondaryjoin do. For the extremely rare use case where
the backref of a relation() has intentionally different
"foreign_keys" configured, both sides now need to be
configured explicity (if they do in fact require this setting,
see the next note...).
- ...the only known (and really, really rare) use case where a
different foreign_keys setting was used on the
forwards/backwards side, a composite foreign key that
partially points to its own columns, has been enhanced such
that the fk->itself aspect of the relation won't be used to
determine relation direction.
- Session.mapper is now *deprecated*.
Call session.add() if you'd like a free-standing object to be
part of your session. Otherwise, a DIY version of
Session.mapper is now documented at
http://www.sqlalchemy.org/trac/wiki/UsageRecipes/SessionAwareMapper
The method will remain deprecated throughout 0.6.
- Fixed Query being able to join() from individual columns of a
joined-table subclass entity, i.e. query(SubClass.foo,
SubcClass.bar).join(<anything>). In most cases, an error
"Could not find a FROM clause to join from" would be
raised. In a few others, the result would be returned in terms
of the base class rather than the subclass - so applications
which relied on this erroneous result need to be
adjusted. [ticket:1431]
- Fixed a bug involving contains_eager(), which would apply
itself to a secondary (i.e. lazy) load in a particular rare
case, producing cartesian products. improved the targeting of
query.options() on secondary loads overall [ticket:1461].
- Fixed bug introduced in 0.5.4 whereby Composite types fail
when default-holding columns are flushed.
- Fixed another 0.5.4 bug whereby mutable attributes
(i.e. PickleType) wouldn't be deserialized correctly when the
whole object was serialized. [ticket:1426]
- Fixed bug whereby session.is_modified() would raise an
exception if any synonyms were in use.
- Fixed potential memory leak whereby previously pickled objects
placed back in a session would not be fully garbage collected
unless the Session were explicitly closed out.
- Fixed bug whereby list-based attributes, like pickletype and
PGArray, failed to be merged() properly.
- Repaired non-working attributes.set_committed_value function.
- Trimmed the pickle format for InstanceState which should
further reduce the memory footprint of pickled instances. The
format should be backwards compatible with that of 0.5.4 and
previous.
- sqlalchemy.orm.join and sqlalchemy.orm.outerjoin are now
added to __all__ in sqlalchemy.orm.*. [ticket:1463]
- Fixed bug where Query exception raise would fail when
a too-short composite primary key value were passed to
get(). [ticket:1458]
- sql
- 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.
- engine/pool
- Implemented recreate() for StaticPool.
0.5.4p2
=======
- sql
- Repaired the printing of SQL exceptions which are not
based on parameters or are not executemany() style.
- postgresql
- Deprecated the hardcoded TIMESTAMP function, which when
used as func.TIMESTAMP(value) would render "TIMESTAMP value".
This breaks on some platforms as PostgreSQL doesn't allow
bind parameters to be used in this context. The hard-coded
uppercase is also inappropriate and there's lots of other
PG casts that we'd need to support. So instead, use
text constructs i.e. select(["timestamp '12/05/09'"]).
0.5.4p1
=======
- orm
- Fixed an attribute error introduced in 0.5.4 which would
occur when merge() was used with an incomplete object.
0.5.4
=====
- orm
- Significant performance enhancements regarding Sessions/flush()
in conjunction with large mapper graphs, large numbers of
objects:
- Removed all* O(N) scanning behavior from the flush() process,
i.e. operations that were scanning the full session,
including an extremely expensive one that was erroneously
assuming primary key values were changing when this
was not the case.
* one edge case remains which may invoke a full scan,
if an existing primary key attribute is modified
to a new value.
- The Session's "weak referencing" behavior is now *full* -
no strong references whatsoever are made to a mapped object
or related items/collections in its __dict__. Backrefs and
other cycles in objects no longer affect the Session's ability
to lose all references to unmodified objects. Objects with
pending changes still are maintained strongly until flush.
[ticket:1398]
The implementation also improves performance by moving
the "resurrection" process of garbage collected items
to only be relevant for mappings that map "mutable"
attributes (i.e. PickleType, composite attrs). This removes
overhead from the gc process and simplifies internal
behavior.
If a "mutable" attribute change is the sole change on an object
which is then dereferenced, the mapper will not have access to
other attribute state when the UPDATE is issued. This may present
itself differently to some MapperExtensions.
The change also affects the internal attribute API, but not
the AttributeExtension interface nor any of the publically
documented attribute functions.
- The unit of work no longer genererates a graph of "dependency"
processors for the full graph of mappers during flush(), instead
creating such processors only for those mappers which represent
objects with pending changes. This saves a tremendous number
of method calls in the context of a large interconnected
graph of mappers.
- Cached a wasteful "table sort" operation that previously
occured multiple times per flush, also removing significant
method call count from flush().
- Other redundant behaviors have been simplified in
mapper._save_obj().
- Modified query_cls on DynamicAttributeImpl to accept a full
mixin version of the AppenderQuery, which allows subclassing
the AppenderMixin.
- The "polymorphic discriminator" column may be part of a
primary key, and it will be populated with the correct
discriminator value. [ticket:1300]
- Fixed the evaluator not being able to evaluate IS NULL clauses.
- Fixed the "set collection" function on "dynamic" relations to
initiate events correctly. Previously a collection could only
be assigned to a pending parent instance, otherwise modified
events would not be fired correctly. Set collection is now
compatible with merge(), fixes [ticket:1352].
- Allowed pickling of PropertyOption objects constructed with
instrumented descriptors; previously, pickle errors would occur
when pickling an object which was loaded with a descriptor-based
option, such as query.options(eagerload(MyClass.foo)).
- Lazy loader will not use get() if the "lazy load" 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]
- MapperOptions and other state associated with query.options()
is no longer bundled within callables associated with each
lazy/deferred-loading attribute during a load.
The options are now associated with the instance's
state object just once when it's populated. This removes
the need in most cases for per-instance/attribute loader
objects, improving load speed and memory overhead for
individual instances. [ticket:1391]
- Fixed another location where autoflush was interfering
with session.merge(). autoflush is disabled completely
for the duration of merge() now. [ticket:1360]
- Fixed bug which prevented "mutable primary key" dependency
logic from functioning properly on a one-to-one
relation(). [ticket:1406]
- Fixed bug in relation(), introduced in 0.5.3,
whereby a self referential relation
from a base class to a joined-table subclass would
not configure correctly.
- Fixed obscure mapper compilation issue when inheriting
mappers are used which would result in un-initialized
attributes.
- Fixed documentation for session weak_identity_map -
the default value is True, indicating a weak
referencing map in use.
- Fixed a unit of work issue whereby the foreign
key attribute on an item contained within a collection
owned by an object being deleted would not be set to
None if the relation() was self-referential. [ticket:1376]
- Fixed Query.update() and Query.delete() failures with eagerloaded
relations. [ticket:1378]
- It is now an error to specify both columns of a binary primaryjoin
condition in the foreign_keys or remote_side collection. Whereas
previously it was just nonsensical, but would succeed in a
non-deterministic way.
- schema
- Added a quote_schema() method to the IdentifierPreparer class
so that dialects can override how schemas get handled. This
enables the MSSQL dialect to treat schemas as multipart
identifiers, such as 'database.owner'. [ticket: 594, 1341]
- sql
- Back-ported the "compiler" extension from SQLA 0.6. This
is a standardized interface which allows the creation of custom
ClauseElement subclasses and compilers. In particular it's
handy as an alternative to text() when you'd like to
build a construct that has database-specific compilations.
See the extension docs for details.
- Exception messages are truncated when the list of bound
parameters is larger than 10, preventing enormous
multi-page exceptions from filling up screens and logfiles
for large executemany() statements. [ticket:1413]
- ``sqlalchemy.extract()`` is now dialect sensitive and can
extract components of timestamps idiomatically across the
supported databases, including SQLite.
- Fixed __repr__() and other _get_colspec() methods on
ForeignKey constructed from __clause_element__() style
construct (i.e. declarative columns). [ticket:1353]
- mysql
- Reflecting a FOREIGN KEY construct will take into account
a dotted schema.tablename combination, if the foreign key
references a table in a remote schema. [ticket:1405]
- mssql
- Modified how savepoint logic works to prevent it from
stepping on non-savepoint oriented routines. Savepoint
support is still very experimental.
- Added in reserved words for MSSQL that covers version 2008
and all prior versions. [ticket:1310]
- Corrected problem with information schema not working with a
binary collation based database. Cleaned up information schema
since it is only used by mssql now. [ticket:1343]
- sqlite
- Corrected the SLBoolean type so that it properly treats only 1
as True. [ticket:1402]
- Corrected the float type so that it correctly maps to a
SLFloat type when being reflected. [ticket:1273]
- extensions
- Fixed adding of deferred or other column properties to a
declarative class. [ticket:1379]
0.5.3
=====
- orm
- The "objects" argument to session.flush() is deprecated.
State which represents the linkage between a parent and
child object does not support "flushed" status on
one side of the link and not the other, so supporting
this operation leads to misleading results.
[ticket:1315]
- Query now implements __clause_element__() which produces
its selectable, which means a Query instance can be accepted
in many SQL expressions, including col.in_(query),
union(query1, query2), select([foo]).select_from(query),
etc.
- Query.join() can now construct multiple FROM clauses, if
needed. Such as, query(A, B).join(A.x).join(B.y)
might say SELECT A.*, B.* FROM A JOIN X, B JOIN Y.
Eager loading can also tack its joins onto those
multiple FROM clauses. [ticket:1337]
- Fixed bug in dynamic_loader() where append/remove events
after construction time were not being propagated to the
UOW to pick up on flush(). [ticket:1347]
- Fixed bug where column_prefix wasn't being checked before
not mapping an attribute that already had class-level
name present.
- a session.expire() on a particular collection attribute
will clear any pending backref additions as well, so that
the next access correctly returns only what was present
in the database. Presents some degree of a workaround for
[ticket:1315], although we are considering removing the
flush([objects]) feature altogether.
- Session.scalar() now converts raw SQL strings to text()
the same way Session.execute() does and accepts same
alternative **kw args.
- improvements to the "determine direction" logic of
relation() such that the direction of tricky situations
like mapper(A.join(B)) -> relation-> mapper(B) can be
determined.
- When flushing partial sets of objects using session.flush([somelist]),
pending objects which remain pending after the operation won't
inadvertently be added as persistent. [ticket:1306]
- Added "post_configure_attribute" method to InstrumentationManager,
so that the "listen_for_events.py" example works again.
[ticket:1314]
- a forward and complementing backwards reference which are both
of the same direction, i.e. ONETOMANY or MANYTOONE,
is now detected, and an error message is raised.
Saves crazy CircularDependencyErrors later on.
- Fixed bugs in Query regarding simultaneous selection of
multiple joined-table inheritance entities with common base
classes:
- previously the adaption applied to "B" on
"A JOIN B" would be erroneously partially applied
to "A".
- comparisons on relations (i.e. A.related==someb)
were not getting adapted when they should.
- Other filterings, like
query(A).join(A.bs).filter(B.foo=='bar'), were erroneously
adapting "B.foo" as though it were an "A".
- Fixed adaptation of EXISTS clauses via any(), has(), etc.
in conjunction with an aliased object on the left and
of_type() on the right. [ticket:1325]
- Added an attribute helper method ``set_committed_value`` in
sqlalchemy.orm.attributes. Given an object, attribute name,
and value, will set the value on the object as part of its
"committed" state, i.e. state that is understood to have
been loaded from the database. Helps with the creation of
homegrown collection loaders and such.
- Query won't fail with weakref error when a non-mapper/class
instrumented descriptor is passed, raises
"Invalid column expession".
- Query.group_by() properly takes into account aliasing applied
to the FROM clause, such as with select_from(), using
with_polymorphic(), or using from_self().
- sql
- An alias() of a select() will convert to a "scalar subquery"
when used in an unambiguously scalar context, i.e. it's used
in a comparison operation. This applies to
the ORM when using query.subquery() as well.
- Fixed missing _label attribute on Function object, others
when used in a select() with use_labels (such as when used
in an ORM column_property()). [ticket:1302]
- anonymous alias names now truncate down to the max length
allowed by the dialect. More significant on DBs like
Oracle with very small character limits. [ticket:1309]
- the __selectable__() interface has been replaced entirely
by __clause_element__().
- The per-dialect cache used by TypeEngine to cache
dialect-specific types is now a WeakKeyDictionary.
This to prevent dialect objects from
being referenced forever for an application that
creates an arbitrarily large number of engines
or dialects. There is a small performance penalty
which will be resolved in 0.6. [ticket:1299]
- sqlite
- Fixed SQLite reflection methods so that non-present
cursor.description, which triggers an auto-cursor
close, will be detected so that no results doesn't
fail on recent versions of pysqlite which raise
an error when fetchone() called with no rows present.
- postgresql
- Index reflection won't fail when an index with
multiple expressions is encountered.
- Added PGUuid and PGBit types to
sqlalchemy.databases.postgres. [ticket:1327]
- Refection of unknown PG types won't crash when those
types are specified within a domain. [ticket:1327]
- mssql
- Preliminary support for pymssql 1.0.1
- Corrected issue on mssql where max_identifier_length was
not being respected.
- extensions
- Fixed a recursive pickling issue in serializer, triggered
by an EXISTS or other embedded FROM construct.
- Declarative locates the "inherits" class using a search
through __bases__, to skip over mixins that are local
to subclasses.
- Declarative figures out joined-table inheritance primary join
condition even if "inherits" mapper argument is given
explicitly.
- Declarative will properly interpret the "foreign_keys" argument
on a backref() if it's a string.
- Declarative will accept a table-bound column as a property
when used in conjunction with __table__, if the column is already
present in __table__. The column will be remapped to the given
key the same way as when added to the mapper() properties dict.
0.5.2
======
- orm
- Further refined 0.5.1's warning about delete-orphan cascade
placed on a many-to-many relation. First, the bad news:
the warning will apply to both many-to-many as well as
many-to-one relations. This is necessary since in both
cases, SQLA does not scan the full set of potential parents
when determining "orphan" status - for a persistent object
it only detects an in-python de-association event to establish
the object as an "orphan". Next, the good news: to support
one-to-one via a foreign key or assocation table, or to
support one-to-many via an association table, a new flag
single_parent=True may be set which indicates objects
linked to the relation are only meant to have a single parent.
The relation will raise an error if multiple parent-association
events occur within Python.
- Adjusted the attribute instrumentation change from 0.5.1 to
fully establish instrumentation for subclasses where the mapper
was created after the superclass had already been fully
instrumented. [ticket:1292]
- Fixed bug in delete-orphan cascade whereby two one-to-one
relations from two different parent classes to the same target
class would prematurely expunge the instance.
- Fixed an eager loading bug whereby self-referential eager
loading would prevent other eager loads, self referential or not,
from joining to the parent JOIN properly. Thanks to Alex K
for creating a great test case.
- session.expire() and related methods will not expire() unloaded
deferred attributes. This prevents them from being needlessly
loaded when the instance is refreshed.
- query.join()/outerjoin() will now properly join an aliased()
construct to the existing left side, even if query.from_self()
or query.select_from(someselectable) has been called.
[ticket:1293]
- sql
- Further fixes to the "percent signs and spaces in column/table
names" functionality. [ticket:1284]
- mssql
- Restored convert_unicode handling. Results were being passed
on through without conversion. [ticket:1291]
- Really fixing the decimal handling this time. [ticket:1282].
- Modified table reflection code to use only kwargs when
constructing tables. [Ticket:1289]
0.5.1
========
- orm
- Removed an internal join cache which could potentially leak
memory when issuing query.join() repeatedly to ad-hoc
selectables.
- The "clear()", "save()", "update()", "save_or_update()"
Session methods have been deprecated, replaced by
"expunge_all()" and "add()". "expunge_all()" has also
been added to ScopedSession.
- Modernized the "no mapped table" exception and added a more
explicit __table__/__tablename__ exception to declarative.
- Concrete inheriting mappers now instrument attributes which
are inherited from the superclass, but are not defined for
the concrete mapper itself, with an InstrumentedAttribute that
issues a descriptive error when accessed. [ticket:1237]
- Added a new `relation()` keyword `back_populates`. This
allows configuation of backreferences using explicit
relations. [ticket:781] This is required when creating
bidirectional relations between a hierarchy of concrete
mappers and another class. [ticket:1237]
- Test coverage added for `relation()` objects specified on
concrete mappers. [ticket:1237]
- Query.from_self() as well as query.subquery() both disable
the rendering of eager joins inside the subquery produced.
The "disable all eager joins" feature is available publically
via a new query.enable_eagerloads() generative. [ticket:1276]
- Added a rudimental series of set operations to Query that
receive Query objects as arguments, including union(),
union_all(), intersect(), except_(), insertsect_all(),
except_all(). See the API documentation for
Query.union() for examples.
- Fixed bug that prevented Query.join() and eagerloads from
attaching to a query that selected from a union or aliased union.
- A short documentation example added for bidirectional
relations specified on concrete mappers. [ticket:1237]
- Mappers now instrument class attributes upon construction
with the final InstrumentedAttribute object which remains
persistent. The `_CompileOnAttr`/`__getattribute__()`
methodology has been removed. The net effect is that
Column-based mapped class attributes can now be used fully
at the class level without invoking a mapper compilation
operation, greatly simplifying typical usage patterns
within declarative. [ticket:1269]
- ColumnProperty (and front-end helpers such as ``deferred``) no
longer ignores unknown **keyword arguments.
- Fixed a bug with the unitofwork's "row switch" mechanism,
i.e. the conversion of INSERT/DELETE into an UPDATE, when
combined with joined-table inheritance and an object
which contained no defined values for the child table where
an UPDATE with no SET clause would be rendered.
- Using delete-orphan on a many-to-many relation is deprecated.
This produces misleading or erroneous results since SQLA does
not retrieve the full list of "parents" for m2m. To get delete-orphan
behavior with an m2m table, use an explcit association class
so that the individual association row is treated as a parent.
[ticket:1281]
- delete-orphan cascade always requires delete cascade. Specifying
delete-orphan without delete now raises a deprecation warning.
[ticket:1281]
- sql
- Improved the methodology to handling percent signs in column
names from [ticket:1256]. Added more tests. MySQL and
PostgreSQL dialects still do not issue correct CREATE TABLE
statements for identifiers with percent signs in them.
- schema
- Index now accepts column-oriented InstrumentedAttributes
(i.e. column-based mapped class attributes) as column
arguments. [ticket:1214]
- Column with no name (as in declarative) won't raise a
NoneType error when it's string output is requsted
(such as in a stack trace).
- Fixed bug when overriding a Column with a ForeignKey
on a reflected table, where derived columns (i.e. the
"virtual" columns of a select, etc.) would inadvertently
call upon schema-level cleanup logic intended only
for the original column. [ticket:1278]
- declarative
- Can now specify Column objects on subclasses which have no
table of their own (i.e. use single table inheritance).
The columns will be appended to the base table, but only
mapped by the subclass.
- For both joined and single inheriting subclasses, the subclass
will only map those columns which are already mapped on the
superclass and those explicit on the subclass. Other
columns that are present on the `Table` will be excluded
from the mapping by default, which can be disabled
by passing a blank `exclude_properties` collection to the
`__mapper_args__`. This is so that single-inheriting
classes which define their own columns are the only classes
to map those columns. The effect is actually a more organized
mapping than you'd normally get with explicit `mapper()`
calls unless you set up the `exclude_properties` arguments
explicitly.
- It's an error to add new Column objects to a declarative class
that specified an existing table using __table__.
- mysql
- Added the missing keywords from MySQL 4.1 so they get escaped
properly.
- mssql
- Corrected handling of large decimal values with more robust
tests. Removed string manipulation on floats. [ticket:1280]
- Modified the do_begin handling in mssql to use the Cursor not
the Connection so it is DBAPI compatible.
- Corrected SAVEPOINT support on adodbapi by changing the
handling of savepoint_release, which is unsupported on mssql.
0.5.0
========
- new features
- general
- Documentation has been converted to Sphinx. In particular,
the generated API documentation has been constructed into a
full blown "API Reference" section which organizes editorial
documentation combined with generated docstrings. Cross
linking between sections and API docs are vastly improved, a
javascript-powered search feature is provided, and a full
index of all classes, functions and members is provided.
- setup.py now imports setuptools only optionally. If not
present, distutils is used. The new "pip" installer is
recommended over easy_install as it installs in a more
simplified way.
- added an extremely basic illustration of a PostGIS integration
to the examples folder.
- orm
- Query.with_polymorphic() now accepts a third argument
"discriminator" which will replace the value of
mapper.polymorphic_on for that query. Mappers themselves no
longer require polymorphic_on to be set, even if the mapper
has a polymorphic_identity. When not set, the mapper will
load non-polymorphically by default. Together, these two
features allow a non-polymorphic concrete inheritance setup to
use polymorphic loading on a per-query basis, since concrete
setups are prone to many issues when used polymorphically in
all cases.
- dynamic_loader accepts a query_class= to customize the Query
classes used for both the dynamic collection and the queries
built from it.
- query.order_by() accepts None which will remove any pending
order_by state from the query, as well as cancel out any
mapper/relation configured ordering. This is primarily useful
for overriding the ordering specified on a dynamic_loader().
[ticket:1079]
- sql
- RowProxy objects can be used in place of dictionary arguments
sent to connection.execute() and friends. [ticket:935]
- dialect
- Added a new description_encoding attribute on the dialect that
is used for encoding the column name when processing the
metadata. This usually defaults to utf-8.
- mssql
- Added in a new MSGenericBinary type. This maps to the Binary
type so it can implement the specialized behavior of treating
length specified types as fixed-width Binary types and
non-length types as an unbound variable length Binary type.
- Added in new types: MSVarBinary and MSImage. [ticket:1249]
- Added in the MSReal, MSNText, MSSmallDateTime, MSTime,
MSDateTimeOffset, and MSDateTime2 types
- sqlite
- Table reflection now stores the actual DefaultClause value for
the column. [ticket:1266]
- bugfixes, behavioral changes
- general
- orm
- Exceptions raised during compile_mappers() are now preserved
to provide "sticky behavior" - if a hasattr() call on a
pre-compiled mapped attribute triggers a failing compile and
suppresses the exception, subsequent compilation is blocked
and the exception will be reiterated on the next compile()
call. This issue occurs frequently when using declarative.
- property.of_type() is now recognized on a single-table
inheriting target, when used in the context of
prop.of_type(..).any()/has(), as well as
query.join(prop.of_type(...)).
- query.join() raises an error when the target of the join
doesn't match the property-based attribute - while it's
unlikely anyone is doing this, the SQLAlchemy author was
guilty of this particular loosey-goosey behavior.
- Fixed bug when using weak_instance_map=False where modified
events would not be intercepted for a flush(). [ticket:1272]
- Fixed some deep "column correspondence" issues which could
impact a Query made against a selectable containing multiple
versions of the same table, as well as unions and similar
which contained the same table columns in different column
positions at different levels. [ticket:1268]
- Custom comparator classes used in conjunction with
column_property(), relation() etc. can define new comparison
methods on the Comparator, which will become available via
__getattr__() on the InstrumentedAttribute. In the case of
synonym() or comparable_property(), attributes are resolved
first on the user-defined descriptor, then on the user-defined
comparator.
- Added ScopedSession.is_active accessor. [ticket:976]
- Can pass mapped attributes and column objects as keys to
query.update({}). [ticket:1262]
- Mapped attributes passed to the values() of an expression
level insert() or update() will use the keys of the mapped
columns, not that of the mapped attribute.
- Corrected problem with Query.delete() and Query.update() not
working properly with bind parameters. [ticket:1242]
- Query.select_from(), from_statement() ensure that the given
argument is a FromClause, or Text/Select/Union, respectively.
- Query() can be passed a "composite" attribute as a column
expression and it will be expanded. Somewhat related to
[ticket:1253].
- Query() is a little more robust when passed various column
expressions such as strings, clauselists, text() constructs
(which may mean it just raises an error more nicely).
- first() works as expected with Query.from_statement().
- Fixed bug introduced in 0.5rc4 involving eager loading not
functioning for properties which were added to a mapper
post-compile using add_property() or equivalent.
- Fixed bug where many-to-many relation() with viewonly=True
would not correctly reference the link between
secondary->remote.
- Duplicate items in a list-based collection will be maintained
when issuing INSERTs to a "secondary" table in a many-to-many
relation. Assuming the m2m table has a unique or primary key
constraint on it, this will raise the expected constraint
violation instead of silently dropping the duplicate
entries. Note that the old behavior remains for a one-to-many
relation since collection entries in that case don't result in
INSERT statements and SQLA doesn't manually police
collections. [ticket:1232]
- Query.add_column() can accept FromClause objects in the same
manner as session.query() can.
- Comparison of many-to-one relation to NULL is properly
converted to IS NOT NULL based on not_().
- Extra checks added to ensure explicit
primaryjoin/secondaryjoin are ClauseElement instances, to
prevent more confusing errors later on. [ticket:1087]
- Improved mapper() check for non-class classes. [ticket:1236]
- comparator_factory argument is now documented and supported by
all MapperProperty types, including column_property(),
relation(), backref(), and synonym() [ticket:5051].
- Changed the name of PropertyLoader to RelationProperty, to be
consistent with all the other names. PropertyLoader is still
present as a synonym.
- fixed "double iter()" call causing bus errors in shard API,
removed errant result.close() left over from the 0.4
version. [ticket:1099] [ticket:1228]
- made Session.merge cascades not trigger autoflush. Fixes
merged instances getting prematurely inserted with missing
values.
- Two fixes to help prevent out-of-band columns from being
rendered in polymorphic_union inheritance scenarios (which
then causes extra tables to be rendered in the FROM clause
causing cartesian products):
- improvements to "column adaption" for a->b->c inheritance
situations to better locate columns that are related to
one another via multiple levels of indirection, rather
than rendering the non-adapted column.
- the "polymorphic discriminator" column is only rendered
for the actual mapper being queried against. The column
won't be "pulled in" from a subclass or superclass mapper
since it's not needed.
- Fixed shard_id argument on ShardedSession.execute().
[ticket:1072]
- sql
- Columns can again contain percent signs within their
names. [ticket:1256]
- sqlalchemy.sql.expression.Function is now a public class. It
can be subclassed to provide user-defined SQL functions in an
imperative style, including with pre-established behaviors.
The postgis.py example illustrates one usage of this.
- PickleType now favors == comparison by default, if the
incoming object (such as a dict) implements __eq__(). If the
object does not implement __eq__() and mutable=True, a
deprecation warning is raised.
- Fixed the import weirdness in sqlalchemy.sql to not export
__names__ [ticket:1215].
- Using the same ForeignKey object repeatedly raises an error
instead of silently failing later. [ticket:1238]
- Added NotImplementedError for params() method on
Insert/Update/Delete constructs. These items currently don't
support this functionality, which also would be a little
misleading compared to values().
- Reflected foreign keys will properly locate their referenced
column, even if the column was given a "key" attribute
different from the reflected name. This is achieved via a new
flag on ForeignKey/ForeignKeyConstraint called "link_to_name",
if True means the given name is the referred-to column's name,
not its assigned key. [ticket:650]
- select() can accept a ClauseList as a column in the same way
as a Table or other selectable and the interior expressions
will be used as column elements. [ticket:1253]
- the "passive" flag on session.is_modified() is correctly
propagated to the attribute manager.
- union() and union_all() will not whack any order_by() that has
been applied to the select()s inside. If you union() a
select() with order_by() (presumably to support LIMIT/OFFSET),
you should also call self_group() on it to apply parenthesis.
- engine/pool
- Connection.invalidate() checks for closed status to avoid
attribute errors. [ticket:1246]
- NullPool supports reconnect on failure behavior.
[ticket:1094]
- Added a mutex for the initial pool creation when using
pool.manage(dbapi). This prevents a minor case of "dogpile"
behavior which would otherwise occur upon a heavy load
startup. [ticket:799]
- _execute_clauseelement() goes back to being a private method.
Subclassing Connection is not needed now that ConnectionProxy
is available.
- documentation
- Tickets [ticket:1200] [ticket:1149].
- Added note about create_session() defaults.
- Added section about metadata.reflect().
- Updated `TypeDecorator` section.
- Rewrote the "threadlocal" strategy section of the docs due to
recent confusion over this feature.
- Removed badly out of date 'polymorphic_fetch' and
'select_table' docs from inheritance, reworked the second half
of "joined table inheritance".
- Documented `comparator_factory` kwarg, added new doc section
"Custom Comparators".
- mssql
- Refactored the Date/Time types. The ``smalldatetime`` data
type no longer truncates to a date only, and will now be
mapped to the MSSmallDateTime type. [ticket:1254]
- Corrected an issue with Numerics to accept an int.
- Mapped ``char_length`` to the ``LEN()`` function.
- If an ``INSERT`` includes a subselect the ``INSERT`` is
converted from an ``INSERT INTO VALUES`` construct to a
``INSERT INTO SELECT`` construct.
- If the column is part of a ``primary_key`` it will be ``NOT
NULL`` since MSSQL doesn't allow ``NULL`` in primary_key
columns.
- ``MSBinary`` now returns a ``BINARY`` instead of an
``IMAGE``. This is a backwards incompatible change in that
``BINARY`` is a fixed length data type whereas ``IMAGE`` is a
variable length data type. [ticket:1249]
- ``get_default_schema_name`` is now reflected from the database
based on the user's default schema. This only works with MSSQL
2005 and later. [ticket:1258]
- Added collation support through the use of a new collation
argument. This is supported on the following types: char,
nchar, varchar, nvarchar, text, ntext. [ticket:1248]
- Changes to the connection string parameters favor DSN as the
default specification for pyodbc. See the mssql.py docstring
for detailed usage instructions.
- Added experimental support of savepoints. It currently does
not work fully with sessions.
- Support for three levels of column nullability: NULL, NOT
NULL, and the database's configured default. The default
Column configuration (nullable=True) will now generate NULL in
the DDL. Previously no specification was emitted and the
database default would take effect (usually NULL, but not
always). To explicitly request the database default,
configure columns with nullable=None and no specification will
be emitted in DDL. This is backwards incompatible
behavior. [ticket:1243]
- postgres
- "%" signs in text() constructs are automatically escaped to
"%%". Because of the backwards incompatible nature of this
change, a warning is emitted if '%%' is detected in the
string. [ticket:1267]
- Calling alias.execute() in conjunction with
server_side_cursors won't raise AttributeError.
- Added Index reflection support to PostgreSQL, using a great
patch we long neglected, submitted by Ken
Kuhlman. [ticket:714]
- oracle
- Adjusted the format of create_xid() to repair two-phase
commit. We now have field reports of Oracle two-phase commit
working properly with this change.
- Added OracleNVarchar type, produces NVARCHAR2, and also
subclasses Unicode so that convert_unicode=True by default.
NVARCHAR2 reflects into this type automatically so these
columns pass unicode on a reflected table with no explicit
convert_unicode=True flags. [ticket:1233]
- Fixed bug which was preventing out params of certain types
from being received; thanks a ton to huddlej at wwu.edu !
[ticket:1265]
- mysql
- "%" signs in text() constructs are automatically escaped to
"%%". Because of the backwards incompatible nature of this
change, a warning is emitted if '%%' is detected in the
string.
- Fixed bug in exception raise when FK columns not present
during reflection. [ticket:1241]
- Fixed bug involving reflection of a remote-schema table with a
foreign key ref to another table in that schema.
- associationproxy
- The association proxy properties are make themselves available
at the class level, e.g. MyClass.aproxy. Previously this
evaluated to None.
- declarative
- The full list of arguments accepted as string by backref()
includes 'primaryjoin', 'secondaryjoin', 'secondary',
'foreign_keys', 'remote_side', 'order_by'.
0.5.0rc4
========
- features
- orm
- Query.count() has been enhanced to do the "right thing" in a
wider variety of cases. It can now count multiple-entity
queries, as well as column-based queries. Note that this means
if you say query(A, B).count() without any joining criterion,
it's going to count the cartesian product of A*B. Any query
which is against column-based entities will automatically
issue "SELECT count(1) FROM (SELECT...)" so that the real
rowcount is returned, meaning a query such as
query(func.count(A.name)).count() will return a value of one,
since that query would return one row.
- Lots of performance tuning. A rough guesstimate over various
ORM operations places it 10% faster over 0.5.0rc3, 25-30% over
0.4.8.
- bugfixes and behavioral changes
- general:
- global "propigate"->"propagate" change.
- orm
- Adjustments to the enhanced garbage collection on
InstanceState to better guard against errors due to lost
state.
- Query.get() returns a more informative error message when
executed against multiple entities. [ticket:1220]
- Restored NotImplementedError on Cls.relation.in_()
[ticket:1140] [ticket:1221]
- Fixed PendingDeprecationWarning involving order_by parameter
on relation(). [ticket:1226]
- sql
- Removed the 'properties' attribute of the Connection object,
Connection.info should be used.
- Restored "active rowcount" fetch before ResultProxy autocloses
the cursor. This was removed in 0.5rc3.
- Rearranged the `load_dialect_impl()` method in `TypeDecorator`
such that it will take effect even if the user-defined
`TypeDecorator` uses another `TypeDecorator` as its impl.
- access
- Added support for Currency type.
- Functions were not return their result. [ticket:1017]
- Corrected problem with joins. Access only support LEFT OUTER
or INNER not just JOIN by itself. [ticket:1017]
- mssql
- Lots of cleanup and fixes to correct problems with limit and
offset.
- Correct situation where subqueries as part of a binary
expression need to be translated to use the IN and NOT IN
syntax.
- Fixed E Notation issue that prevented the ability to insert
decimal values less than 1E-6. [ticket:1216]
- Corrected problems with reflection when dealing with schemas,
particularly when those schemas are the default
schema. [ticket:1217]
- Corrected problem with casting a zero length item to a
varchar. It now correctly adjusts the CAST.
- ext
- Can now use a custom "inherit_condition" in __mapper_args__
when using declarative.
- fixed string-based "remote_side", "order_by" and others not
propagating correctly when used in backref().
0.5.0rc3
========
- features
- orm
- Added two new hooks to SessionExtension: after_bulk_delete()
and after_bulk_update(). after_bulk_delete() is called after
a bulk delete() operation on a query. after_bulk_update() is
called after a bulk update() operation on a query.
- sql
- SQL compiler optimizations and complexity reduction. The call
count for compiling a typical select() construct is 20% less
versus 0.5.0rc2.
- Dialects can now generate label names of adjustable
length. Pass in the argument "label_length=<value>" to
create_engine() to adjust how many characters max will be
present in dynamically generated column labels, i.e.
"somecolumn AS somelabel". Any value less than 6 will result
in a label of minimal size, consisting of an underscore and a
numeric counter. The compiler uses the value of
dialect.max_identifier_length as a default. [ticket:1211]
- ext
- Added a new extension sqlalchemy.ext.serializer. Provides
Serializer/Deserializer "classes" which mirror
Pickle/Unpickle, as well as dumps() and loads(). This
serializer implements an "external object" pickler which keeps
key context-sensitive objects, including engines, sessions,
metadata, Tables/Columns, and mappers, outside of the pickle
stream, and can later restore the pickle using any
engine/metadata/session provider. This is used not for
pickling regular object instances, which are pickleable
without any special logic, but for pickling expression objects
and full Query objects, such that all mapper/engine/session
dependencies can be restored at unpickle time.
- oracle
- Wrote a docstring for Oracle dialect. Apparently that Ohloh
"few source code comments" label is starting to sting :).
- Removed FIRST_ROWS() optimize flag when using LIMIT/OFFSET,
can be reenabled with optimize_limits=True create_engine()
flag. [ticket:536]
- bugfixes and behavioral changes
- orm
- "not equals" comparisons of simple many-to-one relation to an
instance will not drop into an EXISTS clause and will compare
foreign key columns instead.
- Removed not-really-working use cases of comparing a collection
to an iterable. Use contains() to test for collection
membership.
- Improved the behavior of aliased() objects such that they more
accurately adapt the expressions generated, which helps
particularly with self-referential comparisons. [ticket:1171]
- Fixed bug involving primaryjoin/secondaryjoin conditions
constructed from class-bound attributes (as often occurs when
using declarative), which later would be inappropriately
aliased by Query, particularly with the various EXISTS based
comparators.
- Fixed bug when using multiple query.join() with an
aliased-bound descriptor which would lose the left alias.
- Improved weakref identity map memory management to no longer
require mutexing, resurrects garbage collected instance on a
lazy basis for an InstanceState with pending changes.
- InstanceState object now removes circular references to itself
upon disposal to keep it outside of cyclic garbage collection.
- relation() won't hide unrelated ForeignKey errors inside of
the "please specify primaryjoin" message when determining join
condition.
- Fixed bug in Query involving order_by() in conjunction with
multiple aliases of the same class (will add tests in
[ticket:1218])
- When using Query.join() with an explicit clause for the ON
clause, the clause will be aliased in terms of the left side
of the join, allowing scenarios like query(Source).
from_self().join((Dest, Source.id==Dest.source_id)) to work
properly.
- polymorphic_union() function respects the "key" of each Column
if they differ from the column's name.
- Repaired support for "passive-deletes" on a many-to-one
relation() with "delete" cascade. [ticket:1183]
- Fixed bug in composite types which prevented a primary-key
composite type from being mutated [ticket:1213].
- Added more granularity to internal attribute access, such that
cascade and flush operations will not initialize unloaded
attributes and collections, leaving them intact for a
lazy-load later on. Backref events still initialize attrbutes
and collections for pending instances. [ticket:1202]
- sql
- Simplified the check for ResultProxy "autoclose without
results" to be based solely on presence of
cursor.description. All the regexp-based guessing about
statements returning rows has been removed [ticket:1212].
- Direct execution of a union() construct will properly set up
result-row processing. [ticket:1194]
- The internal notion of an "OID" or "ROWID" column has been
removed. It's basically not used by any dialect, and the
possibility of its usage with psycopg2's cursor.lastrowid is
basically gone now that INSERT..RETURNING is available.
- Removed "default_order_by()" method on all FromClause objects.
- Repaired the table.tometadata() method so that a passed-in
schema argument is propagated to ForeignKey constructs.
- Slightly changed behavior of IN operator for comparing to
empty collections. Now results in inequality comparison
against self. More portable, but breaks with stored procedures
that aren't pure functions.
- oracle
- Setting the auto_convert_lobs to False on create_engine() will
also instruct the OracleBinary type to return the cx_oracle
LOB object unchanged.
- mysql
- Fixed foreign key reflection in the edge case where a Table's
explicit schema= is the same as the schema (database) the
connection is attached to.
- No longer expects include_columns in table reflection to be
lower case.
- ext
- Fixed bug preventing declarative-bound "column" objects from
being used in column_mapped_collection(). [ticket:1174]
- misc
- util.flatten_iterator() func doesn't interpret strings with
__iter__() methods as iterators, such as in pypy
[ticket:1077].
0.5.0rc2
========
- orm
- Fixed bug involving read/write relation()s that contain
literal or other non-column expressions within their
primaryjoin condition equated to a foreign key column.
- "non-batch" mode in mapper(), a feature which allows mapper
extension methods to be called as each instance is
updated/inserted, now honors the insert order of the objects
given.
- Fixed RLock-related bug in mapper which could deadlock upon
reentrant mapper compile() calls, something that occurs when
using declarative constructs inside of ForeignKey objects.
- ScopedSession.query_property now accepts a query_cls factory,
overriding the session's configured query_cls.
- Fixed shared state bug interfering with ScopedSession.mapper's
ability to apply default __init__ implementations on object
subclasses.
- Fixed up slices on Query (i.e. query[x:y]) to work properly
for zero length slices, slices with None on either end.
[ticket:1177]
- Added an example illustrating Celko's "nested sets" as a
SQLA mapping.
- contains_eager() with an alias argument works even when
the alias is embedded in a SELECT, as when sent to the
Query via query.select_from().
- contains_eager() usage is now compatible with a Query that
also contains a regular eager load and limit/offset, in that
the columns are added to the Query-generated subquery.
[ticket:1180]
- session.execute() will execute a Sequence object passed to
it (regression from 0.4).
- Removed the "raiseerror" keyword argument from object_mapper()
and class_mapper(). These functions raise in all cases
if the given class/instance is not mapped.
- Fixed session.transaction.commit() on a autocommit=False
session not starting a new transaction.
- Some adjustments to Session.identity_map's weak referencing
behavior to reduce asynchronous GC side effects.
- Adjustment to Session's post-flush accounting of newly
"clean" objects to better protect against operating on
objects as they're asynchronously gc'ed. [ticket:1182]
- sql
- column.in_(someselect) can now be used as a columns-clause
expression without the subquery bleeding into the FROM clause
[ticket:1074]
- sqlite
- Overhauled SQLite date/time bind/result processing to use
regular expressions and format strings, rather than
strptime/strftime, to generically support pre-1900 dates,
dates with microseconds. [ticket:968]
- String's (and Unicode's, UnicodeText's, etc.) convert_unicode
logic disabled in the sqlite dialect, to adjust for pysqlite
2.5.0's new requirement that only Python unicode objects are
accepted;
http://itsystementwicklung.de/pipermail/list-pysqlite/2008-March/000018.html
- mysql
- Temporary tables are now reflectable.
- oracle
- Oracle will detect string-based statements which contain
comments at the front before a SELECT as SELECT statements.
[ticket:1187]
0.5.0rc1
========
- orm
- Query now has delete() and update(values) methods. This allows
to perform bulk deletes/updates with the Query object.
- The RowTuple object returned by Query(*cols) now features
keynames which prefer mapped attribute names over column keys,
column keys over column names, i.e. Query(Class.foo,
Class.bar) will have names "foo" and "bar" even if those are
not the names of the underlying Column objects. Direct Column
objects such as Query(table.c.col) will return the "key"
attribute of the Column.
- Added scalar() and value() methods to Query, each return a
single scalar value. scalar() takes no arguments and is
roughly equivalent to first()[0], value()
takes a single column expression and is roughly equivalent to
values(expr).next()[0].
- Improved the determination of the FROM clause when placing SQL
expressions in the query() list of entities. In particular
scalar subqueries should not "leak" their inner FROM objects
out into the enclosing query.
- Joins along a relation() from a mapped class to a mapped
subclass, where the mapped subclass is configured with single
table inheritance, will include an IN clause which limits the
subtypes of the joined class to those requested, within the ON
clause of the join. This takes effect for eager load joins as
well as query.join(). Note that in some scenarios the IN
clause will appear in the WHERE clause of the query as well
since this discrimination has multiple trigger points.
- AttributeExtension has been refined such that the event
is fired before the mutation actually occurs. Additionally,
the append() and set() methods must now return the given value,
which is used as the value to be used in the mutation operation.
This allows creation of validating AttributeListeners which
raise before the action actually occurs, and which can change
the given value into something else before its used.
- column_property(), composite_property(), and relation() now
accept a single or list of AttributeExtensions using the
"extension" keyword argument.
- query.order_by().get() silently drops the "ORDER BY" from
the query issued by GET but does not raise an exception.
- Added a Validator AttributeExtension, as well as a
@validates decorator which is used in a similar fashion
as @reconstructor, and marks a method as validating
one or more mapped attributes.
- class.someprop.in_() raises NotImplementedError pending the
implementation of "in_" for relation [ticket:1140]
- Fixed primary key update for many-to-many collections where
the collection had not been loaded yet [ticket:1127]
- Fixed bug whereby deferred() columns with a group in conjunction
with an otherwise unrelated synonym() would produce
an AttributeError during deferred load.
- The before_flush() hook on SessionExtension takes place before
the list of new/dirty/deleted is calculated for the final
time, allowing routines within before_flush() to further
change the state of the Session before the flush proceeds.
[ticket:1128]
- The "extension" argument to Session and others can now
optionally be a list, supporting events sent to multiple
SessionExtension instances. Session places SessionExtensions
in Session.extensions.
- Reentrant calls to flush() raise an error. This also serves
as a rudimentary, but not foolproof, check against concurrent
calls to Session.flush().
- Improved the behavior of query.join() when joining to
joined-table inheritance subclasses, using explicit join
criteria (i.e. not on a relation).
- @orm.attributes.on_reconstitute and
MapperExtension.on_reconstitute have been renamed to
@orm.reconstructor and MapperExtension.reconstruct_instance
- Fixed @reconstructor hook for subclasses which inherit from a
base class. [ticket:1129]
- The composite() property type now supports a
__set_composite_values__() method on the composite class which
is required if the class represents state using attribute
names other than the column's keynames; default-generated
values now get populated properly upon flush. Also,
composites with attributes set to None compare correctly.
[ticket:1132]
- The 3-tuple of iterables returned by attributes.get_history()
may now be a mix of lists and tuples. (Previously members
were always lists.)
- Fixed bug whereby changing a primary key attribute on an
entity where the attribute's previous value had been expired
would produce an error upon flush(). [ticket:1151]
- Fixed custom instrumentation bug whereby get_instance_dict()
was not called for newly constructed instances not loaded
by the ORM.
- Session.delete() adds the given object to the session if
not already present. This was a regression bug from 0.4.
[ticket:1150]
- The `echo_uow` flag on `Session` is deprecated, and unit-of-work
logging is now application-level only, not per-session level.
- Removed conflicting `contains()` operator from
`InstrumentedAttribute` which didn't accept `escape` kwaarg
[ticket:1153].
- declarative
- Fixed bug whereby mapper couldn't initialize if a composite
primary key referenced another table that was not defined
yet. [ticket:1161]
- Fixed exception throw which would occur when string-based
primaryjoin condition was used in conjunction with backref.
- schema
- Added "sorted_tables" accessor to MetaData, which returns
Table objects sorted in order of dependency as a list.
This deprecates the MetaData.table_iterator() method.
The "reverse=False" keyword argument has also been
removed from util.sort_tables(); use the Python
'reversed' function to reverse the results.
[ticket:1033]
- The 'length' argument to all Numeric types has been renamed
to 'scale'. 'length' is deprecated and is still accepted
with a warning.
- Dropped 0.3-compatibility for user defined types
(convert_result_value, convert_bind_param).
- sql
- Temporarily rolled back the "ORDER BY" enhancement from
[ticket:1068]. This feature is on hold pending further
development.
- The exists() construct won't "export" its contained list
of elements as FROM clauses, allowing them to be used more
effectively in the columns clause of a SELECT.
- and_() and or_() now generate a ColumnElement, allowing
boolean expressions as result columns, i.e.
select([and_(1, 0)]). [ticket:798]
- Bind params now subclass ColumnElement which allows them to be
selectable by orm.query (they already had most ColumnElement
semantics).
- Added select_from() method to exists() construct, which becomes
more and more compatible with a regular select().
- Added func.min(), func.max(), func.sum() as "generic functions",
which basically allows for their return type to be determined
automatically. Helps with dates on SQLite, decimal types,
others. [ticket:1160]
- added decimal.Decimal as an "auto-detect" type; bind parameters
and generic functions will set their type to Numeric when a
Decimal is used.
- mysql
- The 'length' argument to MSInteger, MSBigInteger, MSTinyInteger,
MSSmallInteger and MSYear has been renamed to 'display_width'.
- Added MSMediumInteger type [ticket:1146].
- the function func.utc_timestamp() compiles to UTC_TIMESTAMP, without
the parenthesis, which seem to get in the way when using in
conjunction with executemany().
- oracle
- limit/offset no longer uses ROW NUMBER OVER to limit rows,
and instead uses subqueries in conjunction with a special
Oracle optimization comment. Allows LIMIT/OFFSET to work
in conjunction with DISTINCT. [ticket:536]
- has_sequence() now takes the current "schema" argument into
account [ticket:1155]
- added BFILE to reflected type names [ticket:1121]
0.5beta3
========
0.5beta3 includes all bugfixes listed under release "0.4.7".
- orm
- The "entity_name" feature of SQLAlchemy mappers has been
removed. For rationale, see http://tinyurl.com/6nm2ne
- the "autoexpire" flag on Session, sessionmaker(), and
scoped_session() has been renamed to "expire_on_commit". It
does not affect the expiration behavior of rollback().
- fixed endless loop bug which could occur within a mapper's
deferred load of inherited attributes.
- a legacy-support flag "_enable_transaction_accounting" flag
added to Session which when False, disables all
transaction-level object accounting, including expire on
rollback, expire on commit, new/deleted list maintenance, and
autoflush on begin.
- The 'cascade' parameter to relation() accepts None as a value,
which is equivalent to no cascades.
- A critical fix to dynamic relations allows the "modified"
history to be properly cleared after a flush().
- user-defined @properties on a class are detected and left in
place during mapper initialization. This means that a
table-bound column of the same name will not be mapped at all
if a @property is in the way (and the column is not remapped
to a different name), nor will an instrumented attribute from
an inherited class be applied. The same rules apply for names
excluded using the include_properties/exclude_properties
collections.
- Added a new SessionExtension hook called after_attach(). This
is called at the point of attachment for objects via add(),
add_all(), delete(), and merge().
- A mapper which inherits from another, when inheriting the
columns of its inherited mapper, will use any reassigned
property names specified in that inheriting mapper.
Previously, if "Base" had reassigned "base_id" to the name
"id", "SubBase(Base)" would still get an attribute called
"base_id". This could be worked around by explicitly stating
the column in each submapper as well but this is fairly
unworkable and also impossible when using declarative
[ticket:1111].
- Fixed a series of potential race conditions in Session whereby
asynchronous GC could remove unmodified, no longer referenced
items from the session as they were present in a list of items
to be processed, typically during session.expunge_all() and
dependent methods.
- Some improvements to the _CompileOnAttr mechanism which should
reduce the probability of "Attribute x was not replaced during
compile" warnings. (this generally applies to SQLA hackers,
like Elixir devs).
- Fixed bug whereby the "unsaved, pending instance" FlushError
raised for a pending orphan would not take superclass mappers
into account when generating the list of relations responsible
for the error.
- sql
- func.count() with no arguments renders as COUNT(*), equivalent
to func.count(text('*')).
- simple label names in ORDER BY expressions render as
themselves, and not as a re-statement of their corresponding
expression. This feature is currently enabled only for
SQLite, MySQL, and PostgreSQL. It can be enabled on other
dialects as each is shown to support this
behavior. [ticket:1068]
- ext
- Class-bound attributes sent as arguments to relation()'s
remote_side and foreign_keys parameters are now accepted,
allowing them to be used with declarative. Additionally fixed
bugs involving order_by being specified as a class-bound
attribute in conjunction with eager loading.
- declarative initialization of Columns adjusted so that
non-renamed columns initialize in the same way as a non
declarative mapper. This allows an inheriting mapper to set
up its same-named "id" columns in particular such that the
parent "id" column is favored over the child column, reducing
database round trips when this value is requested.
- mysql
- Quoting of MSEnum values for use in CREATE TABLE is now
optional & will be quoted on demand as required. (Quoting was
always optional for use with existing tables.) [ticket:1110]
0.5beta2
========
0.5beta2 includes some of the bugfixes listed under release "0.4.7".
- orm
- In addition to expired attributes, deferred attributes also
load if their data is present in the result set. [ticket:870]
- session.refresh() raises an informative error message if the
list of attributes does not include any column-based
attributes.
- query() raises an informative error message if no columns or
mappers are specified.
- lazy loaders now trigger autoflush before proceeding. This
allows expire() of a collection or scalar relation to function
properly in the context of autoflush.
- column_property() attributes which represent SQL expressions
or columns that are not present in the mapped tables (such as
those from views) are automatically expired after an INSERT or
UPDATE, assuming they have not been locally modified, so that
they are refreshed with the most recent data upon access.
[ticket:887]
- Fixed explicit, self-referential joins between two
joined-table inheritance mappers when using query.join(cls,
aliased=True). [ticket:1082]
- Fixed query.join() when used in conjunction with a
columns-only clause and an SQL-expression ON clause in the
join.
- The "allow_column_override" flag from mapper() has been
removed. This flag is virtually always misunderstood. Its
specific functionality is available via the
include_properties/exclude_properties mapper arguments.
- Repaired `__str__()` method on Query. [ticket:1066]
- Session.bind gets used as a default even when table/mapper
specific binds are defined.
- schema
- Added prefixes option to `Table` that accepts a list of
strings to insert after CREATE in the CREATE TABLE statement.
[ticket:1075]
- Unicode, UnicodeText types now set "assert_unicode" and
"convert_unicode" by default, but accept overriding
**kwargs for these values.
- sql
- Added new match() operator that performs a full-text search.
Supported on PostgreSQL, SQLite, MySQL, MS-SQL, and Oracle
backends.
- sqlite
- Modified SQLite's representation of "microseconds" to match
the output of str(somedatetime), i.e. in that the microseconds
are represented as fractional seconds in string format. This
makes SQLA's SQLite date type compatible with datetimes that
were saved directly using Pysqlite (which just calls str()).
Note that this is incompatible with the existing microseconds
values in a SQLA 0.4 generated SQLite database file.
To get the old behavior globally:
from sqlalchemy.databases.sqlite import DateTimeMixin
DateTimeMixin.__legacy_microseconds__ = True
To get the behavior on individual DateTime types:
t = sqlite.SLDateTime()
t.__legacy_microseconds__ = True
Then use "t" as the type on the Column.
[ticket:1090]
- SQLite Date, DateTime, and Time types only accept Python
datetime objects now, not strings. If you'd like to format
dates as strings yourself with SQLite, use a String type. If
you'd like them to return datetime objects anyway despite
their accepting strings as input, make a TypeDecorator around
String - SQLA doesn't encourage this pattern.
- extensions
- Declarative supports a __table_args__ class variable, which is
either a dictionary, or tuple of the form (arg1, arg2, ...,
{kwarg1:value, ...}) which contains positional + kw arguments
to be passed to the Table constructor. [ticket:1096]
0.5beta1
========
An ongoing document describing the changes from 0.4 to 0.5 is at:
http://www.sqlalchemy.org/trac/wiki/05Migration
For this section, the list below primarily lists changes within the
attribute instrumentation API and is only a small fraction of the
full changes between 0.4/0.5.
-orm
- The "__init__" trigger/decorator added by mapper now attempts
to exactly mirror the argument signature of the original
__init__. The pass-through for '_sa_session' is no longer
implicit- you must allow for this keyword argument in your
constructor.
- ClassState is renamed to ClassManager.
- Classes may supply their own InstrumentationManager by
providing a __sa_instrumentation_manager__ property.
- Custom instrumentation may use any mechanism to associate a
ClassManager with a class and an InstanceState with an
instance. Attributes on those objects are still the default
association mechanism used by SQLAlchemy's native
instrumentation.
- Moved entity_name, _sa_session_id, and _instance_key from the
instance object to the instance state. These values are still
available in the old way, which is now deprecated, using
descriptors attached to the class. A deprecation warning will
be issued when accessed.
- The _prepare_instrumentation alias for prepare_instrumentation
has been removed.
- sqlalchemy.exceptions has been renamed to sqlalchemy.exc. The
module may be imported under either name.
- ORM-related exceptions are now defined in sqlalchemy.orm.exc.
ConcurrentModificationError, FlushError, and
UnmappedColumnError compatibility aliases are installed in
sqlalchemy.exc during the import of sqlalchemy.orm.
- sqlalchemy.logging has been renamed to sqlalchemy.log.
- The transitional sqlalchemy.log.SADeprecationWarning alias for
the warning's definition in sqlalchemy.exc has been removed.
- exc.AssertionError has been removed and usage replaced with
Python's built-in AssertionError.
- The behavior of MapperExtensions attached to multiple,
entity_name= primary mappers for a single class has been
altered. The first mapper() defined for a class is the only
mapper eligible for the MapperExtension 'instrument_class',
'init_instance' and 'init_failed' events. This is backwards
incompatible; previously the extensions of last mapper defined
would receive these events.
- firebird
- Added support for returning values from inserts (2.0+ only),
updates and deletes (2.1+ only).
For changes prior to 0.5, see CHANGES_PRE_05
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