對不起我的英語不好。我有2張桌子：Table1idtable2_idnummodification_date 和Table2idtable2num我想打一個觸發(fā)器，它插入或刪除操作后在Table1更新的最后一個值num的Table2.table1lastnum。我的觸發(fā)器：CREATE OR REPLACE TRIGGER TABLE1_NUM_TRG  AFTER INSERT OR DELETE ON table1  FOR EACH ROWBEGIN  IF INSERTING then  UPDATE table2  SET    table2num = :new.num  WHERE  table2.id = :new.table2_id;  ELSE  UPDATE table2  SET    table2num = (SELECT num FROM  (SELECT num FROM table1 WHERE table2_id = :old.table2_id ORDER BY modification_date DESC) WHERE ROWNUM <= 1)  WHERE  table2.id = :old.table2_id;  END IF;END TABLE1_NUM_TRG; 但刪除后Table1我有錯誤：ORA-04091: table BD.TABLE1 is mutating, trigger/function may not see itORA-06512: at "BD.TABLE1_NUM_TRG", line 11ORA-04088: error during execution of trigger 'BD.TABLE1_NUM_TRG'我究竟做錯了什么？