From 8acbc2624fb4b457e47fab93e6a44a1e37caeddc Mon Sep 17 00:00:00 2001 From: raylu Date: Wed, 20 Mar 2019 17:22:19 -0400 Subject: Expand joins when calculating PostgreSQL "WITH FOR UPDATE OF" Modified the :paramref:`.Select.with_for_update.of` parameter so that if a join or other composed selectable is passed, the individual :class:`.Table` objects will be filtered from it, allowing one to pass a join() object to the parameter, as occurs normally when using joined table inheritance with the ORM. Pull request courtesy Raymond Lu. Fixes: #4550 Co-authored-by: Mike Bayer Closes: #4551 Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/4551 Pull-request-sha: 452da77d154a4087d530456db1c9af207d65cef4 Change-Id: If4b7c231f7b71190d7245543959fb5c3351125a1 --- lib/sqlalchemy/sql/util.py | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'lib/sqlalchemy/sql/util.py') diff --git a/lib/sqlalchemy/sql/util.py b/lib/sqlalchemy/sql/util.py index 5a44f873d..3077840c6 100644 --- a/lib/sqlalchemy/sql/util.py +++ b/lib/sqlalchemy/sql/util.py @@ -29,11 +29,13 @@ from .elements import ColumnElement from .elements import Null from .elements import UnaryExpression from .schema import Column +from .selectable import Alias from .selectable import FromClause from .selectable import FromGrouping from .selectable import Join from .selectable import ScalarSelect from .selectable import SelectBase +from .selectable import TableClause from .. import exc from .. import util @@ -339,6 +341,20 @@ def surface_selectables(clause): stack.append(elem.element) +def surface_selectables_only(clause): + stack = [clause] + while stack: + elem = stack.pop() + if isinstance(elem, (TableClause, Alias)): + yield elem + if isinstance(elem, Join): + stack.extend((elem.left, elem.right)) + elif isinstance(elem, FromGrouping): + stack.append(elem.element) + elif isinstance(elem, ColumnClause): + stack.append(elem.table) + + def surface_column_elements(clause, include_scalar_selects=True): """traverse and yield only outer-exposed column elements, such as would be addressable in the WHERE clause of a SELECT if this element were -- cgit v1.2.1