中科新闻网电除尘器结构图:请问这个触发器脚本有什么语法错误！
来源：百度文库 编辑：中科新闻网 时间：2024/05/15 02:23:55
create or replace trigger Attach_trig_autoinc
before insert on Attachment
for each row
begin
if (:new.AttachID is null) then
select Attachment_seq.nextval into :new.AttachID from dual;
end if;
end;
before insert on Attachment
for each row
begin
if (:new.AttachID is null) then
select Attachment_seq.nextval into :new.AttachID from dual;
end if;
end;
我知道