From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Tue, 21 Mar 2023 17:32:41 +0000 (-0400)
Subject: return None for no parententity on Proxy
X-Git-Tag: rel_2_0_8~20^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c8fb843a2d92e5d8d2271d46ddde02a2c79ee94c;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

return None for no parententity on Proxy

Fixed regression where accessing the expression value of a hybrid property
on a class that was either unmapped or not-yet-mapped (such as calling upon
it within a :func:`_orm.declared_attr` method) would raise an internal
error, as an internal fetch for the parent class' mapper would fail and an
instruction for this failure to be ignored were inadvertently removed in
2.0.

Fixes: #9519
Change-Id: If195d26a5ddd2312a373004eb7a1403e1d11e7a4
---

diff --git a/doc/build/changelog/unreleased_20/9519.rst b/doc/build/changelog/unreleased_20/9519.rst
new file mode 100644
index 0000000000..c5a24a4428
--- /dev/null
+++ b/doc/build/changelog/unreleased_20/9519.rst
@@ -0,0 +1,10 @@
+.. change::
+    :tags: bug, orm
+    :tickets: 9519
+
+    Fixed regression where accessing the expression value of a hybrid property
+    on a class that was either unmapped or not-yet-mapped (such as calling upon
+    it within a :func:`_orm.declared_attr` method) would raise an internal
+    error, as an internal fetch for the parent class' mapper would fail and an
+    instruction for this failure to be ignored were inadvertently removed in
+    2.0.
diff --git a/lib/sqlalchemy/orm/attributes.py b/lib/sqlalchemy/orm/attributes.py
index f33364c624..3a60eda4f2 100644
--- a/lib/sqlalchemy/orm/attributes.py
+++ b/lib/sqlalchemy/orm/attributes.py
@@ -611,11 +611,11 @@ def create_proxied_attribute(
 
         @property
         def _parententity(self):
-            return inspection.inspect(self.class_)
+            return inspection.inspect(self.class_, raiseerr=False)
 
         @property
         def parent(self):
-            return inspection.inspect(self.class_)
+            return inspection.inspect(self.class_, raiseerr=False)
 
         _is_internal_proxy = True
 
diff --git a/test/ext/test_hybrid.py b/test/ext/test_hybrid.py
index 73967cdd00..69e9c13351 100644
--- a/test/ext/test_hybrid.py
+++ b/test/ext/test_hybrid.py
@@ -15,7 +15,9 @@ from sqlalchemy import String
 from sqlalchemy import testing
 from sqlalchemy.ext import hybrid
 from sqlalchemy.orm import aliased
+from sqlalchemy.orm import column_property
 from sqlalchemy.orm import declarative_base
+from sqlalchemy.orm import declared_attr
 from sqlalchemy.orm import relationship
 from sqlalchemy.orm import Session
 from sqlalchemy.orm import synonym
@@ -421,6 +423,61 @@ class PropertyExpressionTest(fixtures.TestBase, AssertsCompiledSQL):
 
         return A
 
+    def test_access_from_unmapped(self):
+        """test #9519"""
+
+        class DnsRecord:
+            name = Column("name", String)
+
+            @hybrid.hybrid_property
+            def ip_value(self):
+                return self.name[1:3]
+
+            @ip_value.expression
+            def ip_value(cls):
+                return func.substring(cls.name, 1, 3)
+
+        raw_attr = DnsRecord.ip_value
+        is_(raw_attr._parententity, None)
+
+        self.assert_compile(
+            raw_attr, "substring(name, :substring_1, :substring_2)"
+        )
+
+        self.assert_compile(
+            select(DnsRecord.ip_value),
+            "SELECT substring(name, :substring_2, :substring_3) "
+            "AS substring_1",
+        )
+
+    def test_access_from_not_yet_mapped(self, decl_base):
+        """test #9519"""
+
+        class DnsRecord(decl_base):
+            __tablename__ = "dnsrecord"
+            id = Column(Integer, primary_key=True)
+            name = Column(String, unique=False, nullable=False)
+
+            @declared_attr
+            def thing(cls):
+                return column_property(cls.ip_value)
+
+            name = Column("name", String)
+
+            @hybrid.hybrid_property
+            def ip_value(self):
+                return self.name[1:3]
+
+            @ip_value.expression
+            def ip_value(cls):
+                return func.substring(cls.name, 1, 3)
+
+        self.assert_compile(
+            select(DnsRecord.thing),
+            "SELECT substring(dnsrecord.name, :substring_2, :substring_3) "
+            "AS substring_1 FROM dnsrecord",
+        )
+
     def test_labeling_for_unnamed(self, _unnamed_expr_fixture):
         A = _unnamed_expr_fixture