Oracle Apex：從表A中調用表A中的觸發器

Question

我試圖從表A中執行觸發器操作，導致表B中的觸發器操作，但出現以下錯誤。

ORA-04091: table IMIT.INFRA_ASSETS_MASTER is mutating, trigger/function may not see it 
ORA-06512: at "IMIT.SUBNET_LOOKUP_DELETE_TRIGGER", line 15 
ORA-04088: error during execution of trigger 'IMIT.SUBNET_LOOKUP_DELETE_TRIGGER' 
ORA-06512: at "IMIT.INFRA_MASTER_DELETE_TRIGGER", line 2 
ORA-04088: error during execution of trigger 'IMIT.INFRA_MASTER_DELETE_TRIGGER' 

所以，當我從表中刪除一個項目它會調用這個觸發

CREATE OR REPLACE EDITIONABLE TRIGGER "INFRA_MASTER_DELETE_TRIGGER" 
    before delete on infra_assets_master 
    for each row 
begin 
    DELETE FROM SUBNET_LOOKUP WHERE LINK_ID = :old.ID AND DEF_ID = 3; 
    INSERT INTO HISTORY (IT_TABLE,ITEM_ID,ACTION_TYPE,ACTION)VALUES('INFRA_ASSETS_MASTER',:old.ID,3,CONCAT(CONCAT('Infrastructure Asset ', :old.ASSET_ID),' deleted')); 
end; 

這將最終刪除另一條記錄在另一個表，要求刪除觸發器在該表

CREATE OR REPLACE EDITIONABLE TRIGGER "SUBNET_LOOKUP_DELETE_TRIGGER" 
    before delete on subnet_lookup 
    for each row 
declare 
    v_def varchar2(255); 
    v_link varchar2(255); 
    v_subnet varchar2(255); 
    v_sen varchar2(255); 
begin 
    select NAME into v_def from subnet_lookup_definition where id = :old.DEF_ID; 
    v_sen := 'Remove Link Between '; 
    if :old.DEF_ID = 1 then 
     select hostname into v_link from servers_master where id = :old.LINK_ID; 
     v_sen := concat(v_sen,concat(concat('Server ''', v_link),'''')); 
    end if; 

    if :old.DEF_ID = 3 then 
     select asset_id into v_link from infra_assets_master where id = :old.LINK_ID; 
     if v_link IS NULL then 
     select hostname into v_link from infra_assets_master where id = :old.LINK_ID; 
     end if; 
     v_sen := concat(v_sen,concat(concat('Infrastructure Assets ''', v_link),'''')); 
    end if; 

    if :old.DEF_ID = 4 then 
     select asset_id into v_link from assets_master where id = :old.LINK_ID; 
     v_sen := concat(v_sen,concat(concat('IT Assets ''', v_link),'''')); 
    end if; 

    select address into v_subnet from subnet where id = :old.SUBNET_ID; 

    v_sen := concat(concat(v_sen, concat(' to ', v_subnet)),' has been deleted'); 

    insert into HISTORY (IT_TABLE, ITEM_ID,ACTION_TYPE, ACTION) VALUES ('SUBNET_LOOKUP',:old.SUBNET_ID,3,v_sen); 
end; 

我不明白是什麼問題。

我該如何解決這個問題？

Answer 1

「問題是什麼」

當你刪除infra_assets_master你的桌子上觸發器在subnet_lookup執行刪除的子記錄。但該表也有一個觸發器，它查找其父項infra_assets_master記錄。您正在刪除的記錄是。 Oracle不知道如何解決這個混淆問題，因此拋出了變異表錯誤。

「我該如何解決此問題？」

通過刪除循環依賴關係。您需要更改業務邏輯以避免infra_assets_master上的查詢。您的問題恰恰在於您的問題，因爲這是您的業務邏輯不是我們的業務邏輯，但基本上您需要找到一種方法來填充歷史記錄表，僅使用正在刪除的表中的信息填充歷史記錄表。備用將所有SUBNET_LOOKUP_DELETE_TRIGGER邏輯放入從INFRA_MASTER_DELETE_TRIGGER調用的存儲過程中。