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?
[解决办法]
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)