oracle 触发器及游标的使用

create or replace trigger tri_salary
   after insert on salary  
   for each row
declare
   id varchar2(8);
   name varchar2(8);
   salary number(8);
   cursor cur is select seq_salary.nextval as seq from dual;
   cursor log is select salary from salary_log where salary_log.name = name;
   mylog log%rowtype;
   myseq   cur%rowtype;
begin
   id:= :new.id;
   name:= :new.name;
   salary:= :new.salayry;
   open cur;
   open log;
   fetch cur into myseq;
   if log%notfound then
   insert into salary_log values(myseq.seq,id,name,salary);
   else
   fetch log into mylog;
   insert into salary_log values(myseq.seq,id,name,mylog.salary);
   end if;
  
   close log;
   close cur;
end ;