多列更新时如何触发

Question

在这里，如果任何一列被更新，我想触发更新查询。但我收到错误表表正在发生变化，触发器/函数可能看不到它。

create or replace
  TRIGGER TRIGGER1 
    AFTER  UPDATE OF HOST_ID,ENABLED_FLAG,ACTIVE_FLAG,AGENT_COUNTER,USER_WAIT_FLAG ON  MONITOR_AGENT_STATUS 
  FOR EACH ROW
    BEGIN
update monitor_agent_status set active_flag='Y', enabled_flag='Y', agent_counter=0, user_flag='N';
 END;

Answer 1

您应该在 BEFORE 行触发器中设置如下值：

create or replace
  TRIGGER TRIGGER1 
    BEFORE UPDATE OF HOST_ID,ENABLED_FLAG,ACTIVE_FLAG,AGENT_COUNTER,USER_WAIT_FLAG ON  MONITOR_AGENT_STATUS 
  FOR EACH ROW
    BEGIN
      :NEW.active_flag:='Y';
      :NEW.enabled_flag:='Y';
      :NEW.agent_counter:=0;
      :NEW.user_flag:='N';
 END;

你的第二个触发点（来自下面的评论）：

CREATE OR REPLACE TRIGGER TRIGGER11 
BEFORE UPDATE OF HOST_ID ON HOST_CURR_TIME 
FOR EACH ROW 
DECLARE 
   NewHost_Time varchar(10); 
BEGIN 
   select HOST_ID 
   into   NewHost_Time 
   from   HOST_CURR_TIME 
   where  HOST_ID='ATLMB100'; 

   :new.HOST_ID:= case :new.HOST_ID 
                     when 'CCNAFE02' then NewHost_Time 
                     when 'OFCBSERV' then NewHost_Time 
                     else :new.HOST_ID 
                  end; 
END;