mysql> SELECT '1988-08-14 00:00:00' + INTERVAL 30 YEAR + INTERVAL (SELECT DATEDI
FF('1987-08-14 00:00:00', '1987-08-31 00:00:00') AS 'Age Diff(days)') DAY as Dat
e;
+---------------------+
| Date                |
+---------------------+
| 2018-07-28 00:00:00 |
+---------------------+
1 row in set (0.02 sec)

mysql>