From b4c6cfc2fde6c652e79ca157f8023a3f8941bc3c Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Thu, 14 Jan 2021 11:18:58 -0500 Subject: [PATCH] Use UnsupportedCompilationError for no default compiler Fixed issue where the stringification that is sometimes called when attempting to generate the "key" for the ``.c`` collection on a selectable would fail if the column were an unlabeled custom SQL construct using the ``sqlalchemy.ext.compiler`` extension, and did not provide a default compilation form; while this seems like an unusual case, it can get invoked for some ORM scenarios such as when the expression is used in an "order by" in combination with joined eager loading. The issue is that the lack of a default compiler function was raising :class:`.CompileError` and not :class:`.UnsupportedCompilationError`. Fixes: #5836 Change-Id: I5af243b2c70c7dcca4b212a3869c3017a50c132b --- doc/build/changelog/unreleased_13/5836.rst | 13 +++++++++++ lib/sqlalchemy/exc.py | 6 +++--- lib/sqlalchemy/ext/compiler.py | 16 ++++++++------ test/ext/test_compiler.py | 25 ++++++++++++++++++++-- 4 files changed, 49 insertions(+), 11 deletions(-) create mode 100644 doc/build/changelog/unreleased_13/5836.rst diff --git a/doc/build/changelog/unreleased_13/5836.rst b/doc/build/changelog/unreleased_13/5836.rst new file mode 100644 index 0000000000..0ddfb9a8db --- /dev/null +++ b/doc/build/changelog/unreleased_13/5836.rst @@ -0,0 +1,13 @@ +.. change:: + :tags: bug, ext + :tickets: 5836 + + Fixed issue where the stringification that is sometimes called when + attempting to generate the "key" for the ``.c`` collection on a selectable + would fail if the column were an unlabeled custom SQL construct using the + ``sqlalchemy.ext.compiler`` extension, and did not provide a default + compilation form; while this seems like an unusual case, it can get invoked + for some ORM scenarios such as when the expression is used in an "order by" + in combination with joined eager loading. The issue is that the lack of a + default compiler function was raising :class:`.CompileError` and not + :class:`.UnsupportedCompilationError`. diff --git a/lib/sqlalchemy/exc.py b/lib/sqlalchemy/exc.py index b031c1610e..08b1bb060f 100644 --- a/lib/sqlalchemy/exc.py +++ b/lib/sqlalchemy/exc.py @@ -179,10 +179,10 @@ class UnsupportedCompilationError(CompileError): code = "l7de" - def __init__(self, compiler, element_type): + def __init__(self, compiler, element_type, message=None): super(UnsupportedCompilationError, self).__init__( - "Compiler %r can't render element of type %s" - % (compiler, element_type) + "Compiler %r can't render element of type %s%s" + % (compiler, element_type, ": %s" % message if message else "") ) diff --git a/lib/sqlalchemy/ext/compiler.py b/lib/sqlalchemy/ext/compiler.py index 5a31173eca..47fb6720ba 100644 --- a/lib/sqlalchemy/ext/compiler.py +++ b/lib/sqlalchemy/ext/compiler.py @@ -425,9 +425,11 @@ def compiles(class_, *specs): return existing_dispatch(element, compiler, **kw) except exc.UnsupportedCompilationError as uce: util.raise_( - exc.CompileError( - "%s construct has no default " - "compilation handler." % type(element) + exc.UnsupportedCompilationError( + compiler, + type(element), + message="%s construct has no default " + "compilation handler." % type(element), ), from_=uce, ) @@ -476,9 +478,11 @@ class _dispatcher(object): fn = self.specs["default"] except KeyError as ke: util.raise_( - exc.CompileError( - "%s construct has no default " - "compilation handler." % type(element) + exc.UnsupportedCompilationError( + compiler, + type(element), + message="%s construct has no default " + "compilation handler." % type(element), ), replace_context=ke, ) diff --git a/test/ext/test_compiler.py b/test/ext/test_compiler.py index 058c1dfd77..8d129a9986 100644 --- a/test/ext/test_compiler.py +++ b/test/ext/test_compiler.py @@ -151,13 +151,33 @@ class UserDefinedTest(fixtures.TestBase, AssertsCompiledSQL): return "mythingy" assert_raises_message( - exc.CompileError, + exc.UnsupportedCompilationError, " " "construct has no default compilation handler.", str, MyThingy(), ) + def test_no_default_proxy_generation(self): + class my_function(FunctionElement): + name = "my_function" + type = Numeric() + + @compiles(my_function, "sqlite") + def sqlite_my_function(element, compiler, **kw): + return "my_function(%s)" % compiler.process(element.clauses, **kw) + + t1 = table("t1", column("q")) + stmt = select(my_function(t1.c.q)) + + self.assert_compile( + stmt, + "SELECT my_function(t1.q) AS my_function_1 FROM t1", + dialect="sqlite", + ) + + eq_(stmt.selected_columns.keys(), [stmt._raw_columns[0].anon_label]) + def test_no_default_message(self): class MyThingy(ClauseElement): pass @@ -167,7 +187,8 @@ class UserDefinedTest(fixtures.TestBase, AssertsCompiledSQL): return "mythingy" assert_raises_message( - exc.CompileError, + exc.UnsupportedCompilationError, + "Compiler .*StrSQLCompiler.* can't .* " " " "construct has no default compilation handler.", str, -- 2.47.2