Add executemany() in prepared statement

Author: fantix

asyncpg/prepared_stmt.py

@@ -196,6 +196,25 @@ async def fetchrow(self, *args, timeout=None):
             return None
         return data[0]
 
+    @connresource.guarded
+    async def executemany(self, args, *, timeout: float=None):
+        """Execute the statement for each sequence of arguments in *args*.
+
+        :param args: An (async) iterable containing sequences of arguments.
+        :param float timeout: Optional timeout value in seconds.
+        :return None: This method discards the results of the operations.
+
+        .. versionadded:: 0.16.0
+        """
+        protocol = self._connection._protocol
+        try:
+            return await protocol.bind_execute_many(
+                self._state, args, '', timeout)
+        except exceptions.OutdatedSchemaCacheError:
+            await self._connection.reload_schema_state()
+            self._state.mark_closed()
+            raise
+
     async def __bind_execute(self, args, limit, timeout):
         protocol = self._connection._protocol
         try:

tests/test_prepare.py

@@ -600,3 +600,38 @@ async def test_prepare_does_not_use_cache(self):
         # prepare with disabled cache
         await self.con.prepare('select 1')
         self.assertEqual(len(cache), 0)
+
+    async def test_prepare_executemany(self):
+        await self.con.execute('CREATE TEMP TABLE exmany (a text, b int)')
+
+        try:
+            stmt = await self.con.prepare('''
+                INSERT INTO exmany VALUES($1, $2)
+            ''')
+
+            result = await stmt.executemany([
+                ('a', 1), ('b', 2), ('c', 3), ('d', 4)
+            ])
+
+            self.assertIsNone(result)
+
+            result = await self.con.fetch('''
+                SELECT * FROM exmany
+            ''')
+
+            self.assertEqual(result, [
+                ('a', 1), ('b', 2), ('c', 3), ('d', 4)
+            ])
+
+            # Empty set
+            await stmt.executemany(())
+
+            result = await self.con.fetch('''
+                SELECT * FROM exmany
+            ''')
+
+            self.assertEqual(result, [
+                ('a', 1), ('b', 2), ('c', 3), ('d', 4)
+            ])
+        finally:
+            await self.con.execute('DROP TABLE exmany')