title: PlSQL showing compilation error
body: <p>PL/SQL is showing compilation error. Function is working correctly and successfully compiled, but if running pl/sql query then showing compilation.</p>
  
  <pre><code>CREATE OR REPLACE FUNCTION f(
     num  IN  NUMBER,
     num2 IN  NUMBER,
     ans  OUT NUMBER 
  ) RETURN number IS 
  BEGIN 
    ans := num + num2;
    RETURN ans;
  END;
  
  CREATE table add1(val1  number(2),val2  number(1),ans  number(3));
  
  SET SERVEROUTPUT ON ;
  
  DECLARE 
    a1  add1.val1%TYPE;
    b1  add1.val2%TYPE;
    sum add1.ans%TYPE;
  BEGIN
    WHILE a1!=-99
    LOOP
      a1 := &amp;a1;
      b1 := &amp;b1;
      sum := f(a1, b1, sum);
      INSERT INTO add1 VALUES(a1, b1, c1);
    END LOOP;
  END;
  </code></pre>