Defining trigger conditions for events

Each event definition has a system event associated with it. It also has one or more trigger conditions. The event handler is triggered when the trigger conditions for the system event are satisfied.

The trigger conditions associated with Sybase IQ events are not the same as SQL Anywhere or Adaptive Server Enterprise triggers, which execute automatically when a user attempts a specified data modification statement on a specified table.

See ”Defining trigger conditions for events” in SQL Anywhere Server - SQL Usage.

Sybase IQ example

For examples, use the Sybase IQ demo database iqdemo.db. For installation information, see “The demo database”.

create event SecurityCheck
type ConnectFailed
handler
begindeclare num_failures int;declare mins int;

insert into FailedConnections( log_time )values ( current timestamp );
select count( * ) into num_failuresfrom FailedConnectionswhere log_time >= dateadd( minute, -5, 
	current timestamp );if( num_failures >= 3 ) then
	select datediff( minute, last_notification,		current timestamp ) into mins	from Notification;
	if( mins > 30 ) then		update Notification		set last_notification = current timestamp;		call xp_sendmail( recipient='DBAdmin',				subject='Security Check',"message"=		'over 3 failed connections in last 5 minutes' )	end ifend ifend