gistfile1.sql

mysql> select prop_value from participant_data where participant_id = 1394 and prop_key = 'core_2_preferred_bedtime';
+------------+
| prop_value |
+------------+
| 4:00 am    |
+------------+
1 row in set (0.04 sec)

mysql> start transaction;
Query OK, 0 rows affected (0.00 sec)

mysql> update participant_data set prop_value = '1:00 am' where participant_id = 1394 and prop_key = 'core_2_preferred_bedtime';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> commit;
Query OK, 0 rows affected (0.01 sec)