An UpdateObject builds a SQL UPDATE statment. It is passed around through the InputObjects who each set what they need to.

set( key, value)
for integers

setText(key, value)
strings will be escaped and surrounded with ' '

setTextFromPost( key, value)
if magic quotes is on or off, it will adapt and wrap it with ' '

It has an identical interface to InsertObject which means that Objekts and InputObjects don't need to care if they are inserting or updating, they just set()