sqlalchemy / CHANGES

Full commit
- completed "post_update" feature, will add a second update statement before inserts
and after deletes in order to reconcile a relationship without any dependencies
being created; used when persisting two rows that are dependent on each other
- completed mapper.using(session) function, localized per-object Session functionality;
objects can be declared and manipulated as local to any user-defined Session
- fix to Oracle "row_number over" clause with multiple tables
- mapper.get() was not selecting multiple-keyed objects if the mapper's table was a join,
such as in an inheritance relationship, this is fixed.
- overhaul to sql/schema packages so that the sql package can run all on its own,
producing selects, inserts, etc. without any engine dependencies.  builds upon
new TableClause/ColumnClause lexical objects.  Schema's Table/Column objects
are the "physical" subclasses of them.  simplifies schema/sql relationship,
extensions (like proxyengine), and speeds overall performance by a large margin. 
removes the entire getattr() behavior that plagued 0.1.1.
- refactoring of how the mapper "synchronizes" data between two objects into a
separate module, works better with properties attached to a mapper that has an 
additional inheritance relationship to one of the related tables, also the same
methodology used to synchronize parent/child objects now used by mapper to
synchronize between inherited and inheriting mappers.
- made objectstore "check for out-of-identitymap" more aggressive, will perform the
check when object attributes are modified or the object is deleted
- Index object fully implemented, can be constructed standalone, or via
"index" and "unique" arguments on Columns.
- added "convert_unicode" flag to SQLEngine, will treat all String/CHAR types
as Unicode types, with raw-byte/utf-8 translation on the bind parameter and 
result set side.
- postgres maintains a list of ANSI functions that must have no parenthesis so
function calls with no arguments work consistently
- tables can be created with no engine specified.  this will default their engine
to a module-scoped "default engine" which is a ProxyEngine.  this engine can 
be connected via the function "global_connect".
- added "refresh(*obj)" method to objectstore / Session to reload the attributes of
any set of objects from the database unconditionally
- fixed a recursive call in schema that was somehow running 994 times then returning
normally.  broke nothing, slowed down everything.  thanks to jpellerin for finding this.

- small fix to Function class so that expressions with a use the type of the
Function object (i.e. the left side) as the type of the boolean expression, not the 
other side which is more of a moving target (changeset 1020).
- creating self-referring mappers with backrefs slightly easier (but still not that easy -
changeset 1019)
- fixes to one-to-one mappings (changeset 1015)
- psycopg1 date/time issue with None fixed (changeset 1005)
- two issues related to postgres, which doesnt want to give you the "lastrowid"
since oids are deprecated:
   * postgres database-side defaults that are on primary key cols *do* execute 
explicitly beforehand, even though thats not the idea of a PassiveDefault.  this is
because sequences on columns get reflected as PassiveDefaults, but need to be explicitly
executed on a primary key col so we know what we just inserted.  
   * if you did add a row that has a bunch of database-side defaults on it, 
and the PassiveDefault thing was working the old way, i.e. they just execute on 
the DB side, the "cant get the row back without an OID" exception that occurred
also will not happen unless someone (usually the ORM) explicitly asks for it.
- fixed a glitch with engine.execute_compiled where it was making a second 
ResultProxy that just got thrown away.
- began to implement newer logic in object properities.  you can now say, which will give you the PropertyLoader corresponding to that
attribute, i.e. myclass.mapper.props['attr']
- eager loading has been internally overhauled to use aliases at all times.  more 
complicated chains of eager loads can now be created without any need for explicit
"use aliases"-type instructions.  EagerLoader code is also much simpler now.
- a new somewhat experimental flag "use_update" added to relations, indicates that 
this relationship should be handled by a second UPDATE statement, either after a 
primary INSERT or before a primary DELETE.  handles circular row dependencies.
- added exceptions module, all raised exceptions (except for some 
KeyError/AttributeError exceptions) descend from these classes.
- fix to date types with MySQL, returned timedelta converted to datetime.time
- two-phase objectstore.commit operations (i.e. begin/commit) now return a 
transactional object (SessionTrans), to more clearly indicate transaction boundaries.
- Index object with create/drop support added to schema
- fix to postgres, where it will explicitly pre-execute a PassiveDefault on a table
if it is a primary key column, pursuant to the ongoing "we cant get inserted rows 
back from postgres" issue
- change to information_schema query that gets back postgres table defs, now
uses explicit JOIN keyword, since one user had faster performance with 8.1
- fix to engine.process_defaults so it works correctly with a table that has 
different column name/column keys (changset 982)
- a column can only be attached to one table - this is now asserted
- postgres time types descend from Time type
- fix to alltests so that it runs types test (now named testtypes)
- fix to Join object so that it correctly exports its foreign keys (cs 973)
- creating relationships against mappers that use inheritance fixed (cs 973)

initial release