select (SELECT count(*)
        from hacconf.resource,hacconf.auditor_session_author,hacref.session 
        where starttime>=1346169600 and starttime<=1346255999 
        and hacref.session.appname=hacconf.resource.name 
        and hacconf.resource.dev_id=hacconf.auditor_session_author.dev_id 
        and hacconf.auditor_session_author.manager_id=3 and endtime > 1) 
    + 
        (SELECT count(*) from hacref.session 
        where starttime>=1346169600 and starttime<=1346255999 and endtime = 1)) as sum
--or
select sum(t.[sum]) as sum from 
(
    SELECT count(*) as sum
    from hacconf.resource,hacconf.auditor_session_author,hacref.session 
    where starttime>=1346169600 and starttime<=1346255999 
    and hacref.session.appname=hacconf.resource.name 
    and hacconf.resource.dev_id=hacconf.auditor_session_author.dev_id 
    and hacconf.auditor_session_author.manager_id=3 and endtime > 1
    union all
    SELECT count(*) from hacref.session 
    where starttime>=1346169600 and starttime<=1346255999 and endtime = 1
)t