MySQL | SELECT MAX(`HourEnding`) FROM - Rymo - m36b1f866

SELECT MAX(`HourEnding`) FROM `lmp_hourly` WHERE `RTStatus` = 'final';
#+---------------------+
#| MAX(`HourEnding`)   |
#+---------------------+
#| 2010-01-28 22:59:59 |
#+---------------------+
#1 row in set (0.00 sec)

SELECT MAX(`HourEnding`) FROM `lmp_hourly` WHERE `RTStatus` = 'prelim';
+---------------------+
| MAX(`HourEnding`)   |
+---------------------+
| 2010-01-30 22:59:59 |
+---------------------+
1 row in set (0.00 sec)

mysql> SELECT MAX(`he`) FROM ((SELECT MAX(`HourEnding`) `he` FROM `lmp_hourly` WHERE `RTStatus` = 'prelim') UNION (SELECT MAX(`HourEnding`) `he` FROM `lmp_hourly` WHERE `RTStatus` = 'final')) `t`;
+---------------------+
| MAX(`he`)           |
+---------------------+
| 2010-01-30 22:59:59 |
+---------------------+
1 row in set (0.00 sec)