愁死我了,（一个函数n参数）
我现在想做一个函数，比如：我想求n个数的和，n是一个不固定的数，这个函数就得写成sum(n1,n2,n3,…………)
怎么写这个函数

------解决方案--------------------
一表值函数
select sum(cast(col as int)) from pqs_split( '1,2,3,4,45,645,7567 ', ', ')

------解决方案--------------------
declare @s varchar(100)
declare @s1 varchar(100)
declare @i smallint
declare @len smallint
declare @sum smallint
set @sum=0
set @s1= ' '
set @s= '12,32,52,72,19, '
set @len=len(@s)
set @i=0
while @i <=@len
begin
if(substring(@s,@i,1)= ', ')
begin
set @sum=@sum+cast(@s1 as int)
set @s1= ' '
end
else
begin
set @s1=@s1+substring(@s,@i,1)
end
set @i=@i+1
end
print cast(@sum as int)

-------
187

你把這段語句放入函數中，其中，＠s為輸入參數

------解决方案--------------------
create function sum_data(@s varchar(100))
returns int
as
begin
--declare @s varchar(100)
declare @s1 varchar(100)
declare @i smallint
declare @len smallint
declare @sum smallint
set @sum=0
set @s1= ' '
--set @s= '12,32,52,72,19, '
set @len=len(@s)
set @i=0
while @i <=@len
begin
if(substring(@s,@i,1)= ', ')
begin
set @sum=@sum+cast(@s1 as int)
set @s1= ' '
end
else
begin
set @s1=@s1+substring(@s,@i,1)
end
set @i=@i+1
end
return(@sum)
--print cast(@sum as int)
end


select dbo.sum_data( '12,32,52,72,19, ')


-----------
187

(1 row(s) affected)