create or replace trigger preventdeleted502
before delete on d502_mzdetail
for each row
begin
if deleting then raise_application_error(-200001,'不允許刪除數(shù)據(jù)!');
dbms_output.PUT_LINE('不允許刪除數(shù)據(jù)!');
end if;
end;
解釋說(shuō)明：preventdeleted502為該觸發(fā)器名稱，d502_mzdetail為表名，對(duì)于表d502_mzdetail如果一有刪除動(dòng)作，馬上提示溢出錯(cuò)誤，同時(shí)打印錯(cuò)誤信息，那么刪除動(dòng)作即刻停止！