ORA-04091: table 正在变异，trigger/function 在执行 oracle 触发器期间可能看不到它错误

Question

我有下面的触发器，其中 FIELD_NAME 字段我想将值插入 FIELD_TRACKING table 作为 'Deactivation time of KPI in case of Downtime(Select KPI_FREQ_TIME_UNIT FROM KPI_DEFINITION)'。此字符串值中的括号部分来自 KPI_DEFINITION table 的 KPI_FREQ_TIME_UNIT 字段。所以下面是我为此写的触发器。触发器编译没有任何错误。但是，当我尝试从 KPI_DEFINITION table 更改 DNTM_REAC_AFTER_HRS 字段时，出现错误 ORA-04091: table RATOR_MONITORING_CONFIGURATION.KPI_DEFINITION is mutating, trigger/function may not see it ORA-04088: error during execution of trigger 'RATOR_MONITORING_CONFIGURATION.TRG_TRK_KPI_DEFINITION'.

create or replace TRIGGER RATOR_MONITORING_CONFIGURATION."TRG_TRK_KPI_DEFINITION" AFTER UPDATE ON RATOR_MONITORING_CONFIGURATION.KPI_DEFINITION
      FOR EACH ROW

    IF NOT  :old.DNTM_REAC_AFTER_HRS=:new.DNTM_REAC_AFTER_HRS THEN
        INSERT INTO RATOR_MONITORING_CONFIGURATION.FIELD_TRACKING  (FIELD_TRACKING_ID,TABLE_NAME,TABLE_ID, FIELD_NAME,FIELD_OLD_VALUE,FIELD_NEW_VALUE,USER_ID, TIMESTAMP, FIELD_TRACKING_COMMENTS)
        VALUES (FIELD_TRACKING_SEQ.NEXTVAL,'KPI_DEFINITION',:new.KPI_DEF_ID,'Deactivation time of KPI in case of Downtime'|| '(' || to_char((Select KPI_FREQ_TIME_UNIT FROM KPI_DEFINITION)) || ')',to_char(:old.DNTM_REAC_AFTER_HRS),to_char( :new.DNTM_REAC_AFTER_HRS),:new.LAST_UPDATED_BY,:new.LAST_UPDATED_DATE, decode(:new.KPI_ACTIVE_DOWNTIME,'N','This KPI has been reactivated on end of a downtime.',''));
      END IF;

    END;

Answer 1

触发器无法读取 table（Select KPI_FREQ_TIME_UNIT FROM KPI_DEFINITION），更改...您可以通过这种方式访问值：:new.KPI_FREQ_TIME_UNIT。更多信息：http://www.dba-oracle.com/t_avoiding_mutating_table_error.htm

其他情况可以尝试在autonomous transaction:

create or replace TRIGGER RATOR_MONITORING_CONFIGURATION."TRG_TRK_KPI_DEFINITION" 
AFTER UPDATE ON RATOR_MONITORING_CONFIGURATION.KPI_DEFINITION FOR EACH ROW
DECLARE
   PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
  -- ...
  COMMIT; -- don't forget it!!!
END;

Answer 2

由于您需要来自 table 的信息，您为其创建了触发器（Select KPI_FREQ_TIME_UNIT FROM KPI_DEFINITION），您可以获得 KPI_FREQ_TIME_UNIT 来自参考 :NEW 因为它代表新行 (:NEW.KPI_FREQ_TIME_UNIT).

ORA-04091: table 正在变异，trigger/function 在执行 oracle 触发器期间可能看不到它错误

ORA-04091: table is mutating, trigger/function may not see it error during execution of oracle trigger

oracle

triggers

sql-insert