ID EMAIL EFF_DT EXP_DT
486007909 ? 7/22/2009 7/22/2009
486007909 ? 7/23/2009 7/23/2009
486007909 [email protected] 7/24/2009 8/2/2009
486007909 [email protected] 8/3/2009 8/10/2009
486007909 [email protected] 8/11/2009 9/6/2013
486007909 ? 9/7/2013 10/22/2014
486007909 ? 10/23/2014 11/3/2014
486007909 [email protected] 11/4/2014 12/1/2016
我正在从历史记录表中提取列的子集(已生效),但需要进行压缩,因此仅显示对相关值的更改。我需要压缩,因为历史记录表...