apex_item示例选择列表

Question

目前，我正在同一地区处理3个顶点商品。

1. chckbox
2. selectlist
3. text area 

select apex_item.checkbox(3,ID) select_Checkbox,
       REQUESTED_WORDS,
       apex_item.textarea(10) as Comments,
       APEX_ITEM.SELECT_LIST_FROM_LOV(43,Null,'SELECT_LIST_LOV','%','NO') as Word_Status,
       REQUESTED_BY,
       REQUESTED_DATE
from xo_requests

创建了一个LoV并在这里使用它，我的问题是每次插入null值时都会在过程代码中插入已检查的记录的记录。

代码：

begin    
  FOR i in 1..APEX_APPLICATION.G_f06.COUNT LOOP
    apex_application.g_print_success_message :=APEX_APPLICATION.G_f48(i);

    select REQUESTED_WORDS, 
           REQUESTED_BY,
           ID 
      into l_words,
           l_requested_by,
           l_seq_id
      from XO_REQUESTS 
      where ID = APEX_APPLICATION.G_f06(i);

    update XO_REQUESTS set 
      REQUEST_STATUS = APEX_APPLICATION.G_f48(i),
      UPDATED_BY = :APP_USER,
      UPDATED_DATE = SYSDATE
      WHERE ID = l_seq_id 
       and REQUEST_TYPE = 'Add' ;

    insert into XO_REQUEST_HISTORY 
      (ID, REQUEST_ID, ACTION, 
       ACTION_TAKEN_BY, ACTION_TAKEN_DATE, COMMENTS)
    Values
    (XO_REQUEST_HISTORY_SEQ.NEXTVAL, l_seq_id, APEX_APPLICATION.G_f48(i),
     :APP_USER, SYSDATE, APEX_APPLICATION.G_f09(i));

  end loop;        
end;

为什么要在表中插入空值？

请检查我的代码，让我知道如何继续进行操作。

谢谢