0.9 Changelog¶
0.9.10¶
Released: July 22, 2015orm¶
Added a new entry
"entity"
to the dictionaries returned byQuery.column_descriptions
. This refers to the primary ORM mapped class or aliased class that is referred to by the expression. Compared to the existing entry for"type"
, it will always be a mapped entity, even if extracted from a column expression, or None if the given expression is a pure core expression. See also #3403 which repaired a regression in this feature which was unreleased in 0.9.10 but was released in the 1.0 version.References: #3320
Query
doesn’t support joins, subselects, or special FROM clauses when using theQuery.update()
orQuery.delete()
methods; instead of silently ignoring these fields if methods likeQuery.join()
orQuery.select_from()
has been called, a warning is emitted. As of 1.0.0b5 this will raise an error.References: #3349
Fixed bug where the state tracking within multiple, nested
Session.begin_nested()
operations would fail to propagate the “dirty” flag for an object that had been updated within the inner savepoint, such that if the enclosing savepoint were rolled back, the object would not be part of the state that was expired and therefore reverted to its database state.References: #3352
engine¶
Added the string value
"none"
to those accepted by thePool.reset_on_return
parameter as a synonym forNone
, so that string values can be used for all settings, allowing utilities likeengine_from_config()
to be usable without issue.References: #3375
sql¶
Added official support for a CTE used by the SELECT present inside of
Insert.from_select()
. This behavior worked accidentally up until 0.9.9, when it no longer worked due to unrelated changes as part of #3248. Note that this is the rendering of the WITH clause after the INSERT, before the SELECT; the full functionality of CTEs rendered at the top level of INSERT, UPDATE, DELETE is a new feature targeted for a later release.References: #3418
Fixed issue where a
MetaData
object that used a naming convention would not properly work with pickle. The attribute was skipped leading to inconsistencies and failures if the unpickledMetaData
object were used to base additional tables from.References: #3362
postgresql¶
Fixed a long-standing bug where the
Enum
type as used with the psycopg2 dialect in conjunction with non-ascii values andnative_enum=False
would fail to decode return results properly. This stemmed from when the PGENUM
type used to be a standalone type without a “non native” option.References: #3354
mysql¶
Fixed unicode support for PyMySQL when using an “executemany” operation with unicode parameters. SQLAlchemy now passes both the statement as well as the bound parameters as unicode objects, as PyMySQL generally uses string interpolation internally to produce the final statement, and in the case of executemany does the “encode” step only on the final statement.
References: #3337
Fixed the
BIT
type on Py3K which was not using theord()
function correctly. Pull request courtesy David Marin.References: #3333
sqlite¶
Fixed bug in SQLite dialect where reflection of UNIQUE constraints that included non-alphabetic characters in the names, like dots or spaces, would not be reflected with their name.
References: #3495
tests¶
Fixed an import that prevented “pypy setup.py test” from working correctly.
References: #3406
misc¶
Fixed bug where when using extended attribute instrumentation system, the correct exception would not be raised when
class_mapper()
were called with an invalid input that also happened to not be weak referencable, such as an integer.References: #3408
Fixed regression from 0.9.9 where the
as_declarative()
symbol was removed from thesqlalchemy.ext.declarative
namespace.References: #3324
0.9.9¶
Released: March 10, 2015orm¶
Added new parameter
Session.connection.execution_options
which may be used to set up execution options on aConnection
when it is first checked out, before the transaction has begun. This is used to set up options such as isolation level on the connection before the transaction starts.See also
Setting Transaction Isolation Levels / DBAPI AUTOCOMMIT - new documentation section detailing best practices for setting transaction isolation with sessions.
References: #3296
Added new method
Session.invalidate()
, functions similarly toSession.close()
, except also callsConnection.invalidate()
on all connections, guaranteeing that they will not be returned to the connection pool. This is useful in situations e.g. dealing with gevent timeouts when it is not safe to use the connection further, even for rollbacks.Fixed bugs in ORM object comparisons where comparison of many-to-one
!= None
would fail if the source were an aliased class, or if the query needed to apply special aliasing to the expression due to aliased joins or polymorphic querying; also fixed bug in the case where comparing a many-to-one to an object state would fail if the query needed to apply special aliasing due to aliased joins or polymorphic querying.References: #3310
Fixed bug where internal assertion would fail in the case where an
after_rollback()
handler for aSession
incorrectly adds state to thatSession
within the handler, and the task to warn and remove this state (established by #2389) attempts to proceed.References: #3309
Fixed bug where TypeError raised when
Query.join()
called with unknown kw arguments would raise its own TypeError due to broken formatting. Pull request courtesy Malthe Borch.Fixed bug in lazy loading SQL construction whereby a complex primaryjoin that referred to the same “local” column multiple times in the “column that points to itself” style of self-referential join would not be substituted in all cases. The logic to determine substitutions here has been reworked to be more open-ended.
References: #3300
The “wildcard” loader options, in particular the one set up by the
load_only()
option to cover all attributes not explicitly mentioned, now takes into account the superclasses of a given entity, if that entity is mapped with inheritance mapping, so that attribute names within the superclasses are also omitted from the load. Additionally, the polymorphic discriminator column is unconditionally included in the list, just in the same way that primary key columns are, so that even with load_only() set up, polymorphic loading of subtypes continues to function correctly.References: #3287
Fixed bug where if an exception were thrown at the start of a
Query
before it fetched results, particularly when row processors can’t be formed, the cursor would stay open with results pending and not actually be closed. This is typically only an issue on an interpreter like PyPy where the cursor isn’t immediately GC’ed, and can in some circumstances lead to transactions/ locks being open longer than is desirable.References: #3285
Fixed a leak which would occur in the unsupported and highly non-recommended use case of replacing a relationship on a fixed mapped class many times, referring to an arbitrarily growing number of target mappers. A warning is emitted when the old relationship is replaced, however if the mapping were already used for querying, the old relationship would still be referenced within some registries.
References: #3251
Fixed bug regarding expression mutations which could express itself as a “Could not locate column” error when using
Query
to select from multiple, anonymous column entities when querying against SQLite, as a side effect of the “join rewriting” feature used by the SQLite dialect.References: #3241
Fixed bug where the ON clause for
Query.join()
, andQuery.outerjoin()
to a single-inheritance subclass usingof_type()
would not render the “single table criteria” in the ON clause if thefrom_joinpoint=True
flag were set.References: #3232
examples¶
Updated the Versioning with a History Table example such that mapped columns are re-mapped to match column names as well as grouping of columns; in particular, this allows columns that are explicitly grouped in a same-column-named joined inheritance scenario to be mapped in the same way in the history mappings, avoiding warnings added in the 0.9 series regarding this pattern and allowing the same view of attribute keys.
Fixed a bug in the examples/generic_associations/discriminator_on_association.py example, where the subclasses of AddressAssociation were not being mapped as “single table inheritance”, leading to problems when trying to use the mappings further.
engine¶
Added new user-space accessors for viewing transaction isolation levels;
Connection.get_isolation_level()
,Connection.default_isolation_level
.Fixed bug in
Connection
and pool where theConnection.invalidate()
method, or an invalidation due to a database disconnect, would fail if theisolation_level
parameter had been used withConnection.execution_options()
; the “finalizer” that resets the isolation level would be called on the no longer opened connection.References: #3302
A warning is emitted if the
isolation_level
parameter is used withConnection.execution_options()
when aTransaction
is in play; DBAPIs and/or SQLAlchemy dialects such as psycopg2, MySQLdb may implicitly rollback or commit the transaction, or not change the setting til next transaction, so this is never safe.References: #3296
sql¶
Added the
native_enum
flag to the__repr__()
output ofEnum
, which is mostly important when using it with Alembic autogenerate. Pull request courtesy Dimitris Theodorou.Fixed bug where using a
TypeDecorator
that implemented a type that was also aTypeDecorator
would fail with Python’s “Cannot create a consistent method resolution order (MRO)” error, when any kind of SQL comparison expression were used against an object using this type.References: #3278
Fixed issue where the columns from a SELECT embedded in an INSERT, either through the values clause or as a “from select”, would pollute the column types used in the result set produced by the RETURNING clause when columns from both statements shared the same name, leading to potential errors or mis-adaptation when retrieving the returning rows.
References: #3248
schema¶
Fixed bug in 0.9’s foreign key setup system, such that the logic used to link a
ForeignKey
to its parent could fail when the foreign key used “link_to_name=True” in conjunction with a targetTable
that would not receive its parent column until later, such as within a reflection + “useexisting” scenario, if the target column in fact had a key value different from its name, as would occur in reflection if column reflect events were used to alter the .key of reflectedColumn
objects so that the link_to_name becomes significant. Also repaired support for column type via FK transmission in a similar way when target columns had a different key and were referenced using link_to_name.
postgresql¶
Added support for the
CONCURRENTLY
keyword with PostgreSQL indexes, established usingpostgresql_concurrently
. Pull request courtesy Iuri de Silvio.See also
postgresql_index_concurrently
Repaired support for PostgreSQL UUID types in conjunction with the ARRAY type when using psycopg2. The psycopg2 dialect now employs use of the psycopg2.extras.register_uuid() hook so that UUID values are always passed to/from the DBAPI as UUID() objects. The
UUID.as_uuid
flag is still honored, except with psycopg2 we need to convert returned UUID objects back into strings when this is disabled.References: #2940
Added support for the
postgresql.JSONB
datatype when using psycopg2 2.5.4 or greater, which features native conversion of JSONB data so that SQLAlchemy’s converters must be disabled; additionally, the newly added psycopg2 extensionextras.register_default_jsonb
is used to establish a JSON deserializer passed to the dialect via thejson_deserializer
argument. Also repaired the PostgreSQL integration tests which weren’t actually round-tripping the JSONB type as opposed to the JSON type. Pull request courtesy Mateusz Susik.Repaired the use of the “array_oid” flag when registering the HSTORE type with older psycopg2 versions < 2.4.3, which does not support this flag, as well as use of the native json serializer hook “register_default_json” with user-defined
json_deserializer
on psycopg2 versions < 2.5, which does not include native json.Fixed bug where PostgreSQL dialect would fail to render an expression in an
Index
that did not correspond directly to a table-bound column; typically when atext()
construct was one of the expressions within the index; or could misinterpret the list of expressions if one or more of them were such an expression.References: #3174
mysql¶
The
gaerdbms
dialect is no longer necessary, and emits a deprecation warning. Google now recommends using the MySQLdb dialect directly.References: #3275
Added a version check to the MySQLdb dialect surrounding the check for ‘utf8_bin’ collation, as this fails on MySQL server < 5.0.
References: #3274
sqlite¶
Added support for partial indexes (e.g. with a WHERE clause) on SQLite. Pull request courtesy Kai Groner.
See also
sqlite_partial_index
Added a new SQLite backend for the SQLCipher backend. This backend provides for encrypted SQLite databases using the pysqlcipher Python driver, which is very similar to the pysqlite driver.
See also
pysqlcipher
misc¶
Fixed bug where the association proxy list class would not interpret slices correctly under Py3K. Pull request courtesy Gilles Dartiguelongue.
0.9.8¶
Released: October 13, 2014orm¶
Fixed bug that affected generally the same classes of event as that of #3199, when the
named=True
parameter would be used. Some events would fail to register, and others would not invoke the event arguments correctly, generally in the case of when an event was “wrapped” for adaption in some other way. The “named” mechanics have been rearranged to not interfere with the argument signature expected by internal wrapper functions.References: #3197
Fixed bug that affected many classes of event, particularly ORM events but also engine events, where the usual logic of “de duplicating” a redundant call to
listen()
with the same arguments would fail, for those events where the listener function is wrapped. An assertion would be hit within registry.py. This assertion has now been integrated into the deduplication check, with the added bonus of a simpler means of checking deduplication across the board.References: #3199
Fixed warning that would emit when a complex self-referential primaryjoin contained functions, while at the same time remote_side was specified; the warning would suggest setting “remote side”. It now only emits if remote_side isn’t present.
References: #3194
orm declarative¶
Fixed “‘NoneType’ object has no attribute ‘concrete’” error when using
AbstractConcreteBase
in conjunction with a subclass that declares__abstract__
.References: #3185
engine¶
The execution options passed to an
Engine
either viacreate_engine.execution_options
orEngine.update_execution_options()
are not passed to the specialConnection
used to initialize the dialect within the “first connect” event; dialects will usually perform their own queries in this phase, and none of the current available options should be applied here. In particular, the “autocommit” option was causing an attempt to autocommit within this initial connect which would fail with an AttributeError due to the non-standard state of theConnection
.References: #3200
The string keys that are used to determine the columns impacted for an INSERT or UPDATE are now sorted when they contribute towards the “compiled cache” cache key. These keys were previously not deterministically ordered, meaning the same statement could be cached multiple times on equivalent keys, costing both in terms of memory as well as performance.
References: #3165
sql¶
Fixed bug where a fair number of SQL elements within the sql package would fail to
__repr__()
successfully, due to a missingdescription
attribute that would then invoke a recursion overflow when an internal AttributeError would then re-invoke__repr__()
.References: #3195
An adjustment to table/index reflection such that if an index reports a column that isn’t found to be present in the table, a warning is emitted and the column is skipped. This can occur for some special system column situations as has been observed with Oracle.
References: #3180
Fixed bug in CTE where
literal_binds
compiler argument would not be always be correctly propagated when one CTE referred to another aliased CTE in a statement.References: #3154
Fixed 0.9.7 regression caused by #3067 in conjunction with a mis-named unit test such that so-called “schema” types like
Boolean
andEnum
could no longer be pickled.
postgresql¶
Support is added for “sane multi row count” with the pg8000 driver, which applies mostly to when using versioning with the ORM. The feature is version-detected based on pg8000 1.9.14 or greater in use. Pull request courtesy Tony Locke.
A revisit to this issue first patched in 0.9.5, apparently psycopg2’s
.closed
accessor is not as reliable as we assumed, so we have added an explicit check for the exception messages “SSL SYSCALL error: Bad file descriptor” and “SSL SYSCALL error: EOF detected” when detecting an is-disconnect scenario. We will continue to consult psycopg2’s connection.closed as a first check.References: #3021
Fixed bug where PostgreSQL JSON type was not able to persist or otherwise render a SQL NULL column value, rather than a JSON-encoded
'null'
. To support this case, changes are as follows:The value
null()
can now be specified, which will always result in a NULL value resulting in the statement.A new parameter
JSON.none_as_null
is added, which when True indicates that the PythonNone
value should be persisted as SQL NULL, rather than JSON-encoded'null'
.
Retrieval of NULL as None is also repaired for DBAPIs other than psycopg2, namely pg8000.
References: #3159
The exception wrapping system for DBAPI errors can now accommodate non-standard DBAPI exceptions, such as the psycopg2 TransactionRollbackError. These exceptions will now be raised using the closest available subclass in
sqlalchemy.exc
, in the case of TransactionRollbackError,sqlalchemy.exc.OperationalError
.References: #3075
Fixed bug in
array
object where comparison to a plain Python list would fail to use the correct array constructor. Pull request courtesy Andrew.References: #3141
Added a supported
FunctionElement.alias()
method to functions, e.g. thefunc
construct. Previously, behavior for this method was undefined. The current behavior mimics that of pre-0.9.4, which is that the function is turned into a single-column FROM clause with the given alias name, where the column itself is anonymously named.References: #3137
mysql¶
Mysqlconnector as of version 2.0, probably as a side effect of the python 3 merge, now does not expect percent signs (e.g. as used as the modulus operator and others) to be doubled, even when using the “pyformat” bound parameter format (this change is not documented by Mysqlconnector). The dialect now checks for py2k and for mysqlconnector less than version 2.0 when detecting if the modulus operator should be rendered as
%%
or%
.Unicode SQL is now passed for MySQLconnector version 2.0 and above; for Py2k and MySQL < 2.0, strings are encoded.
sqlite¶
When selecting from a UNION using an attached database file, the pysqlite driver reports column names in cursor.description as ‘dbname.tablename.colname’, instead of ‘tablename.colname’ as it normally does for a UNION (note that it’s supposed to just be ‘colname’ for both, but we work around it). The column translation logic here has been adjusted to retrieve the rightmost token, rather than the second token, so it works in both cases. Workaround courtesy Tony Roberts.
References: #3211
mssql¶
Fixed the version string detection in the pymssql dialect to work with Microsoft SQL Azure, which changes the word “SQL Server” to “SQL Azure”.
References: #3151
oracle¶
Fixed long-standing bug in Oracle dialect where bound parameter names that started with numbers would not be quoted, as Oracle doesn’t like numerics in bound parameter names.
References: #2138
misc¶
Fixed an unlikely race condition observed in some exotic end-user setups, where the attempt to check for “duplicate class name” in declarative would hit upon a not-totally-cleaned-up weak reference related to some other class being removed; the check here now ensures the weakref still references an object before calling upon it further.
References: #3208
Fixed bug in ordering list where the order of items would be thrown off during a collection replace event, if the reorder_on_append flag were set to True. The fix ensures that the ordering list only impacts the list that is explicitly associated with the object.
References: #3191
Fixed bug where
MutableDict
failed to implement theupdate()
dictionary method, thus not catching changes. Pull request courtesy Matt Chisholm.Fixed bug where a custom subclass of
MutableDict
would not show up in a “coerce” operation, and would instead return a plainMutableDict
. Pull request courtesy Matt Chisholm.Fixed bug in connection pool logging where the “connection checked out” debug logging message would not emit if the logging were set up using
logging.setLevel()
, rather than using theecho_pool
flag. Tests to assert this logging have been added. This is a regression that was introduced in 0.9.0.References: #3168
0.9.7¶
Released: July 22, 2014orm¶
Fixed a regression caused by #2976 released in 0.9.4 where the “outer join” propagation along a chain of joined eager loads would incorrectly convert an “inner join” along a sibling join path into an outer join as well, when only descendant paths should be receiving the “outer join” propagation; additionally, fixed related issue where “nested” join propagation would take place inappropriately between two sibling join paths.
References: #3131
Fixed a regression from 0.9.0 due to #2736 where the
Query.select_from()
method no longer set up the “from entity” of theQuery
object correctly, so that subsequentQuery.filter_by()
orQuery.join()
calls would fail to check the appropriate “from” entity when searching for attributes by string name.The “evaluator” for query.update()/delete() won’t work with multi-table updates, and needs to be set to synchronize_session=False or synchronize_session=’fetch’; a warning is now emitted. In 1.0 this will be promoted to a full exception.
References: #3117
Fixed bug where items that were persisted, deleted, or had a primary key change within a savepoint block would not participate in being restored to their former state (not in session, in session, previous PK) after the outer transaction were rolled back.
References: #3108
Fixed bug in subquery eager loading in conjunction with
with_polymorphic()
, the targeting of entities and columns in the subquery load has been made more accurate with respect to this type of entity and others.References: #3106
Fixed bug involving dynamic attributes, that was again a regression of #3060 from version 0.9.5. A self-referential relationship with lazy=’dynamic’ would raise a TypeError within a flush operation.
References: #3099
engine¶
Added new event
ConnectionEvents.handle_error()
, a more fully featured and comprehensive replacement forConnectionEvents.dbapi_error()
.References: #3076
sql¶
Fixed bug in
Enum
and otherSchemaType
subclasses where direct association of the type with aMetaData
would lead to a hang when events (like create events) were emitted on theMetaData
.This change is also backported to: 0.8.7
References: #3124
Fixed a bug within the custom operator plus
TypeEngine.with_variant()
system, whereby using aTypeDecorator
in conjunction with variant would fail with an MRO error when a comparison operator was used.This change is also backported to: 0.8.7
References: #3102
Fix bug in naming convention feature where using a check constraint convention that includes
constraint_name
would then force allBoolean
andEnum
types to require names as well, as these implicitly create a constraint, even if the ultimate target backend were one that does not require generation of the constraint such as PostgreSQL. The mechanics of naming conventions for these particular constraints has been reorganized such that the naming determination is done at DDL compile time, rather than at constraint/table construction time.References: #3067
Fixed bug in common table expressions whereby positional bound parameters could be expressed in the wrong final order when CTEs were nested in certain ways.
References: #3090
Fixed bug where multi-valued
Insert
construct would fail to check subsequent values entries beyond the first one given for literal SQL expressions.References: #3069
Added a “str()” step to the dialect_kwargs iteration for Python version < 2.6.5, working around the “no unicode keyword arg” bug as these args are passed along as keyword args within some reflection processes.
References: #3123
The
TypeEngine.with_variant()
method will now accept a type class as an argument which is internally converted to an instance, using the same convention long established by other constructs such asColumn
.References: #3122
postgresql¶
Added kw argument
postgresql_regconfig
to theColumnOperators.match()
operator, allows the “reg config” argument to be specified to theto_tsquery()
function emitted. Pull request courtesy Jonathan Vanasco.References: #3078
Added support for PostgreSQL JSONB via
JSONB
. Pull request courtesy Damian Dimmich.Fixed bug introduced in 0.9.5 by new pg8000 isolation level feature where engine-level isolation level parameter would raise an error on connect.
References: #3134
mysql¶
MySQL error 2014 “commands out of sync” appears to be raised as a ProgrammingError, not OperationalError, in modern MySQL-Python versions; all MySQL error codes that are tested for “is disconnect” are now checked within OperationalError and ProgrammingError regardless.
This change is also backported to: 0.8.7
References: #3101
sqlite¶
Fixed a SQLite join rewriting issue where a subquery that is embedded as a scalar subquery such as within an IN would receive inappropriate substitutions from the enclosing query, if the same table were present inside the subquery as were in the enclosing query such as in a joined inheritance scenario.
References: #3130
mssql¶
Enabled “multivalues insert” for SQL Server 2008. Pull request courtesy Albert Cervin. Also expanded the checks for “IDENTITY INSERT” mode to include when the identity key is present in the VALUEs clause of the statement.
Added statement encoding to the “SET IDENTITY_INSERT” statements which operate when an explicit INSERT is being interjected into an IDENTITY column, to support non-ascii table identifiers on drivers such as pyodbc + unix + py2k that don’t support unicode statements.
This change is also backported to: 0.8.7
In the SQL Server pyodbc dialect, repaired the implementation for the
description_encoding
dialect parameter, which when not explicitly set was preventing cursor.description from being parsed correctly in the case of result sets that contained names in alternate encodings. This parameter shouldn’t be needed going forward.This change is also backported to: 0.8.7
References: #3091
Fixed a regression from 0.9.5 caused by #3025 where the query used to determine “default schema” is invalid in SQL Server 2000. For SQL Server 2000 we go back to defaulting to the “schema name” parameter of the dialect, which is configurable but defaults to ‘dbo’.
References: #3025
oracle¶
Fixed bug in oracle dialect test suite where in one test, ‘username’ was assumed to be in the database URL, even though this might not be the case.
References: #3128
tests¶
Fixed bug where “python setup.py test” wasn’t calling into distutils appropriately, and errors would be emitted at the end of the test suite.
misc¶
Fixed bug when the declarative
__abstract__
flag was not being distinguished for when it was actually the valueFalse
. The__abstract__
flag needs to actually evaluate to a True value at the level being tested.References: #3097
0.9.6¶
Released: June 23, 2014orm¶
0.9.5¶
Released: June 23, 2014orm¶
The “primaryjoin” model has been stretched a bit further to allow a join condition that is strictly from a single column to itself, translated through some kind of SQL function or expression. This is kind of experimental, but the first proof of concept is a “materialized path” join condition where a path string is compared to itself using “like”. The
ColumnOperators.like()
operator has also been added to the list of valid operators to use in a primaryjoin condition.References: #3029
Added new utility function
make_transient_to_detached()
which can be used to manufacture objects that behave as though they were loaded from a session, then detached. Attributes that aren’t present are marked as expired, and the object can be added to a Session where it will act like a persistent one.References: #3017
Fixed bug in subquery eager loading where a long chain of eager loads across a polymorphic-subclass boundary in conjunction with polymorphic loading would fail to locate the subclass-link in the chain, erroring out with a missing property name on an
AliasedClass
.This change is also backported to: 0.8.7
References: #3055
Fixed ORM bug where the
class_mapper()
function would mask AttributeErrors or KeyErrors that should raise during mapper configuration due to user errors. The catch for attribute/keyerror has been made more specific to not include the configuration step.This change is also backported to: 0.8.7
References: #3047
Additional checks have been added for the case where an inheriting mapper is implicitly combining one of its column-based attributes with that of the parent, where those columns normally don’t necessarily share the same value. This is an extension of an existing check that was added via #1892; however this new check emits only a warning, instead of an exception, to allow for applications that may be relying upon the existing behavior.
References: #3042
Modified the behavior of
load_only()
such that primary key columns are always added to the list of columns to be “undeferred”; otherwise, the ORM can’t load the row’s identity. Apparently, one can defer the mapped primary keys and the ORM will fail, that hasn’t been changed. But as load_only is essentially saying “defer all but X”, it’s more critical that PK cols not be part of this deferral.References: #3080
Fixed a few edge cases which arise in the so-called “row switch” scenario, where an INSERT/DELETE can be turned into an UPDATE. In this situation, a many-to-one relationship set to None, or in some cases a scalar attribute set to None, may not be detected as a net change in value, and therefore the UPDATE would not reset what was on the previous row. This is due to some as-yet unresolved side effects of the way attribute history works in terms of implicitly assuming None isn’t really a “change” for a previously un-set attribute. See also #3061.
Note
This change has been REVERTED in 0.9.6. The full fix will be in version 1.0 of SQLAlchemy.
References: #3060
Related to #3060, an adjustment has been made to the unit of work such that loading for related many-to-one objects is slightly more aggressive, in the case of a graph of self-referential objects that are to be deleted; the load of related objects is to help determine the correct order for deletion if passive_deletes is not set.
Fixed bug in SQLite join rewriting where anonymized column names due to repeats would not correctly be rewritten in subqueries. This would affect SELECT queries with any kind of subquery + join.
References: #3057
Fixes to the newly enhanced boolean coercion in #2804 where the new rules for “where” and “having” wouldn’t take effect for the “whereclause” and “having” kw arguments of the
select()
construct, which is also whatQuery
uses so wasn’t working in the ORM either.References: #3013
examples¶
Added a new example illustrating materialized paths, using the latest relationship features. Example courtesy Jack Zhou.
engine¶
Fixed bug which would occur if a DBAPI exception occurs when the engine first connects and does its initial checks, and the exception is not a disconnect exception, yet the cursor raises an error when we try to close it. In this case the real exception would be quashed as we tried to log the cursor close exception via the connection pool and failed, as we were trying to access the pool’s logger in a way that is inappropriate in this very specific scenario.
References: #3063
Fixed some “double invalidate” situations were detected where a connection invalidation could occur within an already critical section like a connection.close(); ultimately, these conditions are caused by the change in #2907, in that the “reset on return” feature calls out to the Connection/Transaction in order to handle it, where “disconnect detection” might be caught. However, it’s possible that the more recent change in #2985 made it more likely for this to be seen as the “connection invalidate” operation is much quicker, as the issue is more reproducible on 0.9.4 than 0.9.3.
Checks are now added within any section that an invalidate might occur to halt further disallowed operations on the invalidated connection. This includes two fixes both at the engine level and at the pool level. While the issue was observed with highly concurrent gevent cases, it could in theory occur in any kind of scenario where a disconnect occurs within the connection close operation.
References: #3043
sql¶
Liberalized the contract for
Index
a bit in that you can specify atext()
expression as the target; the index no longer needs to have a table-bound column present if the index is to be manually added to the table, either via inline declaration or viaTable.append_constraint()
.References: #3028
Added new flag
between.symmetric
, when set to True renders “BETWEEN SYMMETRIC”. Also added a new negation operator “notbetween_op”, which now allows an expression like~col.between(x, y)
to render as “col NOT BETWEEN x AND y”, rather than a parenthesized NOT string.References: #2990
Fixed bug in INSERT..FROM SELECT construct where selecting from a UNION would wrap the union in an anonymous (e.g. unlabeled) subquery.
This change is also backported to: 0.8.7
References: #3044
Fixed bug where
Table.update()
andTable.delete()
would produce an empty WHERE clause when an emptyand_()
oror_()
or other blank expression were applied. This is now consistent with that ofselect()
.This change is also backported to: 0.8.7
References: #3045
The
Column.nullable
flag is implicitly set toFalse
when thatColumn
is referred to in an explicitPrimaryKeyConstraint
for that table. This behavior now matches that of when theColumn
itself has theColumn.primary_key
flag set toTrue
, which is intended to be an exactly equivalent case.References: #3023
Fixed bug where the
Operators.__and__()
,Operators.__or__()
andOperators.__invert__()
operator overload methods could not be overridden within a customComparator
implementation.References: #3012
Fixed bug in new
DialectKWArgs.argument_for()
method where adding an argument for a construct not previously included for any special arguments would fail.References: #3024
Fixed regression introduced in 0.9 where new “ORDER BY <labelname>” feature from #1068 would not apply quoting rules to the label name as rendered in the ORDER BY.
Restored the import for
Function
to thesqlalchemy.sql.expression
import namespace, which was removed at the beginning of 0.9.
postgresql¶
Added support for AUTOCOMMIT isolation level when using the pg8000 DBAPI. Pull request courtesy Tony Locke.
Added a new flag
ARRAY.zero_indexes
to the PostgreSQLARRAY
type. When set toTrue
, a value of one will be added to all array index values before passing to the database, allowing better interoperability between Python style zero-based indexes and PostgreSQL one-based indexes. Pull request courtesy Alexey Terentev.References: #2785
Added the
hashable=False
flag to the PGHSTORE
type, which is needed to allow the ORM to skip over trying to “hash” an ORM-mapped HSTORE column when requesting it in a mixed column/entity list. Patch courtesy Gunnlaugur Þór Briem.This change is also backported to: 0.8.7
References: #3053
Added a new “disconnect” message “connection has been closed unexpectedly”. This appears to be related to newer versions of SSL. Pull request courtesy Antti Haapala.
This change is also backported to: 0.8.7
The psycopg2
.closed
accessor is now consulted when determining if an exception is a “disconnect” error; ideally, this should remove the need for any other inspection of the exception message to detect disconnect, however we will leave those existing messages in place as a fallback. This should be able to handle newer cases like “SSL EOF” conditions. Pull request courtesy Dirk Mueller.References: #3021
Added a new type
OID
to the PostgreSQL dialect. While “oid” is generally a private type within PG that is not exposed in modern versions, there are some PG use cases such as large object support where these types might be exposed, as well as within some user-reported schema reflection use cases.References: #3002
mysql¶
Fixed bug where column names added to
mysql_length
parameter on an index needed to have the same quoting for quoted names in order to be recognized. The fix makes the quotes optional but also provides the old behavior for backwards compatibility with those using the workaround.This change is also backported to: 0.8.7
References: #3085
Added support for reflecting tables where an index includes KEY_BLOCK_SIZE using an equal sign. Pull request courtesy Sean McGivern.
This change is also backported to: 0.8.7
mssql¶
Revised the query used to determine the current default schema name to use the
database_principal_id()
function in conjunction with thesys.database_principals
view so that we can determine the default schema independently of the type of login in progress (e.g., SQL Server, Windows, etc).References: #3025
firebird¶
Fixed bug where the combination of “limit” rendering as “SELECT FIRST n ROWS” using a bound parameter (only firebird has both), combined with column-level subqueries which also feature “limit” as well as “positional” bound parameters (e.g. qmark style) would erroneously assign the subquery-level positions before that of the enclosing SELECT, thus returning parameters which are out of order.
References: #3038
tests¶
Corrected for some deprecation warnings involving the
imp
module and Python 3.3 or greater, when running tests. Pull request courtesy Matt Chisholm.References: #2830
misc¶
The
__mapper_args__
dictionary is copied from a declarative mixin or abstract class when accessed, so that modifications made to this dictionary by declarative itself won’t conflict with that of other mappings. The dictionary is modified regarding theversion_id_col
andpolymorphic_on
arguments, replacing the column within with the one that is officially mapped to the local class/table.This change is also backported to: 0.8.7
References: #3062
Fixed bug in mutable extension where
MutableDict
did not report change events for thesetdefault()
dictionary operation.This change is also backported to: 0.8.7
Fixed bug where
MutableDict.setdefault()
didn’t return the existing or new value (this bug was not released in any 0.8 version). Pull request courtesy Thomas Hervé.This change is also backported to: 0.8.7
In public test suite, changed to use of
String(40)
from less-supportedText
inStringTest.test_literal_backslashes
. Pullreq courtesy Jan.
0.9.4¶
Released: March 28, 2014general¶
Support has been added for pytest to run tests. This runner is currently being supported in addition to nose, and will likely be preferred to nose going forward. The nose plugin system used by SQLAlchemy has been split out so that it works under pytest as well. There are no plans to drop support for nose at the moment and we hope that the test suite itself can continue to remain as agnostic of testing platform as possible. See the file README.unittests.rst for updated information on running tests with pytest.
The test plugin system has also been enhanced to support running tests against multiple database URLs at once, by specifying the
--db
and/or--dburi
flags multiple times. This does not run the entire test suite for each database, but instead allows test cases that are specific to certain backends make use of that backend as the test is run. When using pytest as the test runner, the system will also run specific test suites multiple times, once for each database, particularly those tests within the “dialect suite”. The plan is that the enhanced system will also be used by Alembic, and allow Alembic to run migration operation tests against multiple backends in one run, including third-party backends not included within Alembic itself. Third party dialects and extensions are also encouraged to standardize on SQLAlchemy’s test suite as a basis; see the file README.dialects.rst for background on building out from SQLAlchemy’s test platform.Adjusted
setup.py
file to support the possible future removal of thesetuptools.Feature
extension from setuptools. If this keyword isn’t present, the setup will still succeed with setuptools rather than falling back to distutils. C extension building can be disabled now also by setting the DISABLE_SQLALCHEMY_CEXT environment variable. This variable works whether or not setuptools is even available.This change is also backported to: 0.8.6
References: #2986
Fixed some test/feature failures occurring in Python 3.4, in particular the logic used to wrap “column default” callables wouldn’t work properly for Python built-ins.
References: #2979
orm¶
Added new parameter
mapper.confirm_deleted_rows
. Defaults to True, indicates that a series of DELETE statements should confirm that the cursor rowcount matches the number of primary keys that should have matched; this behavior had been taken off in most cases (except when version_id is used) to support the unusual edge case of self-referential ON DELETE CASCADE; to accommodate this, the message is now just a warning, not an exception, and the flag can be used to indicate a mapping that expects self-referential cascaded deletes of this nature. See also #2403 for background on the original change.References: #3007
A warning is emitted if the
MapperEvents.before_configured()
orMapperEvents.after_configured()
events are applied to a specific mapper or mapped class, as the events are only invoked for theMapper
target at the general level.Added a new keyword argument
once=True
tolisten()
andlistens_for()
. This is a convenience feature which will wrap the given listener such that it is only invoked once.Added a new option to
relationship.innerjoin
which is to specify the string"nested"
. When set to"nested"
as opposed toTrue
, the “chaining” of joins will parenthesize the inner join on the right side of an existing outer join, instead of chaining as a string of outer joins. This possibly should have been the default behavior when 0.9 was released, as we introduced the feature of right-nested joins in the ORM, however we are keeping it as a non-default for now to avoid further surprises.References: #2976
Fixed ORM bug where changing the primary key of an object, then marking it for DELETE would fail to target the correct row for DELETE.
This change is also backported to: 0.8.6
References: #3006
Fixed regression from 0.8.3 as a result of #2818 where
Query.exists()
wouldn’t work on a query that only had aQuery.select_from()
entry but no other entities.This change is also backported to: 0.8.6
References: #2995
Improved an error message which would occur if a query() were made against a non-selectable, such as a
literal_column()
, and then an attempt was made to useQuery.join()
such that the “left” side would be determined asNone
and then fail. This condition is now detected explicitly.This change is also backported to: 0.8.6
Removed stale names from
sqlalchemy.orm.interfaces.__all__
and refreshed with current names, so that animport *
from this module again works.This change is also backported to: 0.8.6
References: #2975
Fixed a very old behavior where the lazy load emitted for a one-to-many could inappropriately pull in the parent table, and also return results inconsistent based on what’s in the parent table, when the primaryjoin includes some kind of discriminator against the parent table, such as
and_(parent.id == child.parent_id, parent.deleted == False)
. While this primaryjoin doesn’t make that much sense for a one-to-many, it is slightly more common when applied to the many-to-one side, and the one-to-many comes as a result of a backref. Loading rows fromchild
in this case would keepparent.deleted == False
as is within the query, thereby yanking it into the FROM clause and doing a cartesian product. The new behavior will now substitute the value of the local “parent.deleted” for that parameter as is appropriate. Though typically, a real-world app probably wants to use a different primaryjoin for the o2m side in any case.References: #2948
Improved the check for “how to join from A to B” such that when a table has multiple, composite foreign keys targeting a parent table, the
relationship.foreign_keys
argument will be properly interpreted in order to resolve the ambiguity; previously this condition would raise that there were multiple FK paths when in fact the foreign_keys argument should be establishing which one is expected.References: #2965
Added support for the not-quite-yet-documented
insert=True
flag forlisten()
to work with mapper / instance events.Fixed bug where events set to listen at the class level (e.g. on the
Mapper
orClassManager
level, as opposed to on an individual mapped class, and also onConnection
) that also made use of internal argument conversion (which is most within those categories) would fail to be removable.References: #2973
Fixed regression from 0.8 where using an option like
lazyload()
with the “wildcard” expression, e.g."*"
, would raise an assertion error in the case where the query didn’t contain any actual entities. This assertion is meant for other cases and was catching this one inadvertently.More fixes to SQLite “join rewriting”; the fix from #2967 implemented right before the release of 0.9.3 affected the case where a UNION contained nested joins in it. “Join rewriting” is a feature with a wide range of possibilities and is the first intricate “SQL rewriting” feature we’ve introduced in years, so we’re sort of going through a lot of iterations with it (not unlike eager loading back in the 0.2/0.3 series, polymorphic loading in 0.4/0.5). We should be there soon so thanks for bearing with us :).
References: #2969
examples¶
Fixed bug in the versioned_history example where column-level INSERT defaults would prevent history values of NULL from being written.
engine¶
Added some new event mechanics for dialect-level events; the initial implementation allows an event handler to redefine the specific mechanics by which an arbitrary dialect invokes execute() or executemany() on a DBAPI cursor. The new events, at this point semi-public and experimental, are in support of some upcoming transaction-related extensions.
An event listener can now be associated with a
Engine
, after one or moreConnection
objects have been created (such as by an ormSession
or via explicit connect) and the listener will pick up events from those connections. Previously, performance concerns pushed the event transfer fromEngine
toConnection
at init-time only, but we’ve inlined a bunch of conditional checks to make this possible without any additional function calls.References: #2978
A major improvement made to the mechanics by which the
Engine
recycles the connection pool when a “disconnect” condition is detected; instead of discarding the pool and explicitly closing out connections, the pool is retained and a “generational” timestamp is updated to reflect the current time, thereby causing all existing connections to be recycled when they are next checked out. This greatly simplifies the recycle process, removes the need for “waking up” connect attempts waiting on the old pool and eliminates the race condition that many immediately-discarded “pool” objects could be created during the recycle operation.References: #2985
The
ConnectionEvents.after_cursor_execute()
event is now emitted for the “_cursor_execute()” method ofConnection
; this is the “quick” executor that is used for things like when a sequence is executed ahead of an INSERT statement, as well as for dialect startup checks like unicode returns, charset, etc. theConnectionEvents.before_cursor_execute()
event was already invoked here. The “executemany” flag is now always set to False here, as this event always corresponds to a single execution. Previously the flag could be True if we were acting on behalf of an executemany INSERT statement.
sql¶
Added support for literal rendering of boolean values, e.g. “true” / “false” or “1” / “0”.
Added a new feature
conv()
, the purpose of which is to mark a constraint name as already having had a naming convention applied. This token will be used by Alembic migrations as of Alembic 0.6.4 in order to render constraints in migration scripts with names marked as already having been subject to a naming convention.The new dialect-level keyword argument system for schema-level constructs has been enhanced in order to assist with existing schemes that rely upon addition of ad-hoc keyword arguments to constructs.
E.g., a construct such as
Index
will again accept ad-hoc keyword arguments within theIndex.kwargs
collection, after construction:idx = Index("a", "b") idx.kwargs["mysql_someargument"] = True
To suit the use case of allowing custom arguments at construction time, the
DialectKWArgs.argument_for()
method now allows this registration:Index.argument_for("mysql", "someargument", False) idx = Index("a", "b", mysql_someargument=True)
See also
DialectKWArgs.argument_for()
Fixed bug in
tuple_()
construct where the “type” of essentially the first SQL expression would be applied as the “comparison type” to a compared tuple value; this has the effect in some cases of an inappropriate “type coercion” occurring, such as when a tuple that has a mix of String and Binary values improperly coerces target values to Binary even though that’s not what they are on the left side.tuple_()
now expects heterogeneous types within its list of values.This change is also backported to: 0.8.6
References: #2977
Fixed an 0.9 regression where a
Table
that failed to reflect correctly wouldn’t be removed from the parentMetaData
, even though in an invalid state. Pullreq courtesy Roman Podoliaka.References: #2988
MetaData.naming_convention
feature will now also apply toCheckConstraint
objects that are associated directly with aColumn
instead of just on theTable
.Fixed bug in new
MetaData.naming_convention
feature where the name of a check constraint making use of the “%(constraint_name)s” token would get doubled up for the constraint generated by a boolean or enum type, and overall duplicate events would cause the “%(constraint_name)s” token to keep compounding itself.References: #2991
Adjusted the logic which applies names to the .c collection when a no-name
BindParameter
is received, e.g. vialiteral()
or similar; the “key” of the bind param is used as the key within .c. rather than the rendered name. Since these binds have “anonymous” names in any case, this allows individual bound parameters to have their own name within a selectable if they are otherwise unlabeled.References: #2974
Some changes to how the
FromClause.c
collection behaves when presented with duplicate columns. The behavior of emitting a warning and replacing the old column with the same name still remains to some degree; the replacement in particular is to maintain backwards compatibility. However, the replaced column still remains associated with thec
collection now in a collection._all_columns
, which is used by constructs such as aliases and unions, to deal with the set of columns inc
more towards what is actually in the list of columns rather than the unique set of key names. This helps with situations where SELECT statements with same-named columns are used in unions and such, so that the union can match the columns up positionally and also there’s some chance ofFromClause.corresponding_column()
still being usable here (it can now return a column that is only in selectable.c._all_columns and not otherwise named). The new collection is underscored as we still need to decide where this list might end up. Theoretically it would become the result of iter(selectable.c), however this would mean that the length of the iteration would no longer match the length of keys(), and that behavior needs to be checked out.References: #2974
Fixed issue in new
TextClause.columns()
method where the ordering of columns given positionally would not be preserved. This could have potential impact in positional situations such as applying the resultingTextAsFrom
object to a union.
postgresql¶
Enabled “sane multi-row count” checking for the psycopg2 DBAPI, as this seems to be supported as of psycopg2 2.0.9.
This change is also backported to: 0.8.6
Fixed regression caused by release 0.8.5 / 0.9.3’s compatibility enhancements where index reflection on PostgreSQL versions specific to only the 8.1, 8.2 series again broke, surrounding the ever problematic int2vector type. While int2vector supports array operations as of 8.1, apparently it only supports CAST to a varchar as of 8.3.
This change is also backported to: 0.8.6
References: #3000
mysql¶
Tweaked the settings for mysql-connector-python; in Py2K, the “supports unicode statements” flag is now False, so that SQLAlchemy will encode the SQL string (note: not the parameters) to bytes before sending to the database. This seems to allow all unicode-related tests to pass for mysql-connector, including those that use non-ascii table/column names, as well as some tests for the TEXT type using unicode under cursor.executemany().
oracle¶
Added a new engine option
coerce_to_unicode=True
to the cx_Oracle dialect, which restores the cx_Oracle outputtypehandler approach to Python unicode conversion under Python 2, which was removed in 0.9.2 as a result of #2911. Some use cases would prefer that unicode coercion is unconditional for all string values, despite performance concerns. Pull request courtesy Christoph Zwerschke.References: #2911
Added new datatype
DATE
, which is a subclass ofDateTime
. As Oracle has no “datetime” type per se, it instead has onlyDATE
, it is appropriate here that theDATE
type as present in the Oracle dialect be an instance ofDateTime
. This issue doesn’t change anything as far as the behavior of the type, as data conversion is handled by the DBAPI in any case, however the improved subclass layout will help the use cases of inspecting types for cross-database compatibility. Also removed uppercaseDATETIME
from the Oracle dialect as this type isn’t functional in that context.References: #2987
tests¶
Fixed a few errant
u''
strings that would prevent tests from passing in Py3.2. Patch courtesy Arfrever Frehtes Taifersar Arahesis.References: #2980
misc¶
Fixed bug in mutable extension as well as
flag_modified()
where the change event would not be propagated if the attribute had been reassigned to itself.This change is also backported to: 0.8.6
References: #2997
Added support to automap for the case where a relationship should not be created between two classes that are in a joined inheritance relationship, for those foreign keys that link the subclass back to the superclass.
References: #3004
Fixed small issue in
SingletonThreadPool
where the current connection to be returned might get inadvertently cleaned out during the “cleanup” process. Patch courtesy jd23.Fixed bug in association proxy where assigning an empty slice (e.g.
x[:] = [...]
) would fail on Py3k.Fixed a regression in association proxy caused by #2810 which caused a user-provided “getter” to no longer receive values of
None
when fetching scalar values from a target that is non-present. The check for None introduced by this change is now moved into the default getter, so a user-provided getter will also again receive values of None.References: #2810
0.9.3¶
Released: February 19, 2014orm¶
Added new
MapperEvents.before_configured()
event which allows an event at the start ofconfigure_mappers()
, as well as__declare_first__()
hook within declarative to complement__declare_last__()
.Fixed bug where
Query.get()
would fail to consistently raise theInvalidRequestError
that invokes when called on a query with existing criterion, when the given identity is already present in the identity map.This change is also backported to: 0.8.5
References: #2951
Fixed bug in SQLite “join rewriting” where usage of an exists() construct would fail to be rewritten properly, such as when the exists is mapped to a column_property in an intricate nested-join scenario. Also fixed a somewhat related issue where join rewriting would fail on the columns clause of the SELECT statement if the targets were aliased tables, as opposed to individual aliased columns.
References: #2967
Fixed an 0.9 regression where ORM instance or mapper events applied to a base class such as a declarative base with the propagate=True flag would fail to apply to existing mapped classes which also used inheritance due to an assertion. Additionally, repaired an attribute error which could occur during removal of such an event, depending on how it was first assigned.
References: #2949
Improved the initialization logic of composite attributes such that calling
MyClass.attribute
will not require that the configure mappers step has occurred, e.g. it will just work without throwing any error.References: #2935
More issues with [ticket:2932] first resolved in 0.9.2 where using a column key of the form
<tablename>_<columnname>
matching that of an aliased column in the text would still not match at the ORM level, which is ultimately due to a core column-matching issue. Additional rules have been added so that the column_label
is taken into account when working with aTextAsFrom
construct or with literal columns.References: #2932
orm declarative¶
Fixed bug where
AbstractConcreteBase
would fail to be fully usable within declarative relationship configuration, as its string classname would not be available in the registry of classnames at mapper configuration time. The class now explicitly adds itself to the class registry, and additionally bothAbstractConcreteBase
as well asConcreteBase
set themselves up before mappers are configured within theconfigure_mappers()
setup, using the newMapperEvents.before_configured()
event.References: #2950
examples¶
Added optional “changed” column to the versioned rows example, as well as support for when the versioned
Table
has an explicitTable.schema
argument. Pull request courtesy jplaverdure.
engine¶
Fixed a critical regression caused by #2880 where the newly concurrent ability to return connections from the pool means that the “first_connect” event is now no longer synchronized either, thus leading to dialect mis-configurations under even minimal concurrency situations.
This change is also backported to: 0.8.5
sql¶
Fixed bug where calling
Insert.values()
with an empty list or tuple would raise an IndexError. It now produces an empty insert construct as would be the case with an empty dictionary.This change is also backported to: 0.8.5
References: #2944
Fixed bug where
ColumnOperators.in_()
would go into an endless loop if erroneously passed a column expression whose comparator included the__getitem__()
method, such as a column that uses theARRAY
type.This change is also backported to: 0.8.5
References: #2957
Fixed regression in new “naming convention” feature where conventions would fail if the referred table in a foreign key contained a schema name. Pull request courtesy Thomas Farvour.
Fixed bug where so-called “literal render” of
bindparam()
constructs would fail if the bind were constructed with a callable, rather than a direct value. This prevented ORM expressions from being rendered with the “literal_binds” compiler flag.
postgresql¶
Added the
TypeEngine.python_type
convenience accessor onto theARRAY
type. Pull request courtesy Alexey Terentev.Added an additional message to psycopg2 disconnect detection, “could not send data to server”, which complements the existing “could not receive data from server” and has been observed by users.
This change is also backported to: 0.8.5
References: #2936
Support has been improved for PostgreSQL reflection behavior on very old (pre 8.1) versions of PostgreSQL, and potentially other PG engines such as Redshift (assuming Redshift reports the version as < 8.1). The query for “indexes” as well as “primary keys” relies upon inspecting a so-called “int2vector” datatype, which refuses to coerce to an array prior to 8.1 causing failures regarding the “ANY()” operator used in the query. Extensive googling has located the very hacky, but recommended-by-PG-core-developer query to use when PG version < 8.1 is in use, so index and primary key constraint reflection now work on these versions.
This change is also backported to: 0.8.5
Revised this very old issue where the PostgreSQL “get primary key” reflection query were updated to take into account primary key constraints that were renamed; the newer query fails on very old versions of PostgreSQL such as version 7, so the old query is restored in those cases when server_version_info < (8, 0) is detected.
This change is also backported to: 0.8.5
References: #2291
Added server version detection to the newly added dialect startup query for “show standard_conforming_strings”; as this variable was added as of PG 8.2, we skip the query for PG versions who report a version string earlier than that.
References: #2946
mysql¶
Added new MySQL-specific
DATETIME
which includes fractional seconds support; also added fractional seconds support toTIMESTAMP
. DBAPI support is limited, though fractional seconds are known to be supported by MySQL Connector/Python. Patch courtesy Geert JM Vanderkelen.This change is also backported to: 0.8.5
References: #2941
Added support for the
PARTITION BY
andPARTITIONS
MySQL table keywords, specified asmysql_partition_by='value'
andmysql_partitions='value'
toTable
. Pull request courtesy Marcus McCurdy.This change is also backported to: 0.8.5
References: #2966
Fixed bug which prevented MySQLdb-based dialects (e.g. pymysql) from working in Py3K, where a check for “connection charset” would fail due to Py3K’s more strict value comparison rules. The call in question wasn’t taking the database version into account in any case as the server version was still None at that point, so the method overall has been simplified to rely upon connection.character_set_name().
This change is also backported to: 0.8.5
References: #2933
Fixed bug in cymysql dialect where a version string such as
'33a-MariaDB'
would fail to parse properly. Pull request courtesy Matt Schmidt.References: #2934
sqlite¶
The SQLite dialect will now skip unsupported arguments when reflecting types; such as if it encounters a string like
INTEGER(5)
, theINTEGER
type will be instantiated without the “5” being included, based on detecting aTypeError
on the first attempt.Support has been added to SQLite type reflection to fully support the “type affinity” contract specified at https://www.sqlite.org/datatype3.html. In this scheme, keywords like
INT
,CHAR
,BLOB
orREAL
located in the type name generically associate the type with one of five affinities. Pull request courtesy Erich Blume.See also
sqlite_type_reflection
misc¶
Fixed bug where the
AutomapBase
class of the new automap extension would fail if classes were pre-arranged in single or potentially joined inheritance patterns. The repaired joined inheritance issue could also potentially apply when usingDeferredReflection
as well.
0.9.2¶
Released: February 2, 2014orm¶
Added a new parameter
Operators.op.is_comparison
. This flag allows a custom op fromOperators.op()
to be considered as a “comparison” operator, thus usable for customrelationship.primaryjoin
conditions.Support is improved for supplying a
join()
construct as the target ofrelationship.secondary
for the purposes of creating very complexrelationship()
join conditions. The change includes adjustments to query joining, joined eager loading to not render a SELECT subquery, changes to lazy loading such that the “secondary” target is properly included in the SELECT, and changes to declarative to better support specification of a join() object with classes as targets.The new use case is somewhat experimental, but a new documentation section has been added.
See also
Fixed error message when an iterator object is passed to
class_mapper()
or similar, where the error would fail to render on string formatting. Pullreq courtesy Kyle Stark.This change is also backported to: 0.8.5
Fixed bug in new
TextAsFrom
construct whereColumn
- oriented row lookups were not matching up to the ad-hocColumnClause
objects thatTextAsFrom
generates, thereby making it not usable as a target inQuery.from_statement()
. Also fixedQuery.from_statement()
mechanics to not mistake aTextAsFrom
for aSelect
construct. This bug is also an 0.9 regression as theTextClause.columns()
method is called to accommodate thetext.typemap
argument.References: #2932
Added a new directive used within the scope of an attribute “set” operation to disable autoflush, in the case that the attribute needs to lazy-load the “old” value, as in when replacing one-to-one values or some kinds of many-to-one. A flush at this point otherwise occurs at the point that the attribute is None and can cause NULL violations.
References: #2921
Fixed an 0.9 regression where the automatic aliasing applied by
Query
and in other situations where selects or joins were aliased (such as joined table inheritance) could fail if a user-definedColumn
subclass were used in the expression. In this case, the subclass would fail to propagate ORM-specific “annotations” along needed by the adaptation. The “expression annotations” system has been corrected to account for this case.References: #2918
Fixed a bug involving the new flattened JOIN structures which are used with
joinedload()
(thereby causing a regression in joined eager loading) as well asaliased()
in conjunction with theflat=True
flag and joined-table inheritance; basically multiple joins across a “parent JOIN sub” entity using different paths to get to a target class wouldn’t form the correct ON conditions. An adjustment / simplification made in the mechanics of figuring out the “left side” of the join in the case of an aliased, joined-inh class repairs the issue.References: #2908
examples¶
Added a tweak to the “history_meta” example where the check for “history” on a relationship-bound attribute will now no longer emit any SQL if the relationship is unloaded.
engine¶
Added a new pool event
PoolEvents.invalidate()
. Called when a DBAPI connection is to be marked as “invalidated” and discarded from the pool.
sql¶
Added
MetaData.reflect.dialect_kwargs
to support dialect-level reflection options for allTable
objects reflected.Added a new feature which allows automated naming conventions to be applied to
Constraint
andIndex
objects. Based on a recipe in the wiki, the new feature uses schema-events to set up names as various schema objects are associated with each other. The events then expose a configuration system through a new argumentMetaData.naming_convention
. This system allows production of both simple and custom naming schemes for constraints and indexes on a per-MetaData
basis.References: #2923
Options can now be specified on a
PrimaryKeyConstraint
object independently of the specification of columns in the table with theprimary_key=True
flag; use aPrimaryKeyConstraint
object with no columns in it to achieve this result.Previously, an explicit
PrimaryKeyConstraint
would have the effect of those columns marked asprimary_key=True
being ignored; since this is no longer the case, thePrimaryKeyConstraint
will now assert that either one style or the other is used to specify the columns, or if both are present, that the column lists match exactly. If an inconsistent set of columns in thePrimaryKeyConstraint
and within theTable
marked asprimary_key=True
are present, a warning is emitted, and the list of columns is taken only from thePrimaryKeyConstraint
alone as was the case in previous releases.See also
PrimaryKeyConstraint
References: #2910
The system by which schema constructs and certain SQL constructs accept dialect-specific keyword arguments has been enhanced. This system includes commonly the
Table
andIndex
constructs, which accept a wide variety of dialect-specific arguments such asmysql_engine
andpostgresql_where
, as well as the constructsPrimaryKeyConstraint
,UniqueConstraint
,Update
,Insert
andDelete
, and also newly added kwarg capability toForeignKeyConstraint
andForeignKey
. The change is that participating dialects can now specify acceptable argument lists for these constructs, allowing an argument error to be raised if an invalid keyword is specified for a particular dialect. If the dialect portion of the keyword is unrecognized, a warning is emitted only; while the system will actually make use of setuptools entrypoints in order to locate non-local dialects, the use case where certain dialect-specific arguments are used in an environment where that third-party dialect is uninstalled remains supported. Dialects also have to explicitly opt-in to this system, so that external dialects which aren’t making use of this system will remain unaffected.References: #2866
The behavior of
Table.tometadata()
has been adjusted such that the schema target of aForeignKey
will not be changed unless that schema matches that of the parent table. That is, if a table “schema_a.user” has a foreign key to “schema_b.order.id”, the “schema_b” target will be maintained whether or not the “schema” argument is passed toTable.tometadata()
. However if a table “schema_a.user” refers to “schema_a.order.id”, the presence of “schema_a” will be updated on both the parent and referred tables. This is a behavioral change hence isn’t likely to be backported to 0.8; it is assumed that the previous behavior is pretty buggy however and that it’s unlikely anyone was relying upon it.Additionally, a new parameter has been added
Table.tometadata.referred_schema_fn
. This refers to a callable function which will be used to determine the new referred schema for anyForeignKeyConstraint
encountered in the tometadata operation. This callable can be used to revert to the previous behavior or to customize how referred schemas are treated on a per-constraint basis.References: #2913
Fixed bug whereby binary type would fail in some cases if used with a “test” dialect, such as a DefaultDialect or other dialect with no DBAPI.
Fixed bug where “literal binds” wouldn’t work with a bound parameter that’s a binary type. A similar, but different, issue is fixed in 0.8.
Fixed regression whereby the “annotation” system used by the ORM was leaking into the names used by standard functions in
sqlalchemy.sql.functions
, such asfunc.coalesce()
andfunc.max()
. Using these functions in ORM attributes and thus producing annotated versions of them could corrupt the actual function name rendered in the SQL.References: #2927
Fixed 0.9 regression where the new sortable support for
RowProxy
would lead toTypeError
when compared to non-tuple types as it attempted to apply tuple() to the “other” object unconditionally. The full range of Python comparison operators have now been implemented onRowProxy
, using an approach that guarantees a comparison system that is equivalent to that of a tuple, and the “other” object is only coerced if it’s an instance of RowProxy.A
UniqueConstraint
created inline with aTable
that has no columns within it will be skipped. Pullreq courtesy Derek Harland.Fixed the multiple-table “UPDATE..FROM” construct, only usable on MySQL, to correctly render the SET clause among multiple columns with the same name across tables. This also changes the name used for the bound parameter in the SET clause to “<tablename>_<colname>” for the non-primary table only; as this parameter is typically specified using the
Column
object directly this should not have an impact on applications. The fix takes effect for bothTable.update()
as well asQuery.update()
in the ORM.References: #2912
schema¶
Restored
sqlalchemy.schema.SchemaVisitor
to the.schema
module. Pullreq courtesy Sean Dague.
postgresql¶
Added a new dialect-level argument
postgresql_ignore_search_path
; this argument is accepted by both theTable
constructor as well as by theMetaData.reflect()
method. When in use against PostgreSQL, a foreign-key referenced table which specifies a remote schema name will retain that schema name even if the name is present in thesearch_path
; the default behavior since 0.7.3 has been that schemas present insearch_path
would not be copied to reflectedForeignKey
objects. The documentation has been updated to describe in detail the behavior of thepg_get_constraintdef()
function and how thepostgresql_ignore_search_path
feature essentially determines if we will honor the schema qualification reported by this function or not.See also
postgresql_schema_reflection
References: #2922
mysql¶
Some missing methods added to the cymysql dialect, including _get_server_version_info() and _detect_charset(). Pullreq courtesy Hajime Nakagami.
This change is also backported to: 0.8.5
Added new test coverage for so-called “down adaptions” of SQL types, where a more specific type is adapted to a more generic one - this use case is needed by some third party tools such as
sqlacodegen
. The specific cases that needed repair within this test suite were that ofENUM
being downcast into aEnum
, and that of SQLite date types being cast into generic date types. Theadapt()
method needed to become more specific here to counteract the removal of a “catch all”**kwargs
collection on the baseTypeEngine
class that was removed in 0.9.References: #2917
The MySQL CAST compilation now takes into account aspects of a string type such as “charset” and “collation”. While MySQL wants all character- based CAST calls to use the CHAR type, we now create a real CHAR object at CAST time and copy over all the parameters it has, so that an expression like
cast(x, mysql.TEXT(charset='utf8'))
will renderCAST(t.col AS CHAR CHARACTER SET utf8)
.Added new “unicode returns” detection to the MySQL dialect and to the default dialect system overall, such that any dialect can add extra “tests” to the on-first-connect “does this DBAPI return unicode directly?” detection. In this case, we are adding a check specifically against the “utf8” encoding with an explicit “utf8_bin” collation type (after checking that this collation is available) to test for some buggy unicode behavior observed with MySQLdb version 1.2.3. While MySQLdb has resolved this issue as of 1.2.4, the check here should guard against regressions. The change also allows the “unicode” checks to log in the engine logs, which was not previously the case.
References: #2906
Connection
now associates a newRootTransaction
orTwoPhaseTransaction
with its immediate_ConnectionFairy
as a “reset handler” for the span of that transaction, which takes over the task of calling commit() or rollback() for the “reset on return” behavior ofPool
if the transaction was not otherwise completed. This resolves the issue that a picky transaction like that of MySQL two-phase will be properly closed out when the connection is closed without an explicit rollback or commit (e.g. no longer raises “XAER_RMFAIL” in this case - note this only shows up in logging as the exception is not propagated within pool reset). This issue would arise e.g. when using an ormSession
withtwophase
set, and thenSession.close()
is called without an explicit rollback or commit. The change also has the effect that you will now see an explicit “ROLLBACK” in the logs when using aSession
object in non-autocommit mode regardless of how that session was discarded. Thanks to Jeff Dairiki and Laurence Rowe for isolating the issue here.References: #2907
sqlite¶
Fixed bug whereby SQLite compiler failed to propagate compiler arguments such as “literal binds” into a CAST expression.
mssql¶
Added an option
mssql_clustered
to theUniqueConstraint
andPrimaryKeyConstraint
constructs; on SQL Server, this adds theCLUSTERED
keyword to the constraint construct within DDL. Pullreq courtesy Derek Harland.
oracle¶
It’s been observed that the usage of a cx_Oracle “outputtypehandler” in Python 2.xx in order to coerce string values to Unicode is inordinately expensive; even though cx_Oracle is written in C, when you pass the Python
unicode
primitive to cursor.var() and associate with an output handler, the library counts every conversion as a Python function call with all the requisite overhead being recorded; this despite the fact when running in Python 3, all strings are also unconditionally coerced to unicode but it does not incur this overhead, meaning that cx_Oracle is failing to use performant techniques in Py2K. As SQLAlchemy cannot easily select for this style of type handler on a per-column basis, the handler was assembled unconditionally thereby adding the overhead to all string access.So this logic has been replaced with SQLAlchemy’s own unicode conversion system, which now only takes effect in Py2K for columns that are requested as unicode. When C extensions are used, SQLAlchemy’s system appears to be 2-3x faster than cx_Oracle’s. Additionally, SQLAlchemy’s unicode conversion has been enhanced such that when the “conditional” converter is required (now needed for the Oracle backend), the check for “already unicode” is now performed in C and no longer introduces significant overhead.
This change has two impacts on the cx_Oracle backend. One is that string values in Py2K which aren’t specifically requested with the Unicode type or convert_unicode=True will now come back as
str
, notunicode
- this behavior is similar to a backend such as MySQL. Additionally, when unicode values are requested with the cx_Oracle backend, if the C extensions are not used, there is now an additional overhead of an isinstance() check per column. This tradeoff has been made as it can be worked around and no longer places a performance burden on the likely majority of Oracle result columns that are non-unicode strings.References: #2911
misc¶
The argument names for the
PoolEvents.reset()
event have been renamed todbapi_connection
andconnection_record
in order to maintain consistency with all the other pool events. It is expected that any existing listeners for this relatively new and seldom-used event are using positional style to receive arguments in any case.Fixed an issue where the C extensions in Py3K are using the wrong API to specify the top-level module function, which breaks in Python 3.4b2. Py3.4b2 changes PyMODINIT_FUNC to return “void” instead of
PyObject *
, so we now make sure to use “PyMODINIT_FUNC” instead ofPyObject *
directly. Pull request courtesy cgohlke.
0.9.1¶
Released: January 5, 2014orm¶
A new, experimental extension
sqlalchemy.ext.automap
is added. This extension expands upon the functionality of Declarative as well as theDeferredReflection
class to produce a base class which automatically generates mapped classes and relationships based on table metadata.Fixed regression where using a
functools.partial()
with the event system would cause a recursion overflow due to usage of inspect.getargspec() on it in order to detect a legacy calling signature for certain events, and apparently there’s no way to do this with a partial object. Instead we skip the legacy check and assume the modern style; the check itself now only occurs for the SessionEvents.after_bulk_update and SessionEvents.after_bulk_delete events. Those two events will require the new signature style if assigned to a “partial” event listener.References: #2905
Fixed bug where using new
Session.info
attribute would fail if the.info
argument were only passed to thesessionmaker
creation call but not to the object itself. Courtesy Robin Schoonover.Fixed regression where we don’t check the given name against the correct string class when setting up a backref based on a name, therefore causing the error “too many values to unpack”. This was related to the Py3k conversion.
References: #2901
Fixed regression where we apparently still create an implicit alias when saying query(B).join(B.cs), where “C” is a joined inh class; however, this implicit alias was created only considering the immediate left side, and not a longer chain of joins along different joined-inh subclasses of the same base. As long as we’re still implicitly aliasing in this case, the behavior is dialed back a bit so that it will alias the right side in a wider variety of cases.
References: #2903
orm declarative¶
Fixed an extremely unlikely memory issue where when using
DeferredReflection
to define classes pending for reflection, if some subset of those classes were discarded before theDeferredReflection.prepare()
method were called to reflect and map the class, a strong reference to the class would remain held within the declarative internals. This internal collection of “classes to map” now uses weak references against the classes themselves.A quasi-regression where apparently in 0.8 you can set a class-level attribute on declarative to simply refer directly to an
InstrumentedAttribute
on a superclass or on the class itself, and it acts more or less like a synonym; in 0.9, this fails to set up enough bookkeeping to keep up with the more liberalized backref logic from #2789. Even though this use case was never directly considered, it is now detected by declarative at the “setattr()” level as well as when setting up a subclass, and the mirrored/renamed attribute is now set up as asynonym()
instead.References: #2900
sql¶
Conjunctions like
and_()
andor_()
can now accept Python generators as a single argument, e.g.:and_(x == y for x, y in tuples)
The logic here looks for a single argument
*args
where the first element is an instance oftypes.GeneratorType
.
schema¶
The
Table.extend_existing
andTable.autoload_replace
parameters are now available on theMetaData.reflect()
method.
0.9.0¶
Released: December 30, 2013orm¶
The
StatementError
or DBAPI-related subclass now can accommodate additional information about the “reason” for the exception; theSession
now adds some detail to it when the exception occurs within an autoflush. This approach is taken as opposed to combiningFlushError
with a Python 3 style “chained exception” approach so as to maintain compatibility both with Py2K code as well as code that already catchesIntegrityError
or similar.Added new argument
include_backrefs=True
to thevalidates()
function; when set to False, a validation event will not be triggered if the event was initiated as a backref to an attribute operation from the other side.References: #1535
A new API for specifying the
FOR UPDATE
clause of aSELECT
is added with the newQuery.with_for_update()
method, to complement the newGenerativeSelect.with_for_update()
method. Pull request courtesy Mario Lassnig.An adjustment to the
subqueryload()
strategy which ensures that the query runs after the loading process has begun; this is so that the subqueryload takes precedence over other loaders that may be hitting the same attribute due to other eager/noload situations at the wrong time.This change is also backported to: 0.8.5
References: #2887
Fixed bug when using joined table inheritance from a table to a select/alias on the base, where the PK columns were also not same named; the persistence system would fail to copy primary key values from the base table to the inherited table upon INSERT.
This change is also backported to: 0.8.5
References: #2885
composite()
will raise an informative error message when the columns/attribute (names) passed don’t resolve to a Column or mapped attribute (such as an erroneous tuple); previously raised an unbound local.This change is also backported to: 0.8.5
References: #2889
Fixed a regression introduced by #2818 where the EXISTS query being generated would produce a “columns being replaced” warning for a statement with two same-named columns, as the internal SELECT wouldn’t have use_labels set.
This change is also backported to: 0.8.4
References: #2818
Added support for the Python 3 method
list.clear()
within the ORM collection instrumentation system; pull request courtesy Eduardo Schettino.Some refinements to the
AliasedClass
construct with regards to descriptors, like hybrids, synonyms, composites, user-defined descriptors, etc. The attribute adaptation which goes on has been made more robust, such that if a descriptor returns another instrumented attribute, rather than a compound SQL expression element, the operation will still proceed. Additionally, the “adapted” operator will retain its class; previously, a change in class fromInstrumentedAttribute
toQueryableAttribute
(a superclass) would interact with Python’s operator system such that an expression likealiased(MyClass.x) > MyClass.x
would reverse itself to readmyclass.x < myclass_1.x
. The adapted attribute will also refer to the newAliasedClass
as its parent which was not always the case before.References: #2872
The
viewonly
flag onrelationship()
will now prevent attribute history from being written on behalf of the target attribute. This has the effect of the object not being written to the Session.dirty list if it is mutated. Previously, the object would be present in Session.dirty, but no change would take place on behalf of the modified attribute during flush. The attribute still emits events such as backref events and user-defined events and will still receive mutations from backrefs.References: #2833
Added support for new
Session.info
attribute toscoped_session
.Fixed bug where usage of new
Bundle
object would cause theQuery.column_descriptions
attribute to fail.Fixed a regression introduced by the join rewriting feature of #2369 and #2587 where a nested join with one side already an aliased select would fail to translate the ON clause on the outside correctly; in the ORM this could be seen when using a SELECT statement as a “secondary” table.
References: #2858
orm declarative¶
Declarative does an extra check to detect if the same
Column
is mapped multiple times under different properties (which typically should be asynonym()
instead) or if two or moreColumn
objects are given the same name, raising a warning if this condition is detected.References: #2828
The
DeferredReflection
class has been enhanced to provide automatic reflection support for the “secondary” table referred to by arelationship()
. “secondary”, when specified either as a string table name, or as aTable
object with only a name andMetaData
object will also be included in the reflection process whenDeferredReflection.prepare()
is called.References: #2865
Fixed bug where in Py2K a unicode literal would not be accepted as the string name of a class or other argument within declarative using
relationship()
.
examples¶
Fixed bug which prevented history_meta recipe from working with joined inheritance schemes more than one level deep.
engine¶
The
engine_from_config()
function has been improved so that we will be able to parse dialect-specific arguments from string configuration dictionaries. Dialect classes can now provide their own list of parameter types and string-conversion routines. The feature is not yet used by the built-in dialects, however.References: #2875
A DBAPI that raises an error on
connect()
which is not a subclass of dbapi.Error (such asTypeError
,NotImplementedError
, etc.) will propagate the exception unchanged. Previously, the error handling specific to theconnect()
routine would both inappropriately run the exception through the dialect’sDialect.is_disconnect()
routine as well as wrap it in asqlalchemy.exc.DBAPIError
. It is now propagated unchanged in the same way as occurs within the execute process.This change is also backported to: 0.8.4
References: #2881
The
QueuePool
has been enhanced to not block new connection attempts when an existing connection attempt is blocking. Previously, the production of new connections was serialized within the block that monitored overflow; the overflow counter is now altered within its own critical section outside of the connection process itself.This change is also backported to: 0.8.4
References: #2880
Made a slight adjustment to the logic which waits for a pooled connection to be available, such that for a connection pool with no timeout specified, it will every half a second break out of the wait to check for the so-called “abort” flag, which allows the waiter to break out in case the whole connection pool was dumped; normally the waiter should break out due to a notify_all() but it’s possible this notify_all() is missed in very slim cases. This is an extension of logic first introduced in 0.8.0, and the issue has only been observed occasionally in stress tests.
This change is also backported to: 0.8.4
References: #2522
Fixed bug where SQL statement would be improperly ASCII-encoded when a pre-DBAPI
StatementError
were raised withinConnection.execute()
, causing encoding errors for non-ASCII statements. The stringification now remains within Python unicode thus avoiding encoding errors.This change is also backported to: 0.8.4
References: #2871
The
create_engine()
routine and the relatedmake_url()
function no longer considers the+
sign to be a space within the password field. The parsing in this area has been adjusted to match more closely to how RFC 1738 handles these tokens, in that bothusername
andpassword
expect only:
,@
, and/
to be encoded.See also
The “password” portion of a create_engine() no longer considers the + sign as an encoded space
References: #2873
The
RowProxy
object is now sortable in Python as a regular tuple is; this is accomplished via ensuring tuple() conversion on both sides within the__eq__()
method as well as the addition of a__lt__()
method.References: #2848
sql¶
New improvements to the
text()
construct, including more flexible ways to set up bound parameters and return types; in particular, atext()
can now be turned into a full FROM-object, embeddable in other statements as an alias or CTE using the new methodTextClause.columns()
. Thetext()
construct can also render “inline” bound parameters when the construct is compiled in a “literal bound” context.See also
A new API for specifying the
FOR UPDATE
clause of aSELECT
is added with the newGenerativeSelect.with_for_update()
method. This method supports a more straightforward system of setting dialect-specific options compared to thefor_update
keyword argument ofselect()
, and also includes support for the SQL standardFOR UPDATE OF
clause. The ORM also includes a new corresponding methodQuery.with_for_update()
. Pull request courtesy Mario Lassnig.The precision used when coercing a returned floating point value to Python
Decimal
via string is now configurable. The flagdecimal_return_scale
is now supported by allNumeric
andFloat
types, which will ensure this many digits are taken from the native floating point value when it is converted to string. If not present, the type will make use of the value of.scale
, if the type supports this setting and it is non-None. Otherwise the original default length of 10 is used.References: #2867
Fixed issue where a primary key column that has a Sequence on it, yet the column is not the “auto increment” column, either because it has a foreign key constraint or
autoincrement=False
set, would attempt to fire the Sequence on INSERT for backends that don’t support sequences, when presented with an INSERT missing the primary key value. This would take place on non-sequence backends like SQLite, MySQL.This change is also backported to: 0.8.5
References: #2896
Fixed bug with
Insert.from_select()
method where the order of the given names would not be taken into account when generating the INSERT statement, thus producing a mismatch versus the column names in the given SELECT statement. Also noted thatInsert.from_select()
implies that Python-side insert defaults cannot be used, since the statement has no VALUES clause.This change is also backported to: 0.8.5
References: #2895
The
cast()
function, when given a plain literal value, will now apply the given type to the given literal value on the bind parameter side according to the type given to the cast, in the same manner as that of thetype_coerce()
function. However unliketype_coerce()
, this only takes effect if a non-clauseelement value is passed tocast()
; an existing typed construct will retain its type.The
ForeignKey
class more aggressively checks the given column argument. If not a string, it checks that the object is at least aColumnClause
, or an object that resolves to one, and that the.table
attribute, if present, refers to aTableClause
or subclass, and not something like anAlias
. Otherwise, aArgumentError
is raised.References: #2883
The precedence rules for the
ColumnOperators.collate()
operator have been modified, such that the COLLATE operator is now of lower precedence than the comparison operators. This has the effect that a COLLATE applied to a comparison will not render parenthesis around the comparison, which is not parsed by backends such as MSSQL. The change is backwards incompatible for those setups that were working around the issue by applyingOperators.collate()
to an individual element of the comparison expression, rather than the comparison expression as a whole.References: #2879
The exception raised when a
BindParameter
is present in a compiled statement without a value now includes the key name of the bound parameter in the error message.This change is also backported to: 0.8.5
schema¶
postgresql¶
Support for PostgreSQL JSON has been added, using the new
JSON
type. Huge thanks to Nathan Rice for implementing and testing this.References: #2581
Added support for PostgreSQL TSVECTOR via the
TSVECTOR
type. Pull request courtesy Noufal Ibrahim.Fixed bug where index reflection would mis-interpret indkey values when using the pypostgresql adapter, which returns these values as lists vs. psycopg2’s return type of string.
This change is also backported to: 0.8.4
References: #2855
Now using psycopg2 UNICODEARRAY extension for handling unicode arrays with psycopg2 + normal “native unicode” mode, in the same way the UNICODE extension is used.
Fixed bug where values within an ENUM weren’t escaped for single quote signs. Note that this is backwards-incompatible for existing workarounds that manually escape the single quotes.
References: #2878
mysql¶
Improvements to the system by which SQL types generate within
__repr__()
, particularly with regards to the MySQL integer/numeric/ character types which feature a wide variety of keyword arguments. The__repr__()
is important for use with Alembic autogenerate for when Python code is rendered in a migration script.References: #2893
mssql¶
The “asdecimal” flag used with the
Float
type will now work with Firebird as well as the mssql+pyodbc dialects; previously the decimal conversion was not occurring.This change is also backported to: 0.8.5
Added “Net-Lib error during Connection reset by peer” message to the list of messages checked for “disconnect” within the pymssql dialect. Courtesy John Anderson.
This change is also backported to: 0.8.5
Fixed bug introduced in 0.8.0 where the
DROP INDEX
statement for an index in MSSQL would render incorrectly if the index were in an alternate schema; the schemaname/tablename would be reversed. The format has been also been revised to match current MSSQL documentation. Courtesy Derek Harland.This change is also backported to: 0.8.4
oracle¶
Added ORA-02396 “maximum idle time” error code to list of “is disconnect” codes with cx_oracle.
This change is also backported to: 0.8.4
References: #2864
Fixed bug where Oracle
VARCHAR
types given with no length (e.g. for aCAST
or similar) would incorrectly renderNone CHAR
or similar.This change is also backported to: 0.8.4
References: #2870
firebird¶
The firebird dialect will quote identifiers which begin with an underscore. Courtesy Treeve Jelbert.
This change is also backported to: 0.8.5
References: #2897
Fixed bug in Firebird index reflection where the columns within the index were not sorted correctly; they are now sorted in order of RDB$FIELD_POSITION.
This change is also backported to: 0.8.5
Changed the queries used by Firebird to list table and view names to query from the
rdb$relations
view instead of therdb$relation_fields
andrdb$view_relations
views. Variants of both the old and new queries are mentioned on many FAQ and blogs, however the new queries are taken straight from the “Firebird FAQ” which appears to be the most official source of info.References: #2898
misc¶
Error message when a string arg sent to
relationship()
which doesn’t resolve to a class or mapper has been corrected to work the same way as when a non-string arg is received, which indicates the name of the relationship which had the configurational error.This change is also backported to: 0.8.5
References: #2888
Fixed bug which prevented the
serializer
extension from working correctly with table or column names that contain non-ASCII characters.This change is also backported to: 0.8.4
References: #2869
The “informix” and “informixdb” dialects have been removed; the code is now available as a separate repository on Bitbucket. The IBM-DB project has provided production-level Informix support since the informixdb dialect was first added.
0.9.0b1¶
Released: October 26, 2013general¶
The C extensions are ported to Python 3 and will build under any supported CPython 2 or 3 environment.
References: #2161
The codebase is now “in-place” for Python 2 and 3, the need to run 2to3 has been removed. Compatibility is now against Python 2.6 on forward.
References: #2671
A large refactoring of packages has reorganized the import structure of many Core modules as well as some aspects of the ORM modules. In particular
sqlalchemy.sql
has been broken out into several more modules than before so that the very large size ofsqlalchemy.sql.expression
is now pared down. The effort has focused on a large reduction in import cycles. Additionally, the system of API functions insqlalchemy.sql.expression
andsqlalchemy.orm
has been reorganized to eliminate redundancy in documentation between the functions vs. the objects they produce.
orm¶
Added new option to
relationship()
distinct_target_key
. This enables the subquery eager loader strategy to apply a DISTINCT to the innermost SELECT subquery, to assist in the case where duplicate rows are generated by the innermost query which corresponds to this relationship (there’s not yet a general solution to the issue of dupe rows within subquery eager loading, however, when joins outside of the innermost subquery produce dupes). When the flag is set toTrue
, the DISTINCT is rendered unconditionally, and when it is set toNone
, DISTINCT is rendered if the innermost relationship targets columns that do not comprise a full primary key. The option defaults to False in 0.8 (e.g. off by default in all cases), None in 0.9 (e.g. automatic by default). Thanks to Alexander Koval for help with this.This change is also backported to: 0.8.3
References: #2836
The association proxy now returns
None
when fetching a scalar attribute off of a scalar relationship, where the scalar relationship itself points toNone
, instead of raising anAttributeError
.References: #2810
Added new method
AttributeState.load_history()
, works likeAttributeState.history
but also fires loader callables.References: #2787
Added a new load option
load_only()
. This allows a series of column names to be specified as loading “only” those attributes, deferring the rest.References: #1418
The system of loader options has been entirely rearchitected to build upon a much more comprehensive base, the
Load
object. This base allows any common loader option likejoinedload()
,defer()
, etc. to be used in a “chained” style for the purpose of specifying options down a path, such asjoinedload("foo").subqueryload("bar")
. The new system supersedes the usage of dot-separated path names, multiple attributes within options, and the usage of_all()
options.References: #1418
The
composite()
construct now maintains the return object when used in a column-orientedQuery
, rather than expanding out into individual columns. This makes use of the newBundle
feature internally. This behavior is backwards incompatible; to select from a composite column which will expand out, useMyClass.some_composite.clauses
.See also
Composite attributes are now returned as their object form when queried on a per-attribute basis
References: #2824
A new construct
Bundle
is added, which allows for specification of groups of column expressions to aQuery
construct. The group of columns are returned as a single tuple by default. The behavior ofBundle
can be overridden however to provide any sort of result processing to the returned row. The behavior ofBundle
is also embedded into composite attributes now when they are used in a column-orientedQuery
.See also
Column Bundles for ORM queries
Composite attributes are now returned as their object form when queried on a per-attribute basis
References: #2824
The
version_id_generator
parameter ofMapper
can now be specified to rely upon server generated version identifiers, using triggers or other database-provided versioning features, or via an optional programmatic value, by settingversion_id_generator=False
. When using a server-generated version identifier, the ORM will use RETURNING when available to immediately load the new version value, else it will emit a second SELECT.References: #2793
The
eager_defaults
flag ofMapper
will now allow the newly generated default values to be fetched using an inline RETURNING clause, rather than a second SELECT statement, for backends that support RETURNING.References: #2793
Added a new attribute
Session.info
toSession
; this is a dictionary where applications can store arbitrary data local to aSession
. The contents ofSession.info
can be also be initialized using theinfo
argument ofSession
orsessionmaker
.Removal of event listeners is now implemented. The feature is provided via the
remove()
function.See also
References: #2268
The mechanism by which attribute events pass along an
AttributeImpl
as an “initiator” token has been changed; the object is now an event-specific object calledEvent
. Additionally, the attribute system no longer halts events based on a matching “initiator” token; this logic has been moved to be specific to ORM backref event handlers, which are the typical source of the re-propagation of an attribute event onto subsequent append/set/remove operations. End user code which emulates the behavior of backrefs must now ensure that recursive event propagation schemes are halted, if the scheme does not use the backref handlers. Using this new system, backref handlers can now perform a “two-hop” operation when an object is appended to a collection, associated with a new many-to-one, de-associated with the previous many-to-one, and then removed from a previous collection. Before this change, the last step of removal from the previous collection would not occur.References: #2789
A major change regarding how the ORM constructs joins where the right side is itself a join or left outer join. The ORM is now configured to allow simple nesting of joins of the form
a JOIN (b JOIN c ON b.id=c.id) ON a.id=b.id
, rather than forcing the right side into aSELECT
subquery. This should allow significant performance improvements on most backends, most particularly MySQL. The one database backend that has for many years held back this change, SQLite, is now addressed by moving the production of theSELECT
subquery from the ORM to the SQL compiler; so that a right-nested join on SQLite will still ultimately render with aSELECT
, while all other backends are no longer impacted by this workaround.As part of this change, a new argument
flat=True
has been added to thealiased()
,Join.alias()
, andwith_polymorphic()
functions, which allows an “alias” of a JOIN to be produced which applies an anonymous alias to each component table within the join, rather than producing a subquery.See also
Many JOIN and LEFT OUTER JOIN expressions will no longer be wrapped in (SELECT * FROM ..) AS ANON_1
References: #2587
Fixed bug where using an annotation such as
remote()
orforeign()
on aColumn
before association with a parentTable
could produce issues related to the parent table not rendering within joins, due to the inherent copy operation performed by an annotation.This change is also backported to: 0.8.3
References: #2813
Fixed bug where
Query.exists()
failed to work correctly without any WHERE criterion. Courtesy Vladimir Magamedov.This change is also backported to: 0.8.3
References: #2818
Fixed a potential issue in an ordered sequence implementation used by the ORM to iterate mapper hierarchies; under the Jython interpreter this implementation wasn’t ordered, even though cPython and PyPy maintained ordering.
This change is also backported to: 0.8.3
References: #2794
Fixed bug in ORM-level event registration where the “raw” or “propagate” flags could potentially be mis-configured in some “unmapped base class” configurations.
This change is also backported to: 0.8.3
References: #2786
A performance fix related to the usage of the
defer()
option when loading mapped entities. The function overhead of applying a per-object deferred callable to an instance at load time was significantly higher than that of just loading the data from the row (note thatdefer()
is meant to reduce DB/network overhead, not necessarily function call count); the function call overhead is now less than that of loading data from the column in all cases. There is also a reduction in the number of “lazy callable” objects created per load from N (total deferred values in the result) to 1 (total number of deferred cols).This change is also backported to: 0.8.3
References: #2778
Fixed bug whereby attribute history functions would fail when an object we moved from “persistent” to “pending” using the
make_transient()
function, for operations involving collection-based backrefs.This change is also backported to: 0.8.3
References: #2773
A warning is emitted when trying to flush an object of an inherited class where the polymorphic discriminator has been assigned to a value that is invalid for the class.
This change is also backported to: 0.8.2
References: #2750
Fixed bug in polymorphic SQL generation where multiple joined-inheritance entities against the same base class joined to each other as well would not track columns on the base table independently of each other if the string of joins were more than two entities long.
This change is also backported to: 0.8.2
References: #2759
Fixed bug where sending a composite attribute into
Query.order_by()
would produce a parenthesized expression not accepted by some databases.This change is also backported to: 0.8.2
References: #2754
Fixed the interaction between composite attributes and the
aliased()
function. Previously, composite attributes wouldn’t work correctly in comparison operations when aliasing was applied.This change is also backported to: 0.8.2
References: #2755
Fixed bug where
MutableDict
didn’t report a change event whenclear()
was called.This change is also backported to: 0.8.2
References: #2730
Fixed bug where list instrumentation would fail to represent a setslice of
[0:0]
correctly, which in particular could occur when usinginsert(0, item)
with the association proxy. Due to some quirk in Python collections, the issue was much more likely with Python 3 rather than 2.This change is also backported to: 0.8.3, 0.8.0b1
References: #2807
get_history()
when used with a scalar column-mapped attribute will now honor the “passive” flag passed to it; as this defaults toPASSIVE_OFF
, the function will by default query the database if the value is not present. This is a behavioral change vs. 0.8.References: #2787
Added additional criterion to the ==, != comparators, used with scalar values, for comparisons to None to also take into account the association record itself being non-present, in addition to the existing test for the scalar endpoint on the association record being NULL. Previously, comparing
Cls.scalar == None
would return records for whichCls.associated
were present andCls.associated.scalar
is None, but not rows for whichCls.associated
is non-present. More significantly, the inverse operationCls.scalar != None
would returnCls
rows for whichCls.associated
was non-present.The case for
Cls.scalar != 'somevalue'
is also modified to act more like a direct SQL comparison; only rows for whichCls.associated
is present andAssociated.scalar
is non-NULL and not equal to'somevalue'
are returned. Previously, this would be a simpleNOT EXISTS
.Also added a special use case where you can call
Cls.scalar.has()
with no arguments, whenCls.scalar
is a column-based value - this returns whether or notCls.associated
has any rows present, regardless of whether or notCls.associated.scalar
is NULL or not.References: #2751
Fixed an obscure bug where the wrong results would be fetched when joining/joinedloading across a many-to-many relationship to a single-table-inheriting subclass with a specific discriminator value, due to “secondary” rows that would come back. The “secondary” and right-side tables are now inner joined inside of parenthesis for all ORM joins on many-to-many relationships so that the left->right join can accurately filtered. This change was made possible by finally addressing the issue with right-nested joins outlined in #2587.
See also
Many JOIN and LEFT OUTER JOIN expressions will no longer be wrapped in (SELECT * FROM ..) AS ANON_1
References: #2369
The “auto-aliasing” behavior of the
Query.select_from()
method has been turned off. The specific behavior is now available via a new methodQuery.select_entity_from()
. The auto-aliasing behavior here was never well documented and is generally not what’s desired, asQuery.select_from()
has become more oriented towards controlling how a JOIN is rendered.Query.select_entity_from()
will also be made available in 0.8 so that applications which rely on the auto-aliasing can shift their applications to use this method.References: #2736
orm declarative¶
Added a convenience class decorator
as_declarative()
, is a wrapper fordeclarative_base()
which allows an existing base class to be applied using a nifty class-decorated approach.This change is also backported to: 0.8.3
ORM descriptors such as hybrid properties can now be referenced by name in a string argument used with
order_by
,primaryjoin
, or similar inrelationship()
, in addition to column-bound attributes.This change is also backported to: 0.8.2
References: #2761
examples¶
Improved the examples in
examples/generic_associations
, including thatdiscriminator_on_association.py
makes use of single table inheritance do the work with the “discriminator”. Also added a true “generic foreign key” example, which works similarly to other popular frameworks in that it uses an open-ended integer to point to any other table, foregoing traditional referential integrity. While we don’t recommend this pattern, information wants to be free.This change is also backported to: 0.8.3
Added “autoincrement=False” to the history table created in the versioning example, as this table shouldn’t have autoinc on it in any case, courtesy Patrick Schmid.
This change is also backported to: 0.8.3
Fixed an issue with the “versioning” recipe whereby a many-to-one reference could produce a meaningless version for the target, even though it was not changed, when backrefs were present. Patch courtesy Matt Chisholm.
This change is also backported to: 0.8.2
engine¶
repr()
for theURL
of anEngine
will now conceal the password using asterisks. Courtesy Gunnlaugur Þór Briem.This change is also backported to: 0.8.3
References: #2821
New events added to
ConnectionEvents
:ConnectionEvents.engine_connect()
ConnectionEvents.set_connection_execution_options()
ConnectionEvents.set_engine_execution_options()
References: #2770
Dialect.initialize() is not called a second time if an
Engine
is recreated, due to a disconnect error. This fixes a particular issue in the Oracle 8 dialect, but in general the dialect.initialize() phase should only be once per dialect.This change is also backported to: 0.8.3
References: #2776
Fixed bug where
QueuePool
would lose the correct checked out count if an existing pooled connection failed to reconnect after an invalidate or recycle event.This change is also backported to: 0.8.3
References: #2772
Fixed bug where the
reset_on_return
argument to variousPool
implementations would not be propagated when the pool was regenerated. Courtesy Eevee.This change is also backported to: 0.8.2
The regexp used by the
make_url()
function now parses ipv6 addresses, e.g. surrounded by brackets.This change is also backported to: 0.8.3, 0.8.0b1
References: #2851
The method signature of
Dialect.reflecttable()
, which in all known cases is provided byDefaultDialect
, has been tightened to expectinclude_columns
andexclude_columns
arguments without any kw option, reducing ambiguity - previouslyexclude_columns
was missing.References: #2748
sql¶
Added support for “unique constraint” reflection, via the
Inspector.get_unique_constraints()
method. Thanks for Roman Podolyaka for the patch.This change is also backported to: 0.8.4
References: #1443
The
update()
,insert()
, anddelete()
constructs will now interpret ORM entities as target tables to be operated upon, e.g.:from sqlalchemy import insert, update, delete ins = insert(SomeMappedClass).values(x=5) del_ = delete(SomeMappedClass).where(SomeMappedClass.id == 5) upd = update(SomeMappedClass).where(SomeMappedClass.id == 5).values(name="ed")
This change is also backported to: 0.8.3
The PostgreSQL and MySQL dialects now support reflection/inspection of foreign key options, including ON UPDATE, ON DELETE. PostgreSQL also reflects MATCH, DEFERRABLE, and INITIALLY. Courtesy ijl.
References: #2183
A
bindparam()
construct with a “null” type (e.g. no type specified) is now copied when used in a typed expression, and the new copy is assigned the actual type of the compared column. Previously, this logic would occur on the givenbindparam()
in place. Additionally, a similar process now occurs forbindparam()
constructs passed toValuesBase.values()
for anInsert
orUpdate
construct, within the compilation phase of the construct.These are both subtle behavioral changes which may impact some usages.
References: #2850
An overhaul of expression handling for special symbols particularly with conjunctions, e.g.
None
null()
true()
false()
, including consistency in rendering NULL in conjunctions, “short-circuiting” ofand_()
andor_()
expressions which contain boolean constants, and rendering of boolean constants and expressions as compared to “1” or “0” for backends that don’t featuretrue
/false
constants.The typing system now handles the task of rendering “literal bind” values, e.g. values that are normally bound parameters but due to context must be rendered as strings, typically within DDL constructs such as CHECK constraints and indexes (note that “literal bind” values become used by DDL as of #2742). A new method
TypeEngine.literal_processor()
serves as the base, andTypeDecorator.process_literal_param()
is added to allow wrapping of a native literal rendering method.References: #2838
The
Table.tometadata()
method now produces copies of allSchemaItem.info
dictionaries from allSchemaItem
objects within the structure including columns, constraints, foreign keys, etc. As these dictionaries are copies, they are independent of the original dictionary. Previously, only the.info
dictionary ofColumn
was transferred within this operation, and it was only linked in place, not copied.References: #2716
The
default
argument ofColumn
now accepts a class or object method as an argument, in addition to a standalone function; will properly detect if the “context” argument is accepted or not.Added new method to the
insert()
constructInsert.from_select()
. Given a list of columns and a selectable, rendersINSERT INTO (table) (columns) SELECT ..
. While this feature is highlighted as part of 0.9 it is also backported to 0.8.3.See also
References: #722
Provided a new attribute for
TypeDecorator
calledTypeDecorator.coerce_to_is_types
, to make it easier to control how comparisons using==
or!=
toNone
and boolean types goes about producing anIS
expression, or a plain equality expression with a bound parameter.A
label()
construct will now render as its name alone in anORDER BY
clause, if that label is also referred to in the columns clause of the select, instead of rewriting the full expression. This gives the database a better chance to optimize the evaluation of the same expression in two different contexts.References: #1068
Fixed bug where
type_coerce()
would not interpret ORM elements with a__clause_element__()
method properly.This change is also backported to: 0.8.3
References: #2849
The
Enum
andBoolean
types now bypass any custom (e.g. TypeDecorator) type in use when producing the CHECK constraint for the “non native” type. This so that the custom type isn’t involved in the expression within the CHECK, since this expression is against the “impl” value and not the “decorated” value.This change is also backported to: 0.8.3
References: #2842
The
.unique
flag onIndex
could be produced asNone
if it was generated from aColumn
that didn’t specifyunique
(where it defaults toNone
). The flag will now always beTrue
orFalse
.This change is also backported to: 0.8.3
References: #2825
Fixed bug in default compiler plus those of postgresql, mysql, and mssql to ensure that any literal SQL expression values are rendered directly as literals, instead of as bound parameters, within a CREATE INDEX statement. This also changes the rendering scheme for other DDL such as constraints.
This change is also backported to: 0.8.3
References: #2742
A
select()
that is made to refer to itself in its FROM clause, typically via in-place mutation, will raise an informative error message rather than causing a recursion overflow.This change is also backported to: 0.8.3
References: #2815
Fixed bug where using the
column_reflect
event to change the.key
of the incomingColumn
would prevent primary key constraints, indexes, and foreign key constraints from being correctly reflected.This change is also backported to: 0.8.3
References: #2811
The
ColumnOperators.notin_()
operator added in 0.8 now properly produces the negation of the expression “IN” returns when used against an empty collection.This change is also backported to: 0.8.3
Fixed bug where the expression system relied upon the
str()
form of a some expressions when referring to the.c
collection on aselect()
construct, but thestr()
form isn’t available since the element relies on dialect-specific compilation constructs, notably the__getitem__()
operator as used with a PostgreSQLARRAY
element. The fix also adds a new exception classUnsupportedCompilationError
which is raised in those cases where a compiler is asked to compile something it doesn’t know how to.This change is also backported to: 0.8.3
References: #2780
Multiple fixes to the correlation behavior of
Select
constructs, first introduced in 0.8.0:To satisfy the use case where FROM entries should be correlated outwards to a SELECT that encloses another, which then encloses this one, correlation now works across multiple levels when explicit correlation is established via
Select.correlate()
, provided that the target select is somewhere along the chain contained by a WHERE/ORDER BY/columns clause, not just nested FROM clauses. This makesSelect.correlate()
act more compatibly to that of 0.7 again while still maintaining the new “smart” correlation.When explicit correlation is not used, the usual “implicit” correlation limits its behavior to just the immediate enclosing SELECT, to maximize compatibility with 0.7 applications, and also prevents correlation across nested FROMs in this case, maintaining compatibility with 0.8.0/0.8.1.
The
Select.correlate_except()
method was not preventing the given FROM clauses from correlation in all cases, and also would cause FROM clauses to be incorrectly omitted entirely (more like what 0.7 would do), this has been fixed.Calling select.correlate_except(None) will enter all FROM clauses into correlation as would be expected.
This change is also backported to: 0.8.2
Fixed bug whereby joining a select() of a table “A” with multiple foreign key paths to a table “B”, to that table “B”, would fail to produce the “ambiguous join condition” error that would be reported if you join table “A” directly to “B”; it would instead produce a join condition with multiple criteria.
This change is also backported to: 0.8.2
References: #2738
Fixed bug whereby using
MetaData.reflect()
across a remote schema as well as a local schema could produce wrong results in the case where both schemas had a table of the same name.This change is also backported to: 0.8.2
References: #2728
Removed the “not implemented”
__iter__()
call from the baseColumnOperators
class, while this was introduced in 0.8.0 to prevent an endless, memory-growing loop when one also implements a__getitem__()
method on a custom operator and then calls erroneouslylist()
on that object, it had the effect of causing column elements to report that they were in fact iterable types which then throw an error when you try to iterate. There’s no real way to have both sides here so we stick with Python best practices. Careful with implementing__getitem__()
on your custom operators!This change is also backported to: 0.8.2
References: #2726
Fixed regression dating back to 0.7.9 whereby the name of a CTE might not be properly quoted if it was referred to in multiple FROM clauses.
This change is also backported to: 0.8.3, 0.8.0b1
References: #2801
Fixed bug in common table expression system where if the CTE were used only as an
alias()
construct, it would not render using the WITH keyword.This change is also backported to: 0.8.3, 0.8.0b1
References: #2783
Fixed bug in
CheckConstraint
DDL where the “quote” flag from aColumn
object would not be propagated.This change is also backported to: 0.8.3, 0.8.0b1
References: #2784
The “name” attribute is set on
Index
before the “attach” events are called, so that attachment events can be used to dynamically generate a name for the index based on the parent table and/or columns.References: #2835
The erroneous kw arg “schema” has been removed from the
ForeignKey
object. this was an accidental commit that did nothing; a warning is raised in 0.8.3 when this kw arg is used.References: #2831
A rework to the way that “quoted” identifiers are handled, in that instead of relying upon various
quote=True
flags being passed around, these flags are converted into rich string objects with quoting information included at the point at which they are passed to common schema constructs likeTable
,Column
, etc. This solves the issue of various methods that don’t correctly honor the “quote” flag such asEngine.has_table()
and related methods. Thequoted_name
object is a string subclass that can also be used explicitly if needed; the object will hold onto the quoting preferences passed and will also bypass the “name normalization” performed by dialects that standardize on uppercase symbols, such as Oracle, Firebird and DB2. The upshot is that the “uppercase” backends can now work with force-quoted names, such as lowercase-quoted names and new reserved words.References: #2812
The resolution of
ForeignKey
objects to their targetColumn
has been reworked to be as immediate as possible, based on the moment that the targetColumn
is associated with the sameMetaData
as thisForeignKey
, rather than waiting for the first time a join is constructed, or similar. This along with other improvements allows earlier detection of some foreign key configuration issues. Also included here is a rework of the type-propagation system, so that it should be reliable now to set the type asNone
on anyColumn
that refers to another viaForeignKey
- the type will be copied from the target column as soon as that other column is associated, and now works for composite foreign keys as well.References: #1765
postgresql¶
Support for PostgreSQL 9.2 range types has been added. Currently, no type translation is provided, so works directly with strings or psycopg2 2.5 range extension types at the moment. Patch courtesy Chris Withers.
This change is also backported to: 0.8.2
Added support for “AUTOCOMMIT” isolation when using the psycopg2 DBAPI. The keyword is available via the
isolation_level
execution option. Patch courtesy Roman Podolyaka.This change is also backported to: 0.8.2
References: #2072
Added support for rendering
SMALLSERIAL
when aSmallInteger
type is used on a primary key autoincrement column, based on server version detection of PostgreSQL version 9.2 or greater.References: #2840
Removed a 128-character truncation from the reflection of the server default for a column; this code was original from PG system views which truncated the string for readability.
This change is also backported to: 0.8.3
References: #2844
Parenthesis will be applied to a compound SQL expression as rendered in the column list of a CREATE INDEX statement.
This change is also backported to: 0.8.3
References: #2742
Fixed bug where PostgreSQL version strings that had a prefix preceding the words “PostgreSQL” or “EnterpriseDB” would not parse. Courtesy Scott Schaefer.
This change is also backported to: 0.8.3
References: #2819
The behavior of
extract()
has been simplified on the PostgreSQL dialect to no longer inject a hardcoded::timestamp
or similar cast into the given expression, as this interfered with types such as timezone-aware datetimes, but also does not appear to be at all necessary with modern versions of psycopg2.This change is also backported to: 0.8.2
References: #2740
Fixed bug in HSTORE type where keys/values that contained backslashed quotes would not be escaped correctly when using the “non native” (i.e. non-psycopg2) means of translating HSTORE data. Patch courtesy Ryan Kelly.
This change is also backported to: 0.8.2
References: #2766
Fixed bug where the order of columns in a multi-column PostgreSQL index would be reflected in the wrong order. Courtesy Roman Podolyaka.
This change is also backported to: 0.8.2
References: #2767
mysql¶
The
mysql_length
parameter used withIndex
can now be passed as a dictionary of column names/lengths, for use with composite indexes. Big thanks to Roman Podolyaka for the patch.This change is also backported to: 0.8.2
References: #2704
The MySQL
SET
type now features the same auto-quoting behavior as that ofENUM
. Quotes are not required when setting up the value, but quotes that are present will be auto-detected along with a warning. This also helps with Alembic where the SET type doesn’t render with quotes.References: #2817
The change in #2721, which is that the
deferrable
keyword ofForeignKeyConstraint
is silently ignored on the MySQL backend, will be reverted as of 0.9; this keyword will now render again, raising errors on MySQL as it is not understood - the same behavior will also apply to theinitially
keyword. In 0.8, the keywords will remain ignored but a warning is emitted. Additionally, thematch
keyword now raises aCompileError
on 0.9 and emits a warning on 0.8; this keyword is not only silently ignored by MySQL but also breaks the ON UPDATE/ON DELETE options.To use a
ForeignKeyConstraint
that does not render or renders differently on MySQL, use a custom compilation option. An example of this usage has been added to the documentation, see mysql_foreign_keys.This change is also backported to: 0.8.3
MySQL-connector dialect now allows options in the create_engine query string to override those defaults set up in the connect, including “buffered” and “raise_on_warnings”.
This change is also backported to: 0.8.3
References: #2515
Fixed bug when using multi-table UPDATE where a supplemental table is a SELECT with its own bound parameters, where the positioning of the bound parameters would be reversed versus the statement itself when using MySQL’s special syntax.
This change is also backported to: 0.8.2
References: #2768
Added another conditional to the
mysql+gaerdbms
dialect to detect so-called “development” mode, where we should use therdbms_mysqldb
DBAPI. Patch courtesy Brett Slatkin.This change is also backported to: 0.8.2
References: #2715
The
deferrable
keyword argument onForeignKey
andForeignKeyConstraint
will not render theDEFERRABLE
keyword on the MySQL dialect. For a long time we left this in place because a non-deferrable foreign key would act very differently than a deferrable one, but some environments just disable FKs on MySQL, so we’ll be less opinionated here.This change is also backported to: 0.8.2
References: #2721
Updates to MySQL reserved words for versions 5.5, 5.6, courtesy Hanno Schlichting.
This change is also backported to: 0.8.3, 0.8.0b1
References: #2791
Fix and test parsing of MySQL foreign key options within reflection; this complements the work in #2183 where we begin to support reflection of foreign key options such as ON UPDATE/ON DELETE cascade.
References: #2839
Improved support for the cymysql driver, supporting version 0.6.5, courtesy Hajime Nakagami.
sqlite¶
The newly added SQLite DATETIME arguments storage_format and regexp apparently were not fully implemented correctly; while the arguments were accepted, in practice they would have no effect; this has been fixed.
This change is also backported to: 0.8.3
References: #2781
Added
sqlalchemy.types.BIGINT
to the list of type names that can be reflected by the SQLite dialect; courtesy Russell Stuart.This change is also backported to: 0.8.2
References: #2764
mssql¶
When querying the information schema on SQL Server 2000, removed a CAST call that was added in 0.8.1 to help with driver issues, which apparently is not compatible on 2000. The CAST remains in place for SQL Server 2005 and greater.
This change is also backported to: 0.8.2
References: #2747
Fixes to MSSQL with Python 3 + pyodbc, including that statements are passed correctly.
References: #2355
oracle¶
The Oracle unit tests with cx_oracle now pass fully under Python 3.
Fixed bug where Oracle table reflection using synonyms would fail if the synonym and the table were in different remote schemas. Patch to fix courtesy Kyle Derr.
This change is also backported to: 0.8.3
References: #2853
firebird¶
Added new flag
retaining=True
to the kinterbasdb and fdb dialects. This controls the value of theretaining
flag sent to thecommit()
androllback()
methods of the DBAPI connection. Due to historical concerns, this flag defaults toTrue
in 0.8.2, however in 0.9.0b1 this flag defaults toFalse
.This change is also backported to: 0.8.2
References: #2763
The
fdb
dialect is now the default dialect when specified without a dialect qualifier, i.e.firebird://
, per the Firebird project publishingfdb
as their official Python driver.References: #2504
Type lookup when reflecting the Firebird types LONG and INT64 has been fixed so that LONG is treated as INTEGER, INT64 treated as BIGINT, unless the type has a “precision” in which case it’s treated as NUMERIC. Patch courtesy Russell Stuart.
This change is also backported to: 0.8.2
References: #2757
misc¶
Added a new flag
system=True
toColumn
, which marks the column as a “system” column which is automatically made present by the database (such as PostgreSQLoid
orxmin
). The column will be omitted from theCREATE TABLE
statement but will otherwise be available for querying. In addition, theCreateColumn
construct can be applied to a custom compilation rule which allows skipping of columns, by producing a rule that returnsNone
.This change is also backported to: 0.8.3
Added a new variant to
UpdateBase.returning()
calledValuesBase.return_defaults()
; this allows arbitrary columns to be added to the RETURNING clause of the statement without interfering with the compilers usual “implicit returning” feature, which is used to efficiently fetch newly generated primary key values. For supporting backends, a dictionary of all fetched values is present atResultProxy.returned_defaults
.References: #2793
Added pool logging for “rollback-on-return” and the less used “commit-on-return”. This is enabled with the rest of pool “debug” logging.
References: #2752
Fixed bug whereby if a composite type were set up with a function instead of a class, the mutable extension would trip up when it tried to check that column for being a
MutableComposite
(which it isn’t). Courtesy asldevi.This change is also backported to: 0.8.2
The Python mock library is now required in order to run the unit test suite. While part of the standard library as of Python 3.3, previous Python installations will need to install this in order to run unit tests or to use the
sqlalchemy.testing
package for external dialects.This change is also backported to: 0.8.2