Zabbix sql queries

delete from items where hostid=(select hostid from hosts where host='www.example.com');
delete from items where hostid=(select hostid from hosts where host='www.example.com') and itemid!=252623 and itemid!=253055;

Not sure if work

SELECT DISTINCT host, f.triggerid, e.acknowledged, priority 
FROM triggers t 
INNER JOIN functions f ON ( f.triggerid = t.triggerid ) 
INNER JOIN items i ON ( i.itemid = f.itemid ) 
INNER JOIN hosts ON ( i.hostid = hosts.hostid ) 
INNER JOIN events e ON ( e.objectid = t.triggerid ) 
WHERE (e.eventid / 100000000000000) 
IN (0) 
AND e.object = 0 
AND t.value=1 
AND hosts.status = 0 
AND i.status = 0 
AND t.status = 0 
AND e.acknowledged = 0 
AND e.clock > (SELECT DISTINCT max(e.clock) 
FROM triggers t 
INNER JOIN functions f ON ( f.triggerid = t.triggerid ) 
INNER JOIN items i ON ( i.itemid = f.itemid ) 
INNER JOIN hosts ON ( i.hostid = hosts.hostid ) 
INNER JOIN events e ON ( e.objectid = t.triggerid ) 
WHERE (e.eventid / 100000000000000) 
IN (0) 
AND e.object = 0 
AND t.value=1 
AND hosts.status = 0 
AND i.status = 0 
AND t.status = 0 
AND e.acknowledged = 1 
)
LIMIT 1;