Targeting select / insert / update / delete, the goal
is to minimize overhead of construction and generative methods
so that only the raw arguments passed are handled. An interim
stage that converts the raw state into more compiler-ready state
is added, which is analogous to the ORM QueryContext which will
also be rolled in to be a similar concept, as is currently
being prototyped in I19e05b3424b07114cce6c439b05198ac47f7ac10.
the ORM update/delete BulkUD concept is also going to be rolled
onto this idea. So while the compiler-ready state object,
here called DMLState, looks a little thin, it's the
base of a bigger pattern that will allow for ORM functionality
to embed itself directly into the compiler, execution
context, and result set objects.
This change targets the DML objects, primarily focused on the
values() method which is the most complex process. The
work done by values() is minimized as much as possible
while still being able to create a cache key. Additional
computation is then offloaded to a new object ValuesState
that is handled by the compiler.
Architecturally, a big change here is that insert.values()
and update.values() will generate BindParameter objects for
the values now, which are then carefully received by crud.py
so that they generate the expected names. This is so that
the values() portion of these constructs is cacheable.
for the "multi-values" version of Insert, this is all skipped
and the plan right now is that a multi-values insert is
not worth caching (can always be revisited).
Using the
coercions system in values() also gets us nicer validation
for free, we can remove the NotAClauseElement thing from
schema, and we also now require scalar_subquery() is called
for an insert/update that uses a SELECT as a column value,
1.x deprecation path is added.
The traversal system is then applied to the DML objects
including tests so that they have traversal, cloning, and
cache key support. cloning is not a use case for DML however
having it present allows better validation of the structure
within the tests.
Special per-dialect DML is explicitly not cacheable at the moment,
more as a proof of concept that third party DML constructs can
exist as gracefully not-cacheable rather than producing an
incomplete cache key.
A few selected performance improvements have been added as well,
simplifying the immutabledict.union() method and adding
a new SQLCompiler function that can generate delimeter-separated
clauses like WHERE and ORDER BY without having to build
a ClauseList object at all. The use of ClauseList will
be removed from Select in an upcoming commit. Overall,
ClaustList is unnecessary for internal use and only adds
overhead to statement construction and will likely be removed
as much as possible except for explcit use of conjunctions like
and_() and or_().
Change-Id: I408e0b8be91fddd77cf279da97f55020871f75a9
In 9fca5d827d we attempted to deprecate the "inline=True" flag
and add a generative inline() method, however failed to include
any tests and the method was implemented incorrectly such that
it would get overwritten with the boolean flag immediately.
Rename the internal "inline" flag to "_inline" and add test
support both for the method as well as deprecated support
for the flag, including a fixture addition to assert the expected
value of the flag as it generally does not affect the
actual compiled SQL string.
Change-Id: I0450049f17f1f0d91e22d27f1a973a2b6c0e59f7
Reorganization of Select() is the first major element
of the 2.0 restructuring. In order to start this we need
to first create the new Select constructor and apply legacy
elements to the old one. This in turn necessitates
starting up the RemovedIn20Warning concept which itself
need to refer to "sqlalchemy.future", so begin to establish
this basic framework. Additionally, update the
DML constructors with the newer no-keyword style. Remove
the use of the "pending deprecation" and fix Query.add_column()
deprecation which was not acting as deprecated.
Fixes: #4845Fixes: #4648
Change-Id: I0c7a22b2841a985e1c379a0bb6c94089aae6264c
Creating an :func:`.and_` or :func:`.or_` construct with no arguments or
empty ``*args`` will now emit a deprecation warning, as the SQL produced is
a no-op (i.e. it renders as a blank string). This behavior is considered to
be non-intuitive, so for empty or possibly empty :func:`.and_` or
:func:`.or_` constructs, an appropriate default boolean should be included,
such as ``and_(True, *args)`` or ``or_(False, *args)``. As has been the
case for many major versions of SQLAlchemy, these particular boolean
values will not render if the ``*args`` portion is non-empty.
As there are some internal cases where an empty and_() construct is used
in order to build an optional WHERE expression, a private
utility function is added to suit this use case.
Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Fixes: #5054Closes: #5062
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5062
Pull-request-sha: 5ca2f27281
Change-Id: I599b9c8befa64d9a59a35ad7dd84ff400e3aa647
Fixed bug where a table that would have a column label overlap with a plain
column name, such as "foo.id AS foo_id" vs. "foo.foo_id", would prematurely
generate the ``._label`` attribute for a column before this overlap could
be detected due to the use of the ``index=True`` or ``unique=True`` flag on
the column in conjunction with the default naming convention of
``"column_0_label"``. This would then lead to failures when ``._label``
were used later to generate a bound parameter name, in particular those
used by the ORM when generating the WHERE clause for an UPDATE statement.
The issue has been fixed by using an alternate ``._label`` accessor for DDL
generation that does not affect the state of the :class:`.Column`. The
accessor also bypasses the key-deduplication step as it is not necessary
for DDL, the naming is now consistently ``"<tablename>_<columnname>"``
without any subsequent numeric symbols when used in DDL.
Fixes: #4911
Change-Id: Iabf5fd3250738d800d6e41a2a3a27a7ce2405e7d
A major refactoring of all the functions handle all detection of
Core argument types as well as perform coercions into a new class hierarchy
based on "roles", each of which identify a syntactical location within a
SQL statement. In contrast to the ClauseElement hierarchy that identifies
"what" each object is syntactically, the SQLRole hierarchy identifies
the "where does it go" of each object syntactically. From this we define
a consistent type checking and coercion system that establishes well
defined behviors.
This is a breakout of the patch that is reorganizing select()
constructs to no longer be in the FromClause hierarchy.
Also includes a rename of as_scalar() into scalar_subquery(); deprecates
automatic coercion to scalar_subquery().
Partially-fixes: #4617
Change-Id: I26f1e78898693c6b99ef7ea2f4e7dfd0e8e1a1bd
Applied on top of a pure run of black -l 79 in
I7eda77fed3d8e73df84b3651fd6cfcfe858d4dc9, this set of changes
resolves all remaining flake8 conditions for those codes
we have enabled in setup.cfg.
Included are resolutions for all remaining flake8 issues
including shadowed builtins, long lines, import order, unused
imports, duplicate imports, and docstring issues.
Change-Id: I4f72d3ba1380dd601610ff80b8fb06a2aff8b0fe
This is a straight reformat run using black as is, with no edits
applied at all.
The black run will format code consistently, however in
some cases that are prevalent in SQLAlchemy code it produces
too-long lines. The too-long lines will be resolved in the
following commit that will resolve all remaining flake8 issues
including shadowed builtins, long lines, import order, unused
imports, duplicate imports, and docstring issues.
Change-Id: I7eda77fed3d8e73df84b3651fd6cfcfe858d4dc9
test_compiler is mostly related to SELECT statements as well
as smaller SQL elements. While it still has some DDL related
tests, move out all the remaining insert/update tests into
the already present test_insert.py, test_update.py
Fixes: #2630
Change-Id: I4167618543fd1235d12d1717c8c629d2374b325a
Fixed bug where the multi-table support for UPDATE and DELETE statements
did not consider the additional FROM elements as targets for correlation,
when a correlated SELECT were also combined with the statement. This
change now includes that a SELECT statement in the WHERE clause for such a
statement will try to auto-correlate back to these additional tables in the
parent UPDATE/DELETE or unconditionally correlate if
:meth:`.Select.correlate` is used. Note that auto-correlation raises an
error if the SELECT statement would have no FROM clauses as a result, which
can now occur if the parent UPDATE/DELETE specifies the same tables in its
additional set of tables ; specify :meth:`.Select.correlate` explicitly to
resolve.
Change-Id: Ie11eaad7e49af3f59df11691b104d6359341bdae
Fixes: #4313
The :class:`.Update` construct now accommodates a :class:`.Join` object
as supported by MySQL for UPDATE..FROM. As the construct already
accepted an alias object for a similar purpose, the feature of UPDATE
against a non-table was already implied so this has been added.
Change-Id: I7b2bca627849384d5377abb0c94626463e4fad04
Fixes: #3645
Corrects some warnings and adds tox config. Adds DeprecationWarning
to the error category. Large sweep for string literals w/ backslashes
as this is common in docstrings
Co-authored-by: Andrii Soldatenko
Fixes: #3886
Change-Id: Ia7c838dfbbe70b262622ed0803d581edc736e085
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/337
statement. This feature is available by passing the
:paramref:`~.sqlalchemy.sql.expression.update.preserve_parameter_order`
flag either to the core :class:`.Update` construct or alternatively
adding it to the :paramref:`.Query.update.update_args` dictionary at
the ORM-level, also passing the parameters themselves as a list of 2-tuples.
Thanks to Gorka Eguileor for implementation and tests.
adapted from pullreq github:200
would produce an empty WHERE clause when an empty :func:`.and_()`
or :func:`.or_()` or other blank expression were applied. This is
now consistent with that of :func:`.select`.
fixes#3045
a no-name :class:`.BindParameter` is received, e.g. via :func:`.sql.literal`
or similar; the "key" of the bind param is used as the key within
.c. rather than the rendered name. Since these binds have "anonymous"
names in any case, this allows individual bound parameters to
have their own name within a selectable if they are otherwise unlabeled.
fixes#2974
MySQL, to correctly render the SET clause among multiple columns
with the same name across tables. This also changes the name used for
the bound parameter in the SET clause to "<tablename>_<colname>" for
the non-primary table only; as this parameter is typically specified
using the :class:`.Column` object directly this should not have an
impact on applications. The fix takes effect for both
:meth:`.Table.update` as well as :meth:`.Query.update` in the ORM.
[ticket:2912]
table is a SELECT with its own bound parameters, where the positioning
of the bound parameters would be reversed versus the statement
itself when using MySQL's special syntax.
[ticket:2768]
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.
- enhancements to test suite including ability to set up a testing engine
for a whole test class, fixes to how noseplugin sets up/tears
down per-class context
requires that the updated table be present
in the FROM clause when an alias of that
table is also present in the FROM clause.
The updated table is now always present
in the FROM, when FROM is present
in the first place. Courtesy sayap.
[ticket:2468]
Mike Bayer