Oracle触发器修改自身字段解决方案

--创建表结构
/*
CREATE TABLE TBL_USER(
  USER_ID INTEGER PRIMARY KEY,
  UNAME VARCHAR2(20) NOT NULL,
  UPWD VARCHAR2(20) NOT NULL,
  LAST_MODIFIED DATE
);*/
--1、创建程序包
CREATE OR REPLACE PACKAGE PKG_TBLUSER_UPDATE
AS
  G_ID TBL_USER.USER_ID%TYPE;
END PKG_TBLUSER_UPDATE;
/
--2、创建行触发器
CREATE OR REPLACE TRIGGER AFTER_UPD_TBLUSER_ROWTRG
AFTER UPDATE OF UNAME ON TBL_USER
FOR EACH ROW
BEGIN
  PKG_TBLUSER_UPDATE.G_ID:=:NEW.USER_ID;
END;
/
--3、创建语句触发器（根据程序包的全局变量，对数据表TBLUSER字段进行更新）
CREATE OR REPLACE TRIGGER AFTER_UPD__TBLUSER_TRG
AFTER UPDATE OF UNAME ON TBL_USER
BEGIN
  UPDATE TBL_USER 
    SET LAST_MODIFIED = SYSDATE 
    WHERE 
    USER_ID = PKG_TBLUSER_UPDATE.G_ID;
END;
/