如何在服务器端检查修改后的表单字段

Question

I am having a form with 700 fields. Suppose if an user updates one or two fields, i want to update that particular fields in Database. My question is how to find that particular(modified) fields in server side, i dont want to execute update query to all the tables. I am using Jboss server, Java, Jsp & MySql

Answer 1

Try this basic approach:

First don't give name attribute to the fields initially. Now when user edits the fields, using javascript give the name attribute to the field. That is it ! On the server side you will always receive data in name=value pair, if there is no name the browser won't pass the field value to the server.

EDIT:

Keep hidden fields with the old values but with no names. This will help you to test whether user has entered new value or not.

This is an example:

script

$(function(){
    $(document).on('input', '.to-edit', function(e) {
        var box = $(this);
        var prv = box.prev().val();
        var cur = box.val();
        if ('' === cur || prv === cur) {
            box.prop('name', '');
        } else {
            box.prop('name', 'txtName');
        }
        e.stopPropagation();
    });
});