只取字母的函數

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