fix instrument of typed psycopg sql (#4171)

* fix instrument of typed psycopg sql

The instrumentation is not working when using [typed `SQL`](https://www.psycopg.org/psycopg3/docs/api/sql.html) from psycopg (only when using the `Composed` type, that is returned when the query is formated).

```python
from psycopg.sql import SQL
query = SQL("SELECT * FROM test")
```

This fixes it by checking the `Composable` base class instead of the more restricted `Composed`.

* add changelog

* fix tests for python 3.9

using an identifier requires a real connection, I just replaced it since we only want to test with a composed.

---------

Co-authored-by: Riccardo Magliocchetti <riccardo.magliocchetti@gmail.com>

CHANGELOG.md

@@ -104,6 +104,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#3922](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3922))
 - `opentelemetry-instrumentation-urllib3`: fix multiple arguments error
   ([#4144](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/4144))
+- `opentelemetry-instrumentation-psycopg`: Fix instrument of typed psycopg sql
+  ([#4078](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/4171))
 - `opentelemetry-instrumentation-aiohttp-server`: fix HTTP error inconsistencies
   ([#4175](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/4175))
 
@@ -112,7 +114,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `opentelemetry-instrumentation-logging`: Inject span context attributes into logging LogRecord only if configured to do so
   ([#4112](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/4112))
 - `opentelemetry-instrumentation-django`: Drop support for Django < 2.0
-  ([#3848](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/4083))
+  ([#4083](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/4083))
 
 ## Version 1.39.0/0.60b0 (2025-12-03)
 

instrumentation/opentelemetry-instrumentation-psycopg/src/opentelemetry/instrumentation/psycopg/__init__.py

@@ -147,7 +147,7 @@ import logging
 from typing import Any, Callable, Collection, TypeVar
 
 import psycopg  # pylint: disable=import-self
-from psycopg.sql import Composed  # pylint: disable=no-name-in-module
+from psycopg.sql import Composable  # pylint: disable=no-name-in-module
 
 from opentelemetry.instrumentation import dbapi
 from opentelemetry.instrumentation.instrumentor import BaseInstrumentor
@@ -338,7 +338,7 @@ class CursorTracer(dbapi.CursorTracer):
             return ""
 
         statement = args[0]
-        if isinstance(statement, Composed):
+        if isinstance(statement, Composable):
             statement = statement.as_string(cursor)
 
         # `statement` can be empty string. See #2643
@@ -353,7 +353,7 @@ class CursorTracer(dbapi.CursorTracer):
             return ""
 
         statement = args[0]
-        if isinstance(statement, Composed):
+        if isinstance(statement, Composable):
             statement = statement.as_string(cursor)
         return statement
 

instrumentation/opentelemetry-instrumentation-psycopg/tests/test_psycopg_integration.py

@@ -17,6 +17,7 @@ import types
 from unittest import IsolatedAsyncioTestCase, mock
 
 import psycopg
+from psycopg.sql import SQL, Composed
 
 import opentelemetry.instrumentation.psycopg
 from opentelemetry.instrumentation.psycopg import PsycopgInstrumentor
@@ -34,6 +35,8 @@ class MockCursor:
     callproc = mock.MagicMock(spec=types.MethodType)
     callproc.__name__ = "callproc"
 
+    connection = None
+
     rowcount = "SomeRowCount"
 
     def __init__(self, *args, **kwargs):
@@ -348,6 +351,41 @@ class TestPostgresqlIntegration(PostgresqlIntegrationTestMixin, TestBase):
         spans_list = self.memory_exporter.get_finished_spans()
         self.assertEqual(len(spans_list), 1)
 
+    def test_instrument_connection_typed_sql_query(self):
+        cnx = psycopg.connect(database="test")
+        query = SQL("SELECT * FROM test")
+
+        cnx = PsycopgInstrumentor().instrument_connection(cnx)
+
+        self.assertTrue(issubclass(cnx.cursor_factory, MockCursor))
+
+        cursor = cnx.cursor()
+        cursor.execute(query)
+
+        spans_list = self.memory_exporter.get_finished_spans()
+        self.assertEqual(len(spans_list), 1)
+        self.assertEqual(spans_list[0].name, "SELECT")
+        self.assertEqual(
+            spans_list[0].attributes["db.statement"], "SELECT * FROM test"
+        )
+
+    def test_instrument_connection_composed_query(self):
+        cnx = psycopg.connect(database="test")
+        query: Composed = SQL("SELECT * FROM test").format()
+
+        cnx = PsycopgInstrumentor().instrument_connection(cnx)
+        self.assertTrue(issubclass(cnx.cursor_factory, MockCursor))
+
+        cursor = cnx.cursor()
+        cursor.execute(query)
+
+        spans_list = self.memory_exporter.get_finished_spans()
+        self.assertEqual(len(spans_list), 1)
+        self.assertEqual(spans_list[0].name, "SELECT")
+        self.assertEqual(
+            spans_list[0].attributes["db.statement"], "SELECT * FROM test"
+        )
+
     # pylint: disable=unused-argument
     def test_instrument_connection_with_instrument(self):
         cnx = psycopg.connect(database="test")