how to submit the option selected from drop down list in jsp page to perform a mysql query

问题

My project is StaffAllocation, and I want to retrieve information from the database. I'm very new and this is my very first project. I created a drop down list retrieving staffnames from one of my table. Now I want to perform a query action to view the details of the selected staffnames from the drop-down list. The following is the coding which i have, which is not correct:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
  pageEncoding="ISO-8859-1"%>
  <%@ page import="java.sql.*" %>
  <%@ page import="java.io.*" %>
  <%@ page import="java.lang.*" %>
  <%@ page import="javax.servlet.*" %>
  <%@ page import="javax.servlet.http.*" %>
  <%ResultSet resultset =null; %>
  <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
  <html>
  <head>
  <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
  <title>Staff Details</title>
  </head>
  <BODY>
  <form method=post>
  <h3>Select Stafftype:</h3>
  <p><input type="radio" name="Stafftype" value="Male"> Male</input></p>
  <p><input type="radio" name="Stafftype" value="Female"> Female</input></p>
  <input type="submit" value="Submit">
  </form>
  <%
  try{

    Class.forName("com.mysql.jdbc.Driver");
    Connection connection =      DriverManager.getConnection("jdbc:mysql://localhost:3306/StaffAllocation?  user=root&password=success");
    Statement statement = connection.createStatement() ;
    String Stafftype= request.getParameter("Stafftype");
    out.print(Stafftype);
    if(Stafftype.contentEquals("Male")){
    resultset=statement.executeQuery("select * from tblstaffdetails where Stafftype=  'Male'");
    }
    else if(Stafftype.contentEquals("Female")){
        resultset=statement.executeQuery("select * from tblstaffdetails where   Stafftype= 'Female'");
    }
    else
    {
        System.out.println("your coding is wrong");
    }
   %>

    <select> <% while(resultset.next()){ %>
    <option><%= resultset.getString(2)%></option>
   <%} %> 

   <%

   String StaffName= request.getParameter("StaffName"); 
   int staffId;
   String subcode;
   if(StaffName != null) {
   resultset=statement.executeQuery("SELECT a.staffId, a.StaffName, b.subcode FROM tblstaffdetails a LEFT JOIN tblsubhandled b ON a.staffId = b.staffId where StaffName='request.getParameter('StaffName')'");

     }       
     }
    catch(Exception e)
    {
         out.println("wrong entry"+e);
    }
    %>
   <form method = "get">
   <br><br>
   <input name="Submit" type="button" value="Submit">
   </form>
   </body>
   </html>`

Tables:

tblstaffdetails -(1).staffId(2).StaffName(3).Stafftype(male or female)

tblsubhandled - (1).staffId(2).subcode

回答1:

I have fiddled sample implementation for your reference. You can implement like that. All you need to do is include jQuery plugin. Sample code lke this,

 $.ajax({
    url : 'ur_servlet_url' + selValue,
    type : "POST",
    async : false,
    success : function(data) {
        //Sample data
        var data = "<select id='child'>
                    <option value='11'>Value11</option></select>"
        $("#fillValue").html(data);
    }
});

You need to compose your java response like select tag and return it to your ajax response. Finally you can fill the second dropdown like that. Let me know if this helps.

回答2:

<form method="post" action="select.jsp">
    <select name="sell">
       <option value="Alto">Alto</option>
       <option value="Esteem">Esteem</option>
       <option value="Honda City">Honda City</option>
       <option value="Chevrolet">Chevrolet</option>
    </select>
    <br>
    <input type="Submit" value="Submit">
</form>
<%
  String st=request.getSelectedIndex("sell");
  if(st!=null){
    out.println("You have selected: "+st);
  }
%>

来源：https://stackoverflow.com/questions/19762001/how-to-submit-the-option-selected-from-drop-down-list-in-jsp-page-to-perform-a-m

标签

java

html

mysql

jsp

servlets