From 3b4bbbb2a3d337d0af1ba5ccb0d29d1c48735e83 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Sat, 15 Aug 2020 15:08:09 -0400 Subject: Create a real type for Tuple() and handle appropriately in compiler Improved the :func:`_sql.tuple_` construct such that it behaves predictably when used in a columns-clause context. The SQL tuple is not supported as a "SELECT" columns clause element on most backends; on those that do (PostgreSQL, not surprisingly), the Python DBAPI does not have a "nested type" concept so there are still challenges in fetching rows for such an object. Use of :func:`_sql.tuple_` in a :func:`_sql.select` or :class:`_orm.Query` will now raise a :class:`_exc.CompileError` at the point at which the :func:`_sql.tuple_` object is seen as presenting itself for fetching rows (i.e., if the tuple is in the columns clause of a subquery, no error is raised). For ORM use,the :class:`_orm.Bundle` object is an explicit directive that a series of columns should be returned as a sub-tuple per row and is suggested by the error message. Additionally ,the tuple will now render with parenthesis in all contexts. Previously, the parenthesization would not render in a columns context leading to non-defined behavior. As part of this change, Tuple receives a dedicated datatype which appears to allow us the very desirable change of removing the bindparam._expanding_in_types attribute as well as ClauseList._tuple_values (which might already have not been needed due to #4645). Fixes: #5127 Change-Id: Iecafa0e0aac2f1f37ec8d0e1631d562611c90200 --- lib/sqlalchemy/orm/evaluator.py | 3 +++ 1 file changed, 3 insertions(+) (limited to 'lib/sqlalchemy/orm') diff --git a/lib/sqlalchemy/orm/evaluator.py b/lib/sqlalchemy/orm/evaluator.py index caa9ffe10..21d5e72d4 100644 --- a/lib/sqlalchemy/orm/evaluator.py +++ b/lib/sqlalchemy/orm/evaluator.py @@ -113,6 +113,9 @@ class EvaluatorCompiler(object): get_corresponding_attr = operator.attrgetter(key) return lambda obj: get_corresponding_attr(obj) + def visit_tuple(self, clause): + return self.visit_clauselist(clause) + def visit_clauselist(self, clause): evaluators = list(map(self.process, clause.clauses)) if clause.operator is operators.or_: -- cgit v1.2.1