触发器问题.在线等!

Question

begin
select project_id,project_level,project_grade1_id,project_grade2_id
    into project_id1,project_level1,project_grade1_id1,project_grade2_id1
    from t_project
   where project_name=proart1;
exception
when no_data_found then
  null;
end;為什麼不用用异常啊？

Answer 1

如果project_id是主键，可以考虑使用如下方式
select nvl(max(project_id),'is null'),max(project_level),max(project_grade1_id),max(project_grade2_id)
    into project_id1,project_level1,project_grade1_id1,project_grade2_id1
    from t_project
   where project_name=proart1;if project_id1 = 'is null' then
   ...
else
   ...
end if;