请教：如何按时间段统计

Question

表结构如下
表A
------------------------------
区域          时间           数量
N             2009-10-1       3
N             2009-10-2       3
N             2009-10-3       3
N             2009-10-4       3
N             2009-10-5       3
Y             2009-10-6       3
Y             2009-10-7       3
Y             2009-10-8       3
Y             2009-10-9       3
Y             2009-10-2       3
Y             2009-10-4       3
......得到如下结构：--------------------------------
 区域           时间段T      数量
                 t=1天         5
 总计          2>=t>1天        5
               3>=t>2天        5
               3<t天           5
       -------------------------
                 t=1天         5
  N            2>=t>1天        5
               3>=t>2天        5
               3<t天           5
    ----------------------------
                 t=1天         5
  Y            2>=t>1天        5
               3>=t>2天        5
               3<t天           5
多谢

Answer 1

case when  union all

Answer 2

得到如下结构：--------------------------------
 区域   时间段T     数量
           t=1天    5
 总计  2>=t>1天     5
      3>=t>2天     5
         3<t天     5
  -------------------------
          t=1天    5
  N      2>=t>1天  5
          3>=t>2天 5
            3<t天  5
  ----------------------------
            t=1天   5
  Y        2>=t>1天 5
           3>=t>2天 5
             3<t天  5

Answer 3

表结构如下
表A
------------------------------
区域          时间           数量
N             2009-10-1       3
N             2009-10-2       3
N             2009-10-3       3
N             2009-10-4       3
N             2009-10-5       3
Y             2009-10-6       3
Y             2009-10-7       3
Y             2009-10-8       3
Y             2009-10-9       3
Y             2009-10-2       3
Y             2009-10-4       3
......得到如下结构：--------------------------------
 区域           时间段T       数量
                 t=1天            5
 总计          2>=t>1天           5
               3>=t>2天         5
               3<t天            5
       -------------------------
                 t=1天         5
  N            2>=t>1天        5
               3>=t>2天        5
               3<t天           5
    ----------------------------
                 t=1天         5
  Y            2>=t>1天        5
               3>=t>2天        5
               3<t天            5