create procedure que retorne solo numeros

[Carmelo Cash]

Código SQL [-]
SET TERM ^;
Create Procedure SoloNumeros (num varchar(30)) returns (Numero varchar(30)) as
declare i integer;
declare res varchar(30);
begin
  res='';
  i=1;
  while (i<=char_length(:num)) do begin
    if ((substring(:num from i for 1) > ascii_char(29) ) and (substring(:num from i for 1)< ascii_char(40))) then begin
      res =res||substring(:num from i for 1);
    end 
    i=i+1;
  end
  result=res;
  suspend;
end ^
SET TERM ;^