如何在MySQL中从出生日期计算年龄？

mysql> SET @dob = '1984-01-17';
Query OK, 0 rows affected (0.00 sec)

mysql> Select Date_format( From_Days( To_Days(Curdate()) - To_Days(@dob) ), '%Y' ) + 0 AS ‘Age in years;
+---------------+
| ‘Age in years’|
+---------------+
|   33          |
+---------------+
1 row in set (0.00 sec)