表A
Km    dm
采油一矿    1队
采油一矿    2队
采油二矿    3队
采油二矿    4队
采油三矿    5队
采油三矿    6队
采油四矿    7队
采油四矿    8队
表B
Km    Dm    Rq    lrsj
采油一矿    1队    2006-8-4    2006-8-4 9:36:37 
采油二矿    3队    2006-8-4    2006-8-4 9:36:37
采油三矿    5队    2006-8-4    2006-8-4 9:36:37
采油四矿    7队    2006-8-4    2006-8-4 9:36:37
采油一矿    1队    2006-8-3    2006-8-3 9:36:37
采油一矿    2队    2006-8-3    2006-8-3 9:36:37
采油二矿    3队    2006-8-3    2006-8-3 9:36:37
采油二矿    4队    2006-8-3    2006-8-3 9:36:37
采油三矿    5队    2006-8-3    2006-8-3 9:36:37
采油三矿    6队    2006-8-3    2006-8-3 9:36:37
采油四矿    7队    2006-8-3    2006-8-3 9:36:37
采油四矿    8队    2006-8-3    2006-8-3 9:36:37
            
其中表A数据不变 ，表B每天有新数据
要得到的表C
Km    Dm    Rq    lrsj
采油一矿    1队    2006-8-4    2006-8-4 9:36:37 
采油一矿    2队    2006-8-4    暂无数据
采油二矿    3队    2006-8-4    2006-8-4 9:36:37
采油二矿    4队    2006-8-4    暂无数据
采油三矿    5队    2006-8-4    2006-8-4 9:36:37
采油三矿    6队    2006-8-4    暂无数据
采油四矿    7队    2006-8-4    2006-8-4 9:36:37
采油四矿    8队    2006-8-4    暂无数据
采油一矿    1队    2006-8-3    2006-8-3 9:36:37
采油一矿    2队    2006-8-3    2006-8-3 9:36:37
采油二矿    3队    2006-8-3    2006-8-3 9:36:37
采油二矿    4队    2006-8-3    2006-8-3 9:36:37
采油三矿    5队    2006-8-3    2006-8-3 9:36:37
采油三矿    6队    2006-8-3    2006-8-3 9:36:37
采油四矿    7队    2006-8-3    2006-8-3 9:36:37
采油四矿    8队    2006-8-3    2006-8-3 9:36:37

现在我只得到了如下表
Km    Dm    Rq    lrsj
采油一矿    1队    2006-8-4    2006-8-4 9:36:37 
采油二矿    3队    2006-8-4    2006-8-4 9:36:37
采油三矿    5队    2006-8-4    2006-8-4 9:36:37
采油四矿    7队    2006-8-4    2006-8-4 9:36:37
采油一矿    1队    2006-8-3    2006-8-3 9:36:37
采油一矿    2队    2006-8-3    2006-8-3 9:36:37
采油二矿    3队    2006-8-3    2006-8-3 9:36:37
采油二矿    4队    2006-8-3    2006-8-3 9:36:37
采油三矿    5队    2006-8-3    2006-8-3 9:36:37
采油三矿    6队    2006-8-3    2006-8-3 9:36:37
采油四矿    7队    2006-8-3    2006-8-3 9:36:37
采油四矿    8队    2006-8-3    2006-8-3 9:36:37

那些暂无数据的该怎么取得？请大家不吝赐教！谢谢！！