New to PL/SQL, Please Give examples

[gandolf989]

You want something like this. Although, you should add some error handling, like what do you return when you do not get any rows, or when you get more than one row. And I do not know your table name or column names. Try readiing PL/SQL Best Practices by Steven Feuerstein.

CREATE FUNCTION get_CardNumber (
   p_appid IN cardtable.appid%TYPE )
   RETURN cardtable.cardnumber%TYPE
AS
   v_return cardtable.cardnumber%TYPE;
BEGIN
   SELECT cardnumber
     INTO v_return
     FROM cardtable
    WHERE appid = p_appid;

   RETURN v_return;
END get_CardNumber;
/