PL/SQL TD5 EX1

DECLARE
  CURSOR quant IS
  (
    SELECT QUANTITE
    FROM Commande
    WHERE QUANTITE IS NOT NULL;
  )
  quant_temp NUMBER:=0;
  quant_eval NUMBER:=0;
  quantite NUMBER;
  cpt NUMBER:=0;
BEGIN
  OPEN quant;
  FETCH quant INTO quant_temp;
  LOOP
    FETCH quant INTO quantite
    EXIT WHEN quant%NOTFOUND;
    quant_val := quant_val + QUANTITE - quant_temp;
    quant_temp := QUANTITE;
    cpt := cpt + 1;
  END LOOP;
  DBMS_OUTPUT.put_line("Totale: "||quant_val/cpt);
EXCEPTION
  WHEN DATA_NO_FOUND THEN
    DBMS_OUTPUT.put_line("Commande is empty!");
END;
/