PHP/MySql I need to UPDATE data in a table anywhere a string is found in the

[x_9th.gate_x]

table everytime the page loads...? Ok, so basically I'm replacing a string everytime the page loads. But I need an UPDATE script that can find the string anywhere in the DB.

Something like:

UPDATE forum SET 'blocked' WHERE * ='string';

????
No, I dont want to use a loop. Just want it to fix the DB once everytime the page loads.