constructs are now importable from the "from sqlalchemy" namespace,
just like every other Core construct.
- The implicit conversion of strings to :func:`.text` constructs
when passed to most builder methods of :func:`.select` as
well as :class:`.Query` now emits a warning with just the
plain string sent. The textual conversion still proceeds normally,
however. The only method that accepts a string without a warning
are the "label reference" methods like order_by(), group_by();
these functions will now at compile time attempt to resolve a single
string argument to a column or label expression present in the
selectable; if none is located, the expression still renders, but
you get the warning again. The rationale here is that the implicit
conversion from string to text is more unexpected than not these days,
and it is better that the user send more direction to the Core / ORM
when passing a raw string as to what direction should be taken.
Core/ORM tutorials have been updated to go more in depth as to how text
is handled.
fixes#2992
:meth:`.Query.select_from` method no longer set up the "from
entity" of the :class:`.Query` object correctly, so that
subsequent :meth:`.Query.filter_by` or :meth:`.Query.join`
calls would fail to check the appropriate "from" entity when
searching for attributes by string name.
fixes#3083
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.
Addtionally, the "adapted" operator will retain its class; previously,
a change in class from ``InstrumentedAttribute`` to ``QueryableAttribute``
(a superclass) would interact with Python's operator system such that
an expression like ``aliased(MyClass.x) > MyClass.x`` would reverse itself
to read ``myclass.x < myclass_1.x``. The adapted attribute will also
refer to the new :class:`.AliasedClass` as its parent which was not
always the case before. [ticket:2872]
- The system of loader options has been entirely rearchitected to build
upon a much more comprehensive base, the :class:`.Load` object. This
base allows any common loader option like :func:`.joinedload`,
:func:`.defer`, etc. to be used in a "chained" style for the purpose
of specifying options down a path, such as ``joinedload("foo").subqueryload("bar")``.
The new system supersedes the usage of dot-separated path names,
multiple attributes within options, and the usage of ``_all()`` options.
- Added a new load option :func:`.orm.load_only`. This allows a series
of column names to be specified as loading "only" those attributes,
deferring the rest.
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.
[ticket:2369]
labeled columns when apply_labels() is used; this mode
produces a SELECT where each column is labeled as in
<tablename>_<columnname>, to remove column name collisions
for a multiple table select. The fix is that if two labels
collide when combined with the table name, i.e.
"foo.bar_id" and "foo_bar.id", anonymous aliasing will be
applied to one of the dupes. This allows the ORM to handle
both columns independently; previously, 0.7
would in some cases silently emit a second SELECT for the
column that was "duped", and in 0.8 an ambiguous column error
would be emitted. The "keys" applied to the .c. collection
of the select() will also be deduped, so that the "column
being replaced" warning will no longer emit for any select()
that specifies use_labels, though the dupe key will be given
an anonymous label which isn't generally user-friendly.
[ticket:2702]
by proxy that of :class:`.orm.Query`, will not
take effect for a SELECT statement that is being
rendered directly in the FROM list of the enclosing
SELECT. Correlation in SQL only applies to column
expressions such as those in the WHERE, ORDER BY,
columns clause. [ticket:2595]
become an externally usable package but still remains within the main sqlalchemy parent package.
in this system, we use kind of an ugly hack to get the noseplugin imported outside of the
"sqlalchemy" package, while still making it available within sqlalchemy for usage by
third party libraries.
- add some failure cases
- [bug] Firebird now uses strict "ansi bind rules"
so that bound parameters don't render in the
columns clause of a statement - they render
literally instead.
- [bug] Support for passing datetime as date when
using the DateTime type with Firebird; other
dialects support this.
can more flexibly be a non-ORM selectable,
such as a subquery. A selectable placed
in select_from() will now be used as the left
side, favored over implicit usage
of a mapped entity.
If the join still fails based on lack of
foreign keys, the error message includes
this detail. Thanks to brianrhude
on IRC for the test case. [ticket:2298]
construct. Allows an aliased() construct
to link the ORM entity to a selectable that contains
aggregates or other derived forms of a particular
attribute, provided the name is the same as that
of the entity mapped column.
with another label in it would produce incorrect
exported columns. Among other things this would
break an ORM column_property() mapping against
another column_property(). [ticket:2167].
Also in 0.6.8
- _Label() is always against a column or selectable. remove
uncovered case of label against something else.
- start taking notes to clean up some of this labeling stuff,
which will be [ticket:2168]
be clearer in its intent.
- Fine tuning of Query clause adaptation when
from_self(), union(), or other "select from
myself" operation, such that plain SQL expression
elements added to filter(), order_by() etc.
which are present in the nested "from myself"
query *will* be adapted in the same way an ORM
expression element will, since these
elements are otherwise not easily accessible.
[ticket:2155]
all referncing tests to not use globals
- tests that deal with pickle specifically load the fixture classes
from test.lib.pickleable, which gets some more classes added
- removed weird sa05 pickling tests that don't matter
access to the cls/self.tables/classes registries
- express orm/_base.py ORMTest in terms of engine/_base.py TablesTest,
factor out common steps into TablesTest, remove AltEngineTest as a
separate class. will further consolidate these base classes
multiple entities will indicate all collections
along that path should load, instead of requiring
distinct contains_eager() calls for each endpoint
(which was never correctly documented).
[ticket:2032]
- The "name" field used in orm.aliased() now renders
in the resulting SQL statement.
Mike Bayer