This should hopefully be the last of the beta releases before 0.4.0 is released. The big change in this one is that the ORM Session is now *weak referencing* by default, with an option to turn on the old "strong referencing" behavior. This means that objects in the session get cleared out automatically when they fall out of scope within your application. Objects which have pending changes on them will not get cleared until the session is flushed.
Theres also some refinements to how mappers compile, and it should be much less likely that you'd get stuck with an uncompiled mapper. When defining mappers in an inheritance relationship, the superclass mapper needs to be defined before the corresponding subclass mappers (which should be how everyone is doing it anyway...I think). Other than that you can still define mappers in whatever order regardless of relations to each other. Besides those, we have a lot of bug fixes and some more enhancements and speed improvements. We mainly want to see that this one is stable, works in everyone's environment as well or better than all the other betas, and then we should be ready to go. Download 0.4 beta6 at: http://www.sqlalchemy.org/download.html changelog (also at http://www.sqlalchemy.org/CHANGES) : 0.4.0beta6 ---------- - The Session identity map is now *weak referencing* by default, use weak_identity_map=False to use a regular dict. The weak dict we are using is customized to detect instances which are "dirty" and maintain a temporary strong reference to those instances until changes are flushed. - Mapper compilation has been reorganized such that most compilation occurs upon mapper construction. This allows us to have fewer calls to mapper.compile() and also to allow class-based properties to force a compilation (i.e. User.addresses == 7 will compile all mappers; this is [ticket:758]). The only caveat here is that an inheriting mapper now looks for its inherited mapper upon construction; so mappers within inheritance relationships need to be constructed in inheritance order (which should be the normal case anyway). - added "FETCH" to the keywords detected by Postgres to indicate a result-row holding statement (i.e. in addition to "SELECT"). - Added full list of SQLite reserved keywords so that they get escaped properly. - Tightened up the relationship between the Query's generation of "eager load" aliases, and Query.instances() which actually grabs the eagerly loaded rows. If the aliases were not specifically generated for that statement by EagerLoader, the EagerLoader will not take effect when the rows are fetched. This prevents columns from being grabbed accidentally as being part of an eager load when they were not meant for such, which can happen with textual SQL as well as some inheritance situations. It's particularly important since the "anonymous aliasing" of columns uses simple integer counts now to generate labels. - Removed "parameters" argument from clauseelement.compile(), replaced with "column_keys". The parameters sent to execute() only interact with the insert/update statement compilation process in terms of the column names present but not the values for those columns. Produces more consistent execute/executemany behavior, simplifies things a bit internally. - Added 'comparator' keyword argument to PickleType. By default, "mutable" PickleType does a "deep compare" of objects using their dumps() representation. But this doesn't work for dictionaries. Pickled objects which provide an adequate __eq__() implementation can be set up with "PickleType(comparator=operator.eq)" [ticket:560] - Added session.is_modified(obj) method; performs the same "history" comparison operation as occurs within a flush operation; setting include_collections=False gives the same result as is used when the flush determines whether or not to issue an UPDATE for the instance's row. - Added "schema" argument to Sequence; use this with Postgres /Oracle when the sequence is located in an alternate schema. Implements part of [ticket:584], should fix [ticket:761]. - Fixed reflection of the empty string for mysql enums. - Changed MySQL dialect to use the older LIMIT <offset>, <limit> syntax instead of LIMIT <l> OFFSET <o> for folks using 3.23. [ticket:794] - Added 'passive_deletes="all"' flag to relation(), disables all nulling-out of foreign key attributes during a flush where the parent object is deleted. - Column defaults and onupdates, executing inline, will add parenthesis for subqueries and other parenthesis-requiring expressions - The behavior of String/Unicode types regarding that they auto- convert to TEXT/CLOB when no length is present now occurs *only* for an exact type of String or Unicode with no arguments. If you use VARCHAR or NCHAR (subclasses of String/Unicode) with no length, they will be interpreted by the dialect as VARCHAR/NCHAR; no "magic" conversion happens there. This is less surprising behavior and in particular this helps Oracle keep string-based bind parameters as VARCHARs and not CLOBs [ticket:793]. - Fixes to ShardedSession to work with deferred columns [ticket:771]. - User-defined shard_chooser() function must accept "clause=None" argument; this is the ClauseElement passed to session.execute(statement) and can be used to determine correct shard id (since execute() doesn't take an instance.) - Adjusted operator precedence of NOT to match '==' and others, so that ~(x <operator> y) produces NOT (x <op> y), which is better compatible with older MySQL versions. [ticket:764]. This doesn't apply to "~ (x==y)" as it does in 0.3 since ~(x==y) compiles to "x != y", but still applies to operators like BETWEEN. - Other tickets: [ticket:768], [ticket:728], [ticket:779], [ticket:757] --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. 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