帮我看下这个触发器是否正确
CREATE OR REPLACE TRIGGER TR_CUSTOMER_ORDER_WAFERSIZE
BEFORE INSERT ON wip_customer_order
FOR EACH ROW
declare wafer_sizeA varchar2(32);
BEGIN
select reserved1 into wafer_sizeA from MM_MATERIAL where name = :NEW.PART_NAME;
:NEW.wafer_SIZE : = wafer_sizeA ;
end;
想实现修改当前插入的某个字段的值,