if-clause to an exiting statement

hi i am a newbie to sql statments  , I am running postgres 8.1 with
application called opennms version 1.8.5 due to an application bug
queries that I execute aginst the DB which returns raw-count=0 are being
ignored and will not process a certain trigger I need to process.

My question is :  Can I use an if-clause into my statement (see below)
which will check if the returned raw-count =0 then will return
raw-count=1 ?
----------------------------------------------------------------------------------
SELECT a.eventuei AS _eventuei,
                 a.nodeid AS _nodeid,
                 a.ipaddr AS _ipaddr,
                 now() AS _ts
            FROM events a
                WHERE
a.eventuei='uei.opennms.org/comns/backup-success-trap' AND
                (eventcreatetime > now() - interval '10 minutes')
----------------------------------------------------------------------------------

Thanks!