需要知道如何添加相应字段中缺少空数据的日期
**05/28/2012 NULL
05/29/2012 NULL
05/30/2012 NULL
05/30/2012 Break In
05/30/2012 Break Out
05/31/2012 NULL**
06/03/2012 NULL
06/03/2012 Break In
06/03/2012 Break Out
06/03/2012 In Duty
06/03/2012 Out Duty
06/04/2012 NULL
06/04/2012 In Duty
06/04/2012 Out Duty
06/05/2012 NULL
06/05/2012 Break In
06/05/2012 Break Out
06/06/2012 NULL
06/06/2012 Break In
06/06/2012 Break Out
06/06/2012 In Duty
06/06/2012 Out Duty
06/07/2012 NULL
06/07/2012 In Duty
06/07/2012 Out Duty
06/10/2012 NULL
06/10/2012 Break Out
06/10/2012 In Duty
06/10/2012 Out Duty
06/11/2012 NULL …