> Alan McDonald wrote:
> >>Is it possible to fire an event off when the DepartmentId changes?
> >>
> > before update trigger
> > if new.departmentid<>old.department.id then post_event blabla
>
> OK, thanks.
> Is it possible to get only some clients to register interest in only
> some users,

yes - you decide the trigger for clients to register and unregister

>or do *all* clients have to be told whenever anyone's
> department.id changes?

all clients with registered interest in the event will be notified at the
time the event fires. Aggain, it's up to you (application code) to decide
what actions to take when the client app receives the event notification.
(including ignore it)
Alan

>
> Richard
>