From dd2ff2af56b99d69d508fa6169be4011283593e2 Mon Sep 17 00:00:00 2001
From: Daniele Varrazzo <daniele.varrazzo@gmail.com>
Date: Wed, 16 Jun 2021 23:55:11 +0100
Subject: [PATCH] Fix regression with named `sql.Placeholder`

Close #1291.
---
 NEWS              | 6 ++++++
 lib/sql.py        | 2 +-
 tests/test_sql.py | 4 ++++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/NEWS b/NEWS
index 8b7818a3..c6f9ab1e 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,12 @@
 Current release
 ---------------
 
+What's new in psycopg 2.9.1
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Fix regression with named `sql.Placeholder` (:ticket:`1291`).
+
+
 What's new in psycopg 2.9
 -------------------------
 
diff --git a/lib/sql.py b/lib/sql.py
index 1c780902..13548da4 100644
--- a/lib/sql.py
+++ b/lib/sql.py
@@ -442,7 +442,7 @@ class Placeholder(Composable):
 
     def as_string(self, context):
         if self._wrapped is not None:
-            return f"%({self._wrapped})"
+            return f"%({self._wrapped})s"
         else:
             return "%s"
 
diff --git a/tests/test_sql.py b/tests/test_sql.py
index 8fb1f114..407c07df 100755
--- a/tests/test_sql.py
+++ b/tests/test_sql.py
@@ -393,6 +393,10 @@ class PlaceholderTest(ConnectingTestCase):
         self.assert_(sql.Placeholder('foo') != sql.Placeholder())
         self.assert_(sql.Placeholder('foo') != sql.Literal('foo'))
 
+    def test_as_string(self):
+        self.assertEqual(sql.Placeholder().as_string(self.conn), "%s")
+        self.assertEqual(sql.Placeholder('foo').as_string(self.conn), "%(foo)s")
+
 
 class ValuesTest(ConnectingTestCase):
     def test_null(self):