自定义函数实现字符串中数据的运算和统计2

上一篇是汇总操作，这一篇是求平均值,并且数据可能出现非数字和负数

问题:
数据表如下

cate values dates
A1 12.32,15.6,14.5,45.00,78.12,23.45 2006-04-01
A2 14.56,67.23,45.12,23.1,34.67,56.98 2006-04-01
A1 12.31,15.6,14.5,44.00,78.12,23.45 2006-04-01
A2 14.56,67.23,45.12,23.1,34.67,56.98 2006-04-01
A1 12.32,15.6,14.5,45.00,78.12,23.45 2006-05-01
A2 14.56,67.23,45.12,23.1,34.67,56.98 2006-05-01
A1 12.31,15.6,14.5,44.00,78.12,23.45 2006-05-01
A2 14.56,67.23,45.12,23.1,34.67,56.98 2006-05-01
A1 -12.32,15.6,14.5,45.00,78.12,23.45 2006-04-01
A2 12.32,-15.6,14.5,无,78.12,23.45 　 2006-04-01
不用存储过程实现如下数据统计
cate T1 dates
A1 4.10333,15.6,14.5,44.6667,78.12,23.45 2006-04-01
A1 12.315,15.6,14.5,44.5,78.12,23.45 2006-05-01
A2 13.8133,39.62,34.9133,15.4,49.1533,45.8033 2006-04-01
A2 14.56,67.23,45.12,23.1,34.67,56.98 2006-05-01
==========================================================================
就是 values 值之间用,隔开的,当cate和dates 相同时,算values中各个以,隔开的数值的平均值,要求是不用存储过程实现

实现：

--建立环境

create table up(
cate varchar(3),
[values] varchar(50),
dates datetime
)

insert up select
'A1','12.32,15.6,14.5,45.00,78.12,23.45','2006-04-01'
union all select
'A2','14.56,67.23,45.12,23.1,34.67,56.98','2006-04-01'
union all select
'A1','12.31,15.6,14.5,44.00,78.12,23.45','2006-04-01'
union all select
'A2','14.56,67.23,45.12,23.1,34.67,56.98','2006-04-01'
union all select
'A1','12.32,15.6,14.5,45.00,78.12,23.45','2006-05-01'
union all select
'A2','14.56,67.23,45.12,23.1,34.67,56.98','2006-05-01'
union all select
'A1','12.31,15.6,14.5,44.00,78.12,23.45','2006-05-01'
union all select
'A2','14.56,67.23,45.12,23.1,34.67,56.98','2006-05-01'
union all select
'A1','-12.32,15.6,14.5,45.00,78.12,23.45','2006-04-01'
union all select
'A2','12.32,-15.6,14.5,无,78.12,23.45','2006-04-01'

go

--求平均值函数
create function fn_ValuesAvg(
@cate varchar(3),
@dates datetime
)
returns varchar(50)
as
begin
declare @r varchar(50)
set @r=''
declare @t table (
[values] varchar(50)
)
insert @t select [values] from up where cate=@cate and dates=@dates

declare @t1 table (
No int,
[values] float
)
declare @No int

set @No=1
while exists (select 1 from @t where charindex(',',[values])>0)
begin
insert @t1 select @No,
case when isnumeric(left([values],charindex(',',[values])-1))=1 then cast(left([values],charindex(',',[values])-1) as float) else 0 end
from @t

update @t set [values]=stuff([values],1,charindex(',',[values]),'')
set @No=@No+1
end
insert @t1 select @No,case when isnumeric([values])=1 then cast([values] as float) else 0 end from @t

select @r=@r+','+cast(avg([Values]) as varchar) from @t1 group by No order by No

return stuff(@r,1,1,'')
end
go

--查询
select cate,dbo.fn_valuesavg(cate,dates) as T,dates
from up
group by cate,dates

--结果

cate T dates
---- -------------------------------------------------- ------------------------------------------------------
A1 4.10333,15.6,14.5,44.6667,78.12,23.45 2006-04-01 00:00:00.000
A1 12.315,15.6,14.5,44.5,78.12,23.45 2006-05-01 00:00:00.000
A2 13.8133,39.62,34.9133,15.4,49.1533,45.8033 2006-04-01 00:00:00.000
A2 14.56,67.23,45.12,23.1,34.67,56.98 2006-05-01 00:00:00.000

（所影响的行数为 4 行）