"auto increment" column has been changed, such that autoincrement is no longer implicitly enabled for a :class:`.Table` that has a composite primary key. In order to accommodate being able to enable autoincrement for a composite PK member column while at the same time maintaining SQLAlchemy's long standing behavior of enabling implicit autoincrement for a single integer primary key, a third state has been added to the :paramref:`.Column.autoincrement` parameter ``"auto"``, which is now the default. fixes #3216 - The MySQL dialect no longer generates an extra "KEY" directive when generating CREATE TABLE DDL for a table using InnoDB with a composite primary key with AUTO_INCREMENT on a column that isn't the first column; to overcome InnoDB's limitation here, the PRIMARY KEY constraint is now generated with the AUTO_INCREMENT column placed first in the list of columns.
as :class:`.TypeDecorator` objects.
dialect on a type where MySQL does not support CAST; MySQL only supports CAST on a subset of datatypes. SQLAlchemy has for a long time just omitted the CAST for unsupported types in the case of MySQL. While we don't want to change this now, we emit a warning to show that it's taken place. A warning is also emitted when a CAST is used with an older MySQL version (< 4) that doesn't support CAST at all, it's skipped in this case as well. fixes #3237
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
on an index needed to have the same quoting for quoted names in order to be recognized. The fix makes the quotes optional but also provides the old behavior for backwards compatibility with those using the workaround. fixes #3085
is currently being supported in addition to nose, and will likely be preferred to nose going forward. The nose plugin system used by SQLAlchemy has been split out so that it works under pytest as well. There are no plans to drop support for nose at the moment and we hope that the test suite itself can continue to remain as agnostic of testing platform as possible. See the file README.unittests.rst for updated information on running tests with pytest. The test plugin system has also been enhanced to support running tests against mutiple database URLs at once, by specifying the ``--db`` and/or ``--dburi`` flags multiple times. This does not run the entire test suite for each database, but instead allows test cases that are specific to certain backends make use of that backend as the test is run. When using pytest as the test runner, the system will also run specific test suites multiple times, once for each database, particularly those tests within the "dialect suite". The plan is that the enhanced system will also be used by Alembic, and allow Alembic to run migration operation tests against multiple backends in one run, including third-party backends not included within Alembic itself. Third party dialects and extensions are also encouraged to standardize on SQLAlchemy's test suite as a basis; see the file README.dialects.rst for background on building out from SQLAlchemy's test platform.
type such as "charset" and "collation". While MySQL wants all character- based CAST calls to use the CHAR type, we now create a real CHAR object at CAST time and copy over all the parameters it has, so that an expression like ``cast(x, mysql.TEXT(charset='utf8'))`` will render ``CAST(t.col AS CHAR CHARACTER SET utf8)``. - Added new "unicode returns" detection to the MySQL dialect and to the default dialect system overall, such that any dialect can add extra "tests" to the on-first-connect "does this DBAPI return unicode directly?" detection. In this case, we are adding a check specifically against the "utf8" encoding with an explicit "utf8_bin" collation type (after checking that this collation is available) to test for some buggy unicode behavior observed with MySQLdb version 1.2.3. While MySQLdb has resolved this issue as of 1.2.4, the check here should guard against regressions. The change also allows the "unicode" checks to log in the engine logs, which was not previously the case. [ticket:2906]