CREATE OR REPLACE TRIGGER TR_MEM_MEMBER_LOG
  AFTER INSERT OR UPDATE OR DELETE ON MEM_MEMBER
  FOR EACH ROW
DECLARE
  CURSOR CUR_MEM_MEMBER_LOG_DATA IS
    SELECT COLUMN_NAME, COLUMN_ID
      FROM USER_TAB_COLS
     WHERE TABLE_NAME = 'MEM_MEMBER'
     ORDER BY COLUMN_ID;
  V_COLUMN_NAME USER_TAB_COLS.COLUMN_NAME%TYPE;
  V_COLUMN_ID   USER_TAB_COLS.COLUMN_ID%TYPE;
  
  V_N_COLUMN_NAME_VALUE VARCHAR2(200);
  V_O_COLUMN_NAME_VALUE VARCHAR2(200);
BEGIN
  --更新时写日志
  IF UPDATING THEN
    OPEN CUR_MEM_MEMBER_LOG_DATA;
    LOOP
      FETCH CUR_MEM_MEMBER_LOG_DATA
        INTO V_COLUMN_NAME, V_COLUMN_ID;
      EXIT WHEN CUR_MEM_MEMBER_LOG_DATA%NOTFOUND;
      --有问题
      --改成下面这样，但是需要注意表中的数据类型，最好在这个位置增加一个数据类型的判断
      --如果是普通类型的没问题，varchar(200)可以，但是如果是日期类型的需要一个to_char函数转换
      EXECUTE IMMEDIATE 'SELECT :NEW.'|| V_COLUMN_NAME||',:OLD.'||V_COLUMN_NAME||' FROM DUAL'
                   INTO V_N_COLUMN_NAME_VALUE,V_O_COLUMN_NAME_VALUE;
      
      IF V_N_COLUMN_NAME_VALUE <> V_O_COLUMN_NAME_VALUE THEN
        INSERT INTO MEM_MEMBER_LOG
          (MEMBER_LOG_ID,
           MEMBER_ID,
           MENMBER_FIELDS,
           MENMBER_COUNT,
           MEMBER_LOG_FLAG,
           OPERATION_DATE)
        VALUES
          (SEQ_MEM_MEMBER_LOG.NEXTVAL,
           :OLD.MEMBER_ID,
           V_COLUMN_NAME,
           ':OLD.' || V_COLUMN_NAME,
           '2',
           SYSDATE);
      END IF;
    END LOOP;
    CLOSE CUR_MEM_MEMBER_LOG_DATA;
  END IF;
END TR_MEM_MEMBER_LOG;

------解决方案--------------------
自己说明下，这里这么写有问题，犯了经验主义错误。
SQL code

--写了个脚本生成主要部分的代码，楼主还是一个一个写吧。
DECLARE
  CURSOR CUR_MEM_MEMBER_LOG_DATA IS
    SELECT COLUMN_NAME, COLUMN_ID
      FROM USER_TAB_COLS
     WHERE TABLE_NAME = 'MEM_MEMBER'
     ORDER BY COLUMN_ID;
  V_COLUMN_NAME USER_TAB_COLS.COLUMN_NAME%TYPE;
  V_COLUMN_ID   USER_TAB_COLS.COLUMN_ID%TYPE;
  V_STRSQL LONG;
BEGIN
  OPEN CUR_MEM_MEMBER_LOG_DATA;
  LOOP
    FETCH CUR_MEM_MEMBER_LOG_DATA
      INTO V_COLUMN_NAME, V_COLUMN_ID;
    EXIT WHEN CUR_MEM_MEMBER_LOG_DATA%NOTFOUND;

      V_STRSQL :=V_STRSQL||'
      IF UPDATING('''||V_COLUMN_NAME||''') THEN '||
        'INSERT INTO MEM_MEMBER_LOG '||
          '(MEMBER_LOG_ID, '||
          ' MEMBER_ID, '||
          '