we're now using; rework them fully so that their behavioral contract
is consistent regarding adapter.traverse() vs. adapter.columns[],
add a full suite of tests including advanced wrapping scenarios
previously only covered by test/orm/test_froms.py and
test/orm/inheritance/test_relationships.py
- identify several cases where label._order_by_label_clause would be
corrupted, e.g. due to adaption or annotation separately
- add full tests for #3148
The "anonymize label" logic is now generalized to ClauseAdapter, and takes
place when the anonymize_labels flag is sent, taking effect for all
.columns lookups as well as within traverse() calls against the label
directly.
- traverse() will also memoize what it gets in columns, so that
calling upon traverse() / .columns against the same Label will
produce the same anonymized label. This is so that AliasedClass
produces the same anonymized label when it is accessed per-column
(e.g. SomeAlias.some_column) as well as when it is applied to a Query,
and within column loader strategies (e.g. query(SomeAlias)); the
former uses traverse() while the latter uses .columns
- AliasedClass now calls onto ColumnAdapter
- Query also makes sure to use that same ColumnAdapter from the AliasedClass
in all cases
- update the logic from 0.9 in #1068 to make use of the same
_label_resolve_dict we use for #2992, simplifying how that works
and adding support for new scenarios that were pretty broken
(see #3148, #3188)
in 🎫`2682` disallowed the MySQL dialect from making use of the
"true" and "false" symbols in the context of "IS" / "IS NOT", but
MySQL supports this syntax even though it has no boolean type.
MySQL remains "non native boolean", but the :func:`.true`
and :func:`.false` symbols again produce the
keywords "true" and "false", so that an expression like
``column.is_(true())`` again works on MySQL.
fixes#3186
pyodbc will no longer specify a default "driver name", and a warning
is emitted if this is missing. The optimal driver name for SQL Server
changes frequently and is per-platform, so hostname based connections
need to specify this. DSN-based connections are preferred.
fixes#3182
reports a column that isn't found to be present in the table,
a warning is emitted and the column is skipped. This can occur
for some special system column situations as has been observed
with Oracle. fixes#3180
stringify a _label_reference() as is.
- add .key to _label_reference(), so that when _make_proxy()
is called, we don't call str() on it anyway.
- add a test to exercise Query's behavior of adding all the order_by
expressions to the columns list of the select, assert that things
work out when we have a _label_reference there, that it gets sucked
into the columns list and spit out on the other side, it's referred
to appropriately, etc. _label_reference() could theoretically
be resolved at the point we iterate _raw_columns() but
it's better to just let things work as they already do (except
nicer, since we get "tablename.colname" instead of just "somename"
in the columns list) so that we aren't adding a ton of overhead
to _columns_plus_names in the common case.
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
N occurrences of a parameterized string. This allows parameterized
warnings that can refer to their arguments to be delivered a fixed
number of times until allowing Python warning filters to squelch them,
and prevents memory from growing unbounded within Python's
warning registries.
fixes#3178
- an existing state shouldn't need its load_options/load_path updated;
it should maintain those from its original Query source. there's no
tests that check this behavior
instances(), using a named tuple it can assign to directly. this way
we never have to worry about that structure changing anymore, though
we are still having it append (key, fn) which is kind of awkward.
- inline _populators() into instance(), it's a little verbose but
saves an fn call
Mike Bayer