看下这个TRIGGER什么问题

CREATE OR REPLACE TRIGGER EF_STANDARD_WORK_T
AFTER INSERT OR UPDATE ON EF_STANDARD_WORK_HOURS
REFERENCING NEW AS New OLD AS Old
FOR EACH ROW
WHEN (NEW.GROUP_ID IN (18,19,23,25,57))
DECLARE
models varchar(40);
Part_no INV_PN.PART_NO%TYPE;
counts1 number(2);
counts2 number(2);
standard_work_time number(8);
CURSOR C_partno;

BEGIN
if new.group_id in (18,19,23) then
select sum(standard_work_time) into standard_work_time from ef_standard_work_hours
where model=:new.model
and group_id in (18,19,23);

select nvl(count(*),0) into counts2 from inv_pn where model=:new.model and SUBSTR (part_no, 1, 2)='70';

if counts2>0 then
CURSOR C_partno is select part_no from inv_pn where model=:new.model and SUBSTR (part_no, 1, 2)='70';
OPEN c_partno;

LOOP