From: Daniele Varrazzo <daniele.varrazzo@gmail.com>
Date: Wed, 10 Feb 2021 17:50:03 +0000 (+0100)
Subject: Make sue ServerCursor.execute() can be used more than once
X-Git-Tag: 3.0.dev0~115^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e38d1460f6f8f87ecfb789c6053100c5881afd64;p=thirdparty%2Fpsycopg.git

Make sue ServerCursor.execute() can be used more than once
---

diff --git a/psycopg3/psycopg3/server_cursor.py b/psycopg3/psycopg3/server_cursor.py
index 289485edc..e0e66e999 100644
--- a/psycopg3/psycopg3/server_cursor.py
+++ b/psycopg3/psycopg3/server_cursor.py
@@ -53,6 +53,12 @@ class ServerCursorHelper(Generic[ConnectionType]):
     ) -> PQGen[None]:
         """Generator implementing `ServerCursor.execute()`."""
         conn = cur._conn
+
+        # If the cursor is being reused, the previous one must be closed.
+        if self.described:
+            yield from self._close_gen(cur)
+            self.described = False
+
         yield from cur._start_query(query)
         pgq = cur._convert_query(query, params)
         cur._execute_send(pgq)
diff --git a/tests/test_server_cursor.py b/tests/test_server_cursor.py
index ff9c2559b..78d456507 100644
--- a/tests/test_server_cursor.py
+++ b/tests/test_server_cursor.py
@@ -94,6 +94,20 @@ def test_warn_close(conn, recwarn):
     assert ".close()" in str(recwarn.pop(ResourceWarning).message)
 
 
+def test_execute_reuse(conn):
+    with conn.cursor("foo") as cur:
+        cur.execute("select generate_series(1, %s) as foo", (3,))
+        assert cur.fetchone() == (1,)
+
+        cur.execute(
+            "select %s::text as bar, %s::text as baz", ("hello", "world")
+        )
+        assert cur.fetchone() == ("hello", "world")
+        assert cur.description[0].name == "bar"
+        assert cur.description[0].type_code == cur.adapters.types["text"].oid
+        assert cur.description[1].name == "baz"
+
+
 def test_executemany(conn):
     cur = conn.cursor("foo")
     with pytest.raises(e.NotSupportedError):
diff --git a/tests/test_server_cursor_async.py b/tests/test_server_cursor_async.py
index 685c55928..4a3465535 100644
--- a/tests/test_server_cursor_async.py
+++ b/tests/test_server_cursor_async.py
@@ -96,6 +96,20 @@ async def test_warn_close(aconn, recwarn):
     assert ".close()" in str(recwarn.pop(ResourceWarning).message)
 
 
+async def test_execute_reuse(aconn):
+    async with aconn.cursor("foo") as cur:
+        await cur.execute("select generate_series(1, %s) as foo", (3,))
+        assert await cur.fetchone() == (1,)
+
+        await cur.execute(
+            "select %s::text as bar, %s::text as baz", ("hello", "world")
+        )
+        assert await cur.fetchone() == ("hello", "world")
+        assert cur.description[0].name == "bar"
+        assert cur.description[0].type_code == cur.adapters.types["text"].oid
+        assert cur.description[1].name == "baz"
+
+
 async def test_executemany(aconn):
     cur = aconn.cursor("foo")
     with pytest.raises(e.NotSupportedError):