Comment appliquer la fonction EXTRACT() aux dates stockées dans la table MySQL ?

mysql> Select * from testing;
+-------------+---------------------+
| StudentName | Dateofreg           |
+-------------+---------------------+
| Ram         | 2017-10-28 21:24:24 |
| Shyam       | 2017-10-28 21:24:30 |
| Mohan       | 2017-10-28 21:24:47 |
| Gaurav      | 2017-10-29 08:48:33 |
+-------------+---------------------+
4 rows in set (0.00 sec)

mysql> Select EXTRACT(Year from dateofreg)AS YEAR from testing;
+------+
| YEAR |
+------+
| 2017 |
| 2017 |
| 2017 |
| 2017 |
+------+
4 rows in set (0.00 sec)

mysql> Select EXTRACT(day from dateofreg)AS DAY from testing;
+-----+
| DAY |
+-----+
| 28  |
| 28  |
| 28  |
| 29  |
+-----+
4 rows in set (0.00 sec)