我有一个名为 updategroup.jsp 的网页，在此我有一个名为 groupname 的组合框，我将所有可用的组名从数据库中获取到此下拉框，基于下拉框中选择的值，我必须从数据库中获取数据和我应该显示在文本框中，我需要更新 mysql 表。但我的问题是，如果我选择第一个组合框值，每当我在组合框中选择第二个值时，我都会获得值，在 textbaoxes 中显示以前的值并且总 mysql 表是更新。以下是 updategroup.jsp 的代码：
<%@page import="java.sql.*"%>
<%@page import="javax.servlet.*"%>
<%
Connection con=null;
String sqlQuery="";
Statement st=null;
ResultSet rs=null;
String groupname_var="";
String data_firstname="";
String data_lastname="";
String data_middlename="";
String data_add1="";
String data_add2="";
String data_city="";
String data_state="";
String data_country="";
int data_zip=0;
String data_phone="";
String data_mn="";
String data_emailid="";
%>
<html>
<head>
<title>edit user</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<link rel="stylesheet" href="styles.css" type="text/css" media="screen" />
<link rel="stylesheet" href="style.css" type="text/css" media="screen" />
<style>
td{FONT: 13px Arial,sans-serif;}
th{FONT:bold 13px Arial, sans-serif;color:white;background-color:#153e7e}
input{FONT: 13px Arial,sans-serif;border: solid 1;}
select{font: 13px Arial,sans-serif}
#button{cursor:hand}
A:hover {COLOR: red}
textarea {
resize: none;
}
td{
border:none;
}
</style>
<script type="text/javascript">
function reset()
{
alert("etst");
document.getElementByID("subzone").value="";
}
</script>
<script type="text/javascript">
window.history.forward();
function noback() { window.history.forward(); }
</script>
<script type="text/javascript">
function myoriginaldata()
{
document.getElementById("fn").value=document.getElementById("hfn").value;
document.getElementById("ln").value=document.getElementById("hln").value;
document.getElementById("mn").value=document.getElementById("hmn").value;
document.getElementById("add1_id").value=document.getElementById("hadd1").value;
document.getElementById("add2_id").value=document.getElementById("hadd2").value;
document.getElementById("city_id").value=document.getElementById("hcity").value;
document.getElementById("state_id").value=document.getElementById("hstate").value;
document.getElementById("country_id").value=document.getElementById("hcountry").value;
document.getElementById("zip_id").value=document.getElementById("hpostalcode").value;
document.getElementById("phone_id").value=document.getElementById("hphoneno").value;
document.getElementById("mobile_id").value=document.getElementById("hmobileno").value;
document.getElementById("email_id").value=document.getElementById("hemailid").value;
}
</script>
</head>
<form method="post" name="frm_addUser" action="./updategroup.jsp">
<table width="40%;" border="0" cellpadding="5" cellspacing="1" bgcolor="" bordercolor="#333366" align="center">
<tbody>
<tr><th colspan="2" align="middle"><font size="4">Edit Group</font></th></tr>
<tr>
<td bordercolor="Gainsboro"><font size="4">Group Name</font></td>
<%
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection("jdbc:mysql://localhost:3306/suwatermeter","root","sumith");
sqlQuery="select groupname from grouplist";
st=con.createStatement();
rs=st.executeQuery(sqlQuery);
%>
<td><select name="group_name" id="gid" style="WIDTH: 200px" onchange="this.form.submit()">
<option value="">Select groupname</option>
<% while(rs.next()) {%>
<option value="<%=rs.getString("groupname")%>"><%=rs.getString("groupname")%></option>
<% }
rs.close();
st.close();
con.close();
%>
</td>
</tr>
<%
groupname_var=request.getParameter("group_name");
Class.forName("com.mysql.jdbc.Driver");
con=DriverManager.getConnection("jdbc:mysql://localhost:3306/suwatermeter","root","sumith");
sqlQuery="select firstname,middlename,lastname,address1,address2,city,state,country,zipcode,phoneno,mobileno,emailid from groupdata where group_name='"+groupname_var+"'";
st=con.createStatement();
rs=st.executeQuery(sqlQuery);
while(rs.next())
{
data_firstname=rs.getString("firstname");
data_lastname=rs.getString("lastname");
data_middlename=rs.getString("middlename");
data_add1=rs.getString("address1");
data_add2=rs.getString("address2");
data_city=rs.getString("city");
data_state=rs.getString("state");
data_country=rs.getString("country");
data_zip=rs.getInt("zipcode");
data_phone=rs.getString("phoneno");
data_mn=rs.getString("mobileno");
data_emailid=rs.getString("emailid");
}
rs.close();
st.close();
con.close();
%>
<input type="hidden" id="hgroupname_id" value="<%=groupname_var%>">
<tr>
<td bordercolor="Gainsboro"><font size="4">First Name </font></td>
<td bordercolor="Gainsboro"><input name="firstname" style="WIDTH: 200px" value="<%=data_firstname%>" id="fn"></td></tr>
<tr>
<td bordercolor="Gainsboro"><font size="4">Middle Name </font></td>
<td bordercolor="Gainsboro"><input name="middlename" style="WIDTH: 200px" value="<%=data_middlename%>" id="mn"></td></tr>
<tr>
<td colspan="1" bordercolor="Gainsboro"><font size="4">Last Name </font>
<td bordercolor="Gainsboro"><input name="lastname" style="WIDTH: 200px" type="text" value="<%=data_lastname%>" id="ln">
</td>
</tr>
<tr>
<td colspan="1" bordercolor="Gainsboro"><font size="4" color="green"><i>Address</i></font>
</td>
<td bordercolor="Gainsboro">
</td></tr>
<tr>
<td bordercolor="Gainsboro"><font size="4">Line 1</font></td>
<td bordercolor="Gainsboro"><input name="lineone" style="WIDTH: 200px" value="<%=data_add1%>" id="add1_id"></td></tr>
<tr>
<td bordercolor="Gainsboro"><font size="4">Line 2</font></td>
<td bordercolor="Gainsboro"><input name="linetwo" style="WIDTH: 200px" value="<%=data_add2%>" id="add2_id"></td></tr>
<tr>
<td bordercolor="Gainsboro"><font size="4">City</font></td>
<td bordercolor="Gainsboro"><input name="city" style="WIDTH: 200px" value="<%=data_city%>" id="city_id"></td></tr>
<tr>
<td bordercolor="Gainsboro"><font size="4">State</font></td>
<td bordercolor="Gainsboro"><input name="state" style="WIDTH: 200px" value="<%=data_state%>" id="state_id"></td></tr>
<tr>
<td bordercolor="Gainsboro"><font size="4">Country</font></td>
<td bordercolor="Gainsboro"><input name="country" style="WIDTH: 200px" value="<%=data_country%>" id="country_id"></td></tr>
<tr>
<td bordercolor="Gainsboro"><font size="4">Pin/Zip Code </font></td>
<%
if(data_zip!=0)
{ %>
<td bordercolor="Gainsboro"><input name="postalcode" style="WIDTH: 200px" value="<%=data_zip%>" id="zip_id"></td></tr>
<%
}
%>
<tr>
<td bordercolor="Gainsboro"><font size="4">Phone No</font></td>
<td bordercolor="Gainsboro"><input name="phoneno" value="<%=data_phone%>" style="WIDTH: 200px" id="phone_id"></td></tr>
<tr>
<td bordercolor="Gainsboro"><font size="4">Mobile No</font></td>
<td bordercolor="Gainsboro"><input name="mobileno" style="WIDTH: 200px" value="<%=data_mn%>" id="mobile_id"></td></tr>
<tr>
<td bordercolor="Gainsboro"><font size="4">E-Mail </font></td>
<td bordercolor="Gainsboro"><input name="email" style="WIDTH: 200px" value="<%=data_emailid%>" id="email_id"></td></tr>
<tr>
<td align="center" colspan="2" bordercolor="#f8f8ff">
<input type="submit" value="Update" style="BORDER-RIGHT: green 1px solid; BORDER-TOP:GREEN 1px solid; FONT: GREEN 8pt Tahoma; BORDER-LEFT: GREEN 1px solid; WIDTH: 90px; BORDER-BOTTOM: GREEN 1px solid; HEIGHT: 34px" name="bOk" onclick="return checkInput();">
<input type="reset" value="Cancel" style="BORDER-RIGHT: GREEN 1px solid; BORDER-TOP:GREEN 1px solid; FONT: GREEN 8pt Tahoma; BORDER-LEFT: GREEN 1px solid; WIDTH:90px; BORDER-BOTTOM: GREEN 1px solid; HEIGHT: 34px" name="cancel">
</td></tr>
<%
try
{
String fn_var=request.getParameter("firstname");
String ln_var=request.getParameter("lastname");
String mn_var=request.getParameter("middlename");
String add1_var=request.getParameter("lineone");
String add2_var=request.getParameter("linetwo");
String city_var=request.getParameter("city");
String state_var=request.getParameter("state");
String country_var=request.getParameter("country");
String zipcode_var=request.getParameter("postalcode");
String phone_var=request.getParameter("phoneno");
String mobile_var=request.getParameter("mobileno");
String email_var=request.getParameter("email");
Class.forName("com.mysql.jdbc.Driver");
con=DriverManager.getConnection("jdbc:mysql://localhost:3306/suwatermeter","root","sumith");
st=con.createStatement();
%>
<input type="hidden" id="hfn" value="<%=fn_var%>">
<input type="hidden" id="hmn" value="<%=mn_var%>">
<input type="hidden" id="hln" value="<%=ln_var%>">
<input type="hidden" id="hadd1" value="<%=add1_var%>">
<input type="hidden" id="hadd2" value="<%=add2_var%>">
<input type="hidden" id="hcity" value="<%=city_var%>">
<input type="hidden" id="hstate" value="<%=state_var%>">
<input type="hidden" id="hcountry" value="<%=country_var%>">
<input type="hidden" id="hpostalcode" value="<%=zipcode_var%>">
<input type="hidden" id="hphoneno" value="<%=phone_var%>">
<input type="hidden" id="hmobileno" value="<%=mobile_var%>">
<input type="hidden" id="hemailid" value="<%=email_var%>">
<%
if(groupname_var!=null && fn_var!=null && mn_var!=null && ln_var!=null && add1_var!=null && add2_var!=null && city_var!=null && state_var!=null && country_var!=null && zipcode_var!=null && phone_var!=null && mobile_var!=null && email_var!=null)
{
if(!groupname_var.equals("") && !fn_var.equals("") && !ln_var.equals("") && !mn_var.equals("") && !add1_var.equals("") && !add2_var.equals("") && !city_var.equals("") && !state_var.equals("") && !country_var.equals("") && !zipcode_var.equals("") && !phone_var.equals("") && !mobile_var.equals("") && !email_var.equals(""))
{
%>
<script>
myoriginaldata();
</script>
<%
st.executeUpdate("update groupdata set firstname='"+fn_var+"',lastname='"+ln_var+"',middlename='"+mn_var+"',address1='"+add1_var+"',address2='"+add2_var+"',city='"+city_var+"',state='"+state_var+"',country='"+country_var+"',zipcode='"+zipcode_var+"',phoneno='"+phone_var+"',mobileno='"+mobile_var+"',emailid='"+email_var+"' where group_name='"+groupname_var+"'");
}
}
st.close();
con.close();
}
catch(Exception e)
{
}
%>
<script>
document.getElementById("gid").value=document.getElementById("hgroupname_id").value;
</script>
</tbody>
</table>
</form>
</div>
</body>
</html>
please help me to solve this.