Very awaited version for me (because the selectin) ! I tested in my code both the eagerload and the polymorphic usages, and everything works perfectly.
Thank you Mike Le lundi 10 juillet 2017 16:44:03 UTC+3, Mike Bayer a écrit : > > SQLAlchemy release 1.2.0b1 is now available. > > This is the first beta for the 1.2 series of SQLAlchemy. As is always > the case for beta releases, the release is available on Pypi, but only > installable when specifying the --pre flag with pip. > > Key highlights of version 1.2 include: > > * Connection pool pre-ping - The connection pool now includes an > optional "pre ping" feature that will test the "liveness" of a pooled > connection for every connection checkout, transparently recycling the > DBAPI connection if the database is disconnected. This feature > eliminates the need for the "pool recycle" flag as well as the issue > of errors raised when a pooled connection is used after a database > restart. > > * New eagerloading features - an all-new eager loader called > "selectin" is added. This loader is similar to "subquery" eager > loading, but foregoes embedding a complex subquery in favor of using a > simple IN expression which uses the primary key values of the > just-loaded objects to locate related rows. This style of loading will > perform dramatically better than "subquery" eager loading in many > cases. > > * New polymorphic loading options - A new "selectin" loader is also > implemented for polymorphic inheritance hierarchies, which will load > the extra table rows for subclasses in a result set all at once, > without the need to use JOIN or "with_polymorphic". New declarative > options are added to allow per-subclass polymorphic loading > configuration as well. > > * The IN operator now emits a simple expression for empty IN - The > long standing behavior of "empty in" resolving to a non-performant > expression with a warning has been removed as default behavior; for an > IN with no elements, a simple 1 != 1 expression is now used to > evaluate to "false". > > * INSERT..ON DUPLICATE KEY UPDATE support in MySQL - complementing the > support for PostgreSQL "INSERT..ON CONFLICT" in 1.1, the MySQL dialect > now supports the ON DUPLICATE KEY phrase. Simple database-agnostic > "merge" routines can now be composed against these two backends. > > * COMMENT Support - thanks to a generous contribution, version 1.2 can > emit all necessary DDL as well as fully reflect SQL comments for > tables and columns against the MySQL, PostgreSQL, and Oracle backends. > > * SQL expression caching within ORM loaders - the "lazyload" feature > as well as the new "selectin" loading now use SQL expression caching > using the "baked query" extension when emitting queries, removing a > significant bulk of Python overhead from these very common operations. > > Users should carefully review the "What's New in SQLAlchemy 1.2? > document" [1] as well as the Changelog [2] to note which behaviors and > issues are affected. We'd like to thank the many contributors who > helped with this release. > > SQLAlchemy 1.2.0b1 is available on the Download Page [3]. > > [1] http://docs.sqlalchemy.org/en/latest/changelog/migration_12.html > [2] http://www.sqlalchemy.org/changelog/CHANGES_1_2_0b1 > [3] http://www.sqlalchemy.org/download.html > -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
