gistfile1.txt

mysql> select count(*) from radacct where TimeStop is NULL;
+----------+
| count(*) |
+----------+
|    47318 |
+----------+
1 row in set (0.04 sec)

mysql> select distinct username from radacct where TimeStop is NULL;
...
| bromo                    |
| argopuro                 |
| arjuno                   |
+--------------------------+
39 rows in set (0.98 sec)

mysql> update radacct set TimeStop=NOW() where TimeStop is NULL;
Query OK, 0 rows affected (0.00 sec)