如何统计每一列中各项的个数？
我有一张统计表keguan结构如下
st1         st2         st3         st4     .......
  a             b             c             d       .......
  b             a             d             a       .......
  d             c             c             c       .......

我想统计   st1中a有几个，b有几个，c有几个，d有几个，st2中a有几个，b有几个，c有几个，d有几个，..........，请问这个sql语句该怎么写？

------解决方案--------------------
create table T
(
st1 varchar(10),
st2 varchar(10),
st3 varchar(10),
st4 varchar(10)
)

insert T select 'a ', 'b ', 'c ', 'd '
insert T select 'b ', 'a ', 'd ', 'a '
insert T select 'd ', 'c ', 'c ', 'c '

declare @T_SQL varchar(8000)
set @T_SQL= ' '
select @T_SQL=@T_SQL + 'select ' ' ' + a.name + ' ' ' as F_Name, ' + a.name + ' from T union all '
from syscolumns a,sysobjects d
where a.id=d.id
and d.name= 'T '

set @T_SQL=left(@T_SQL,len(@T_SQL)-len( ' union all '))
set @T_SQL= 'select F_Name,st1,count(1) as number from ( ' + @T_SQL + ' ) T group by F_Name,st1 order by F_Name '
exec (@T_SQL)