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| author | Mike Bayer <mike_mp@zzzcomputing.com> | 2019-06-13 12:37:22 -0400 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2019-07-06 13:02:22 -0400 |
| commit | ef7ff058eb67d73ebeac7b125ab2a7806e14629c (patch) | |
| tree | 9a09162961f7bcdb6d16837adacabb99f10b4410 /lib/sqlalchemy/sql/expression.py | |
| parent | 1ce98ca83a4b2da12e52aa0f4ab181c83063abc2 (diff) | |
| download | sqlalchemy-ef7ff058eb67d73ebeac7b125ab2a7806e14629c.tar.gz | |
SelectBase no longer a FromClause
As part of the SQLAlchemy 2.0 migration project, a conceptual change has
been made to the role of the :class:`.SelectBase` class hierarchy,
which is the root of all "SELECT" statement constructs, in that they no
longer serve directly as FROM clauses, that is, they no longer subclass
:class:`.FromClause`. For end users, the change mostly means that any
placement of a :func:`.select` construct in the FROM clause of another
:func:`.select` requires first that it be wrapped in a subquery first,
which historically is through the use of the :meth:`.SelectBase.alias`
method, and is now also available through the use of
:meth:`.SelectBase.subquery`. This was usually a requirement in any
case since several databases don't accept unnamed SELECT subqueries
in their FROM clause in any case.
See the documentation in this change for lots more detail.
Fixes: #4617
Change-Id: I0f6174ee24b9a1a4529168e52e855e12abd60667
Diffstat (limited to 'lib/sqlalchemy/sql/expression.py')
| -rw-r--r-- | lib/sqlalchemy/sql/expression.py | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py index b04355cf5..7ce822669 100644 --- a/lib/sqlalchemy/sql/expression.py +++ b/lib/sqlalchemy/sql/expression.py @@ -16,6 +16,7 @@ class. __all__ = [ "Alias", + "AliasedReturnsRows", "any_", "all_", "ClauseElement", @@ -76,6 +77,7 @@ __all__ = [ "union_all", "update", "within_group", + "Subquery", "TableSample", "tablesample", ] @@ -132,6 +134,7 @@ from .functions import Function # noqa from .functions import FunctionElement # noqa from .functions import modifier # noqa from .selectable import Alias # noqa +from .selectable import AliasedReturnsRows # noqa from .selectable import CompoundSelect # noqa from .selectable import CTE # noqa from .selectable import Exists # noqa @@ -148,10 +151,12 @@ from .selectable import ScalarSelect # noqa from .selectable import Select # noqa from .selectable import Selectable # noqa from .selectable import SelectBase # noqa +from .selectable import Subquery # noqa from .selectable import subquery # noqa from .selectable import TableClause # noqa from .selectable import TableSample # noqa from .selectable import TextAsFrom # noqa +from .selectable import TextualSelect # noqa from .visitors import Visitable # noqa from ..util.langhelpers import public_factory # noqa |