DECLARE
  exsist_type    VARCHAR2(50);
  exsist_name    VARCHAR2(50);
  exsist_company VARCHAR2(100);
BEGIN
  SELECT pro_type,
         pro_name,
         company_name
  INTO   exsist_type,
         exsist_name ,
         exsist_company
  FROM   stock;
  
  IF :PURCHASE_DETAIL.pro_type <> exsist_type
    AND
    :PURCHASE_DETAIL.pro_name <> exsist_name
    AND
    :PURCHASE_DETAIL.company_name <> exsist_company THEN
    */
    IF :PURCHASE.radio_type = 'PURCHASE' THEN
      INSERT INTO stock
                  (
                              pro_type ,
                              pro_name ,
                              company_name ,
                              quantity ,
                              purchase_rate,
                              sale_rate ,
                              rack_num
                  )
                  VALUES
                  (
                              :PURCHASE_DETAIL.pro_type,
                              :PURCHASE_DETAIL.pro_name,
                              :PURCHASE_DETAIL.company_name,
                              :PURCHASE_DETAIL.quantity,
                              :PURCHASE_DETAIL.price,
                              :PURCHASE_DETAIL.sale_price,
                              :PURCHASE_DETAIL.rack_num
                  );
    
    END IF;
  ELSIF :PURCHASE_DETAIL.pro_type = exsist_type
    AND
    :PURCHASE_DETAIL.pro_name = exsist_name
    AND
    :PURCHASE_DETAIL.company_name = exsist_name THEN
    IF :PURCHASE.radio_type = 'PURCHASE' THEN
      UPDATE stock
      SET    stock.quantity = stock.quantity+:PURCHASE_DETAIL.quantity
      WHERE  stock.pro_type = :PURCHASE_DETAIL.pro_type
      AND    stock.pro_name = :PURCHASE_DETAIL.pro_name
      AND    stock.company_name= :PURCHASE_DETAIL.company_name;
    
    ELSIF :PURCHASE.radio_type = 'PRCH_RETURN' THEN
      UPDATE stock
      SET    stock.quantity = stock.quantity-:PURCHASE_DETAIL.quantity
      WHERE  stock.pro_type = :PURCHASE_DETAIL.pro_type
      AND    stock.pro_name = :PURCHASE_DETAIL.pro_name
      AND    stock.company_name = :PURCHASE_DETAIL.company_name;
    
    END IF;
  END IF;
END;