只取數字的函數

create function GetNum(@a varchar(50))
returns varchar(50)
as
begin
while patindex('%[^1-9]%',@a)>0
begin
    set @a=stuff(@a,patindex('%[^1-9]%',@a),1,'')
end
return @a
end
go
select dbo.GetNum('2a p9 asdf1234ki  9')
go
drop function GetNum
go
/*                                                  
-------------------------------------------------- 
2912349
*/