You can do a lot of that kind of thing with simple SQL.
Code:
UPDATE items SET damage = damage * 1.25 WHERE damage > 0
UPDATE items SET ac = ac * 2 WHERE ac > 0
UPDATE items SET hp = hp * 2 WHERE hp > 0
UPDATE items SET mana = mana * 2 WHERE mana > 0
UPDATE items SET classes = 65535 WHERE classes > 0
UPDATE items SET races = 65535 WHERE races > 0
UPDATE items SET deity = 0