Query question

[EagleNick]

I am looking to change the subscription method of all threads for a single user.
In other words, change their subscriptions from "Instant E-mail Notification" to "No E-mail Notification".

Would this query do the trick?

UPDATE user SET autosubscribe = 0; WHERE userid = 'X';

And if that is a working query, I'm assuming it could also be used for a usergroup:

UPDATE user SET autosubscribe = 0; WHERE usergroupid = 'X';