Database changes in radio button in jsp - mysql

Question

I have written a code where the admin has the access to change the general users from active to inactive and vice-versa. So I want to update the database if the radio button is changed from active to inactive.
Here is the code:
<%
while (rs.next()) {
String firstname = rs.getString("firstname");
String lastname = rs.getString("lastname");
String email = rs.getString("email");
String password = rs.getString("password");
String age = rs.getString("age");
String sex = rs.getString("sex");
String haddress = rs.getString("haddress");
String oaddress = rs.getString("oaddress");
String phonenumber = rs.getString("phonenumber");
String flag = rs.getString("flag");
Statement stmt1 = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_READ_ONLY);
%>
<tr>
<td>
Name: <% out.println(firstname); %> <% out.println(lastname); %>
</td>
<td>
<% if (flag.equals("A")){ %>
Active: <input type="radio" value="A" name="<% out.println(email); %>" onclick="<% stmt1.executeUpdate("update assignment set flag='A' where email='"+email+"'");
System.err.println("A"+email); %>
alert('changed to active');" checked>
Inactive: <input type="radio" value="I" name="<% out.println(email); %>" onclick="<% stmt1.executeUpdate("update assignment set flag='I' where email='"+email+"'");
System.err.println("I"+email); %>
alert('changed to inactive');">
<%
}else if(flag.equals("I")){%>
Active: <input type="radio" value="A" name="<% out.println(email); %>" onclick="<% stmt1.executeUpdate("update assignment set flag='A' where email='"+email+"'");
System.err.println("A"+email); %>
alert('changed to active');">
Inactive: <input type="radio" value="I" name="<% out.println(email); %>" onclick="<% stmt1.executeUpdate("update assignment set flag='I' where email='"+email+"'");
System.err.println("I"+email); %>
alert('changed to inactive');" checked>
But in output, when I change one radio button, all the queries run automatically, updating the database to I for all the data in the DB.

Answer 1

Using onclick, you need to invoke a ajax call and update the response . You should not use like onclick="<%SOME SQL Query%>". That is why it's updating all the rows.
Step 1:
" onclick="updatestatus(this.value, '<% out.println(email); %>')"/>
Step 2 :
Add Jquery lib and add a JS function
function updatestatus(statuschg, email) {
/*ajax call to some update-status.jsp with email and current value needs to be passed */
//ajax code goes here ...
$.ajax({
type: "post",
url: "update-status.jsp", //this is my servlet
data: "email=" +email"&status="+statuschg,
success: function(msg){
alert(msg);
}
});
}
Ref: How to invoke ajax call How to pass parameters in GET requests with jQuery
step 3:
i) In update-status.jsp,Establish db connection
ii) receive parameters of the email address and current status.
iii) Execute the Query
stmt1.executeUpdate("update assignment set flag='+status+' where email='"+email+"'")
iv) out.println("Updated");

Answer 2

You are mixing two different codes. The key is to realize, where and when each code is executed - JSP on the server when the page is requested and rendered (i.e. before the response is send to the browser) and Javascript in the browser, after the browser receives the already generated response.
I.e. in your
onclick="<% stmt1.executeUpdate("update assignment set flag='I' where email='"+email+"'"); System.err.println("I"+email); %> alert('changed to inactive');"
the <% stmt1.executeUpdate("update assignment set flag='I' where email='"+email+"'"); System.err.println("I"+email); %> part is executed on the server when the page is generated, and only the alert('changed to inactive'); waits in browser until the input field is clicked.
What you need is AJAX.
Side note: Do not put Java code into JSP, use MVC pattern, or at least put the code into an "util" class and call the class from JSP.