After I upgrade from UBBT6 to UBBT7 , My (administrator) PM box is full of 'Welcome' message which are automatically sent to users.
This cause my PM's box has 2200+ pages (20 message / page).

I want to delete all of these PMs with the same Subject 'Welcome' .
What SQL command should I write ?

Here is my table :
Code
| ubbt_PRIVATE_MESSAGE_POSTS   |
| ubbt_PRIVATE_MESSAGE_TOPICS  |
| ubbt_PRIVATE_MESSAGE_USERS   |

Code
mysql> select count(*) from ubbt_PRIVATE_MESSAGE_TOPICS where TOPIC_SUBJECT = 'Welcome';

+----------+
| count(*) |
+----------+
|    31330 |
+----------+
1 row in set (0.17 sec)

English is not my native language. I try my best to express my thought precisely. I hope you understand what I mean. If any misunderstanding results from culture gaps, I apologize first.