Don't barf on Composite passed to execute_values()

Close #794

NEWS

@@ -43,6 +43,8 @@ What's new in psycopg 2.7.6
 - Fixed hang trying to :sql:`COPY` via `~cursor.execute()` (:ticket:`#781`).
 - Fixed segfault accessing the `connection.readonly` and
   `connection.deferrable` repeatedly (:ticket:`#790`).
+- `~psycopg2.extras.execute_values()` accepts `~psycopg2.sql.Composable`
+  objects (#794).
 - `~psycopg2.errorcodes` map updated to PostgreSQL 11.
 
 

lib/extras.py

@@ -1254,6 +1254,10 @@ def execute_values(cur, sql, argslist, template=None, page_size=100):
         [(1, 20, 3), (4, 50, 6), (7, 8, 9)])
 
     '''
+    from psycopg2.sql import Composable
+    if isinstance(sql, Composable):
+        sql = sql.as_string(cur)
+
     # we can't just use sql % vals because vals is bytes: if sql is bytes
     # there will be some decoding error because of stupid codec used, and Py3
     # doesn't implement % on bytes.

tests/test_fast_executemany.py

@@ -83,6 +83,16 @@ class TestExecuteBatch(FastExecuteTestMixin, testutils.ConnectingTestCase):
         cur.execute("select id, val from testfast order by id")
         self.assertEqual(cur.fetchall(), [(i, i * 10) for i in range(1000)])
 
+    def test_composed(self):
+        from psycopg2 import sql
+        cur = self.conn.cursor()
+        psycopg2.extras.execute_batch(cur,
+            sql.SQL("insert into {0} (id, val) values (%s, %s)")
+                .format(sql.Identifier('testfast')),
+            ((i, i * 10) for i in range(1000)))
+        cur.execute("select id, val from testfast order by id")
+        self.assertEqual(cur.fetchall(), [(i, i * 10) for i in range(1000)])
+
     def test_pages(self):
         cur = self.conn.cursor()
         psycopg2.extras.execute_batch(cur,
@@ -169,6 +179,16 @@ class TestExecuteValues(FastExecuteTestMixin, testutils.ConnectingTestCase):
         cur.execute("select id, val from testfast order by id")
         self.assertEqual(cur.fetchall(), [(i, i * 10) for i in range(1000)])
 
+    def test_composed(self):
+        from psycopg2 import sql
+        cur = self.conn.cursor()
+        psycopg2.extras.execute_values(cur,
+            sql.SQL("insert into {0} (id, val) values %s")
+                .format(sql.Identifier('testfast')),
+            ((i, i * 10) for i in range(1000)))
+        cur.execute("select id, val from testfast order by id")
+        self.assertEqual(cur.fetchall(), [(i, i * 10) for i in range(1000)])
+
     def test_pages(self):
         cur = self.conn.cursor()
         psycopg2.extras.execute_values(cur,