非法结果集

Question

我得到了这个错误：java.sql.SQLException: Illegal operation on empty result set.我不明白为什么，我循环搜索最终搜索到的行。

rs1=st1.executeQuery("select product.price,product.id from product,warehouse,shop 
           where product.brand ='" 
           + Brand 
           + "' and product.productType='" 
           + Product 
           + "'and shop.quantity + warehouse.quantity='" 
           + Quantity 
           + "' and product.id=shop.idProduct"); 
       while (rs1.next()) { 
        price = rs.getInt("price"); 
        idProduct = rs.getString("id"); 
        countWareHouse++; 
       } 
       if (countWareHouse > 0) { 
        JOptionPane.showConfirmDialog(Sale, 
          "Do you want to add this " + Product 
            + "int the cart?", "CART", 
          JOptionPane.OK_CANCEL_OPTION); 
        Prices.add(price); 
       } 
       } 

Answer 1

在循环中，您使用的是rs而不是rs1。如果这不是发布编译器错误，我假设rs位于全局名称空间中，但在当前状态为空。