Log Message:
py-sqlalchemy: updated to 1.3.7

1.3.7

Released: August 14, 2019
orm

[orm] [bug]
Fixed regression caused by new selectinload for many-to-one logic where a \ 
primaryjoin condition not based on real foreign keys would cause KeyError if a \ 
related object did not exist for a given key value on the parent object.

[orm] [bug]
Fixed bug where using Query.first() or a slice expression in conjunction with a \ 
query that has an expression based “offset” applied would raise TypeError, \ 
due to an “or” conditional against “offset” that did not expect it to be \ 
a SQL expression as opposed to an integer or None.

sql

[sql] [bug]
Fixed issue where Index object which contained a mixture of functional \ 
expressions which were not resolvable to a particular column, in combination \ 
with string-based column names, would fail to initialize its internal state \ 
correctly leading to failures during DDL compilation.

[sql] [bug]
Fixed bug where TypeEngine.column_expression() method would not be applied to \ 
subsequent SELECT statements inside of a UNION or other CompoundSelect, even \ 
though the SELECT statements are rendered at the topmost level of the statement. \ 
New logic now differentiates between rendering the column expression, which is \ 
needed for all SELECTs in the list, vs. gathering the returned data type for the \ 
result row, which is needed only for the first SELECT.

[sql] [bug]
Fixed issue where internal cloning of SELECT constructs could lead to a key \ 
error if the copy of the SELECT changed its state such that its list of columns \ 
changed. This was observed to be occurring in some ORM scenarios which may be \ 
unique to 1.3 and above, so is partially a regression fix.

postgresql

[postgresql] [usecase]
Added new dialect flag for the psycopg2 dialect, executemany_mode which \ 
supersedes the previous experimental use_batch_mode flag. executemany_mode \ 
supports both the “execute batch” and “execute values” functions \ 
provided by psycopg2, the latter which is used for compiled insert() constructs. \ 
Pull request courtesy Yuval Dinari.
See also
Psycopg2 Fast Execution Helpers

mysql

[mysql] [bug]
The MySQL dialects will emit “SET NAMES” at the start of a connection when \ 
charset is given to the MySQL driver, to appease an apparent behavior observed \ 
in MySQL 8.0 that raises a collation error when a UNION includes string columns \ 
unioned against columns of the form CAST(NULL AS CHAR(..)), which is what \ 
SQLAlchemy’s polymorphic_union function does. The issue seems to have affected \ 
PyMySQL for at least a year, however has recently appeared as of mysqlclient \ 
1.4.4 based on changes in how this DBAPI creates a connection. As the presence \ 
of this directive impacts three separate MySQL charset settings which each have \ 
intricate effects based on their presense, SQLAlchemy will now emit the \ 
directive on new connections to ensure correct behavior.

[mysql] [bug]
Added another fix for an upstream MySQL 8 issue where a case sensitive table \ 
name is reported incorrectly in foreign key constraint reflection, this is an \ 
extension of the fix first added for 4344 which affects a case sensitive column \ 
name. The new issue occurs through MySQL 8.0.17, so the general logic of the \ 
88718 fix remains in place.
See also
https://bugs.mysql.com/bug.php?id=96365 - upstream bug

[mysql] [usecase]
Added reserved words ARRAY and MEMBER to the MySQL reserved words list, as MySQL \ 
8.0 has now made these reserved.

sqlite

[sqlite] [bug]
The dialects that support json are supposed to take arguments json_serializer \ 
and json_deserializer at the create_engine() level, however the SQLite dialect \ 
calls them _json_serilizer and _json_deserilalizer. The names have been \ 
corrected, the old names are accepted with a change warning, and these \ 
parameters are now documented as create_engine.json_serializer and \ 
create_engine.json_deserializer.

[sqlite] [bug]
Fixed bug where usage of “PRAGMA table_info” in SQLite dialect meant that \ 
reflection features to detect for table existence, list of table columns, and \ 
list of foreign keys, would default to any table in any attached database, when \ 
no schema name was given and the table did not exist in the base schema. The fix \ 
explicitly runs PRAGMA for the ‘main’ schema and then the ‘temp’ schema \ 
if the ‘main’ returned no rows, to maintain the behavior of tables + temp \ 
tables in the “no schema” namespace, attached tables only in the \ 
“schema” namespace.

mssql

[mssql] [usecase]
Added new mssql.try_cast() construct for SQL Server which emits “TRY_CAST” \ 
syntax. Pull request courtesy Leonel Atencio.

misc

[bug] [events]
Fixed issue in event system where using the once=True flag with dynamically \ 
generated listener functions would cause event registration of future events to \ 
fail if those listener functions were garbage collected after they were used, \ 
due to an assumption that a listened function is strongly referenced. The \ 
“once” wrapped is now modified to strongly reference the inner function \ 
persistently, and documentation is updated that using “once” does not imply \ 
automatic de-registration of listener functions.

1.3.6

orm

[orm] [feature]
Added new loader option method Load.options() which allows loader options to be \ 
constructed hierarchically, so that many sub-options can be applied to a \ 
particular path without needing to call defaultload() many times. Thanks to \ 
Alessio Bogon for the idea.

[orm] [bug]
Fixed regression caused by 4365 where a join from an entity to itself without \ 
using aliases no longer raises an informative error message, instead failing on \ 
an assertion. The informative error condition has been restored.

[orm] [bug]
Fixed an issue where the orm._ORMJoin.join() method, which is a \ 
not-internally-used ORM-level method that exposes what is normally an internal \ 
process of Query.join(), did not propagate the full and outerjoin keyword \ 
arguments correctly. Pull request courtesy Denis Kataev.

[orm] [bug]
Fixed bug where a many-to-one relationship that specified uselist=True would \ 
fail to update correctly during a primary key change where a related column \ 
needs to change.

[orm] [bug]
Fixed bug where the detection for many-to-one or one-to-one use with a \ 
“dynamic” relationship, which is an invalid configuration, would fail to \ 
raise if the relationship were configured with uselist=True. The current fix is \ 
that it warns, instead of raises, as this would otherwise be backwards \ 
incompatible, however in a future release it will be a raise.

[orm] [bug]
Fixed bug where a synonym created against a mapped attribute that does not exist \ 
yet, as is the case when it refers to backref before mappers are configured, \ 
would raise recursion errors when trying to test for attributes on it which \ 
ultimately don’t exist (as occurs when the classes are run through Sphinx \ 
autodoc), as the unconfigured state of the synonym would put it into an \ 
attribute not found loop.

[orm] [performance]
The optimization applied to selectin loading in 4340 where a JOIN is not needed \ 
to eagerly load related items is now applied to many-to-one relationships as \ 
well, so that only the related table is queried for a simple join condition. In \ 
this case, the related items are queried based on the value of a foreign key \ 
column on the parent; if these columns are deferred or otherwise not loaded on \ 
any of the parent objects in the collection, the loader falls back to the JOIN \ 
method.

engine

[engine] [bug]
Fixed bug where using reflection function such as MetaData.reflect() with an \ 
Engine object that had execution options applied to it would fail, as the \ 
resulting OptionEngine proxy object failed to include a .engine attribute used \ 
within the reflection routines.

sql

[sql] [bug]
Adjusted the initialization for Enum to minimize how often it invokes the \ 
.__members__ attribute of a given PEP-435 enumeration object, to suit the case \ 
where this attribute is expensive to invoke, as is the case for some popular \ 
third party enumeration libraries.

[sql] [bug] [postgresql]
oduce the correct operator precedence in combination with the array index operator.

[sql] [bug]
Fixed an unlikely issue where the “corresponding column” routine for unions \ 
and other CompoundSelect objects could return the wrong column in some \ 
overlapping column situtations, thus potentially impacting some ORM operations \ 
when set operations are in use, if the underlying select() constructs were used \ 
previously in other similar kinds of routines, due to a cached value not being \ 
cleared.

postgresql

[postgresql] [usecase]
Added support for reflection of indexes on PostgreSQL partitioned tables, which \ 
was added to PostgreSQL as of version 11.

[postgresql] [usecase]
Added support for multidimensional Postgresql array literals via nesting the \ 
postgresql.array object within another one. The multidimensional array type is \ 
detected automatically.
See also
postgresql.array

mysql

[mysql] [bug]
Fixed bug where the special logic to render “NULL” for the TIMESTAMP \ 
datatype when nullable=True would not work if the column’s datatype were a \ 
TypeDecorator or a Variant. The logic now ensures that it unwraps down to the \ 
original TIMESTAMP so that this special case NULL keyword is correctly rendered \ 
when requested.

[mysql] [bug]
Enhanced MySQL/MariaDB version string parsing to accommodate for exotic MariaDB \ 
version strings where the “MariaDB” word is embedded among other \ 
alphanumeric characters such as “MariaDBV1”. This detection is critical in \ 
order to correctly accommodate for API features that have split between MySQL \ 
and MariaDB such as the “transaction_isolation” system variable.

sqlite

[sqlite] [usecase]
Added support for composite (tuple) IN operators with SQLite, by rendering the \ 
VALUES keyword for this backend. As other backends such as DB2 are known to use \ 
the same syntax, the syntax is enabled in the base compiler using a \ 
dialect-level flag tuple_in_values. The change also includes support for \ 
“empty IN tuple” expressions for SQLite when using “in_()” between a \ 
tuple value and an empty set.

mssql

[mssql] [bug]
Ensured that the queries used to reflect indexes and view definitions will \ 
explicitly CAST string parameters into NVARCHAR, as many SQL Server drivers \ 
frequently treat string values, particularly those with non-ascii characters or \ 
larger string values, as TEXT which often don’t compare correctly against \ 
VARCHAR characters in SQL Server’s information schema tables for some reason. \ 
These CAST operations already take place for reflection queries against SQL \ 
Server information_schema. tables but were missing from three additional queries \ 
that are against sys. tables.