Question

i’m founding a solution of checking the empty resultset… here is the code

     temp = rs1;
     boolean hasRows = temp.next();


     if (hasRows) {  
        while (rs1.next()) {
            String pid = rs1.getString("pid");
            System.out.println(pid);
            String pd = rs1.getString("description");
            double price = rs1.getDouble("price");%>
                    <br>
                    Product id : <%=pid %><br>
                    Description : <%=pd %><br>
                    Price : <%=price %>
      <%
                }
          }

it seems that temp.next() will affect rs.next(), the result can’t be printed out finally. Why?

Answer 1

next() method already checks the control that you try. If result set rs1 has elements the loop will be entered.
You don’t seem to use temp anywhere. Why? Abandon it and get your job done, try this:

      boolean loopEntered = false;
      while (rs1.next())
      {
                loopEntered = true;
                String pid = rs1.getString("pid");
                System.out.println(pid);
                String pd = rs1.getString("description");
                double price = rs1.getDouble("price");

              %>
                 <br>
                 Product id : <%=pid %><br>
                 Description : <%=pd %><br>
                 Price : <%=price %>
              <%
      }

      if(!loopEntered)
      // print your error messages.