Add Cursor.fetchval method (#433)

* Added ``Cursor.fetchval`` method

* Added test for ``Cursor.fetchval``

---------

Co-authored-by: Haruka3399 <57554044+Saratoga-CV6@users.noreply.github.com>

aioodbc/cursor.py

@@ -163,6 +163,16 @@ def fetchone(self):
         fut = self._run_operation(self._impl.fetchone)
         return fut
 
+    def fetchval(self):
+        """Returns the first column of the first row if there are results.
+
+        A ProgrammingError exception is raised if no SQL has been executed
+        or if it did not return a result set (e.g. was not a SELECT
+        statement).
+        """
+        fut = self._run_operation(self._impl.fetchval)
+        return fut
+
     def fetchall(self):
         """Returns a list of all remaining rows.
 

tests/test_cursor.py

@@ -172,6 +172,18 @@ async def test_fetchone(conn, table):
     await cur.close()
 
 
+@pytest.mark.parametrize("db", pytest.db_list)
+@pytest.mark.asyncio
+async def test_fetchval(conn, table):
+    cur = await conn.cursor()
+    await cur.execute("SELECT * FROM t1;")
+    resp = await cur.fetchval()
+    expected = 1
+
+    assert expected == resp
+    await cur.close()
+
+
 @pytest.mark.parametrize("db", ["sqlite"])
 @pytest.mark.asyncio
 async def test_tables(conn, table):