Oracle Apex：从表A中调用表A中的触发器

Question

我试图从表A中执行触发器操作，导致表B中的触发器操作，但出现以下错误。

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，当我从表中删除一个项目它会调用这个触发

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; 

这将最终删除另一条记录在另一个表，要求删除触发器在该表

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; 

我不明白是什么问题。

我该如何解决这个问题？

Answer 1

“问题是什么”

当你删除infra_assets_master你的桌子上触发器在subnet_lookup执行删除的子记录。但该表也有一个触发器，它查找其父项infra_assets_master记录。您正在删除的记录是。 Oracle不知道如何解决这个混淆问题，因此抛出了变异表错误。

“我该如何解决此问题？”

通过删除循环依赖关系。您需要更改业务逻辑以避免infra_assets_master上的查询。您的问题恰恰在于您的问题，因为这是您的业务逻辑不是我们的业务逻辑，但基本上您需要找到一种方法来填充历史记录表，仅使用正在删除的表中的信息填充历史记录表。备用将所有SUBNET_LOOKUP_DELETE_TRIGGER逻辑放入从INFRA_MASTER_DELETE_TRIGGER调用的存储过程中。