When refreshing browser

Question

HI....
I am facing the problem when refreshing the browser.
Eg:
if we have one webpage which have feilds like name and dataofbirth.if we enter the data and submit it the data will be insert into the database.if i refresh the browser then again the same data is inserting into database.how many times i am refreshing the webpage those many times the operation is performing and so many rows are inserting into database with same data.How to restrict this... how to restrict updation of database with previous feilds data when page get refreshed...pls help in this..its little bit urgent

Answer 1

I utilize 3 techniques to prevent double posts:
1. I disable the submit button prior to submitting the page (via javascript). If you do this, note that the button name is NOT submitted with the page parameters.
2. Redirection after the POST to the target page.
3. Add a unique request ID to each POST page. Store submitted unique ID's in an application level collection, and then if that ID is seen again, throw a "page already submitted exception".
Option 1 works well on the client side. But it doesn't prevent the user from right clicking and hitting "refresh" on the result page. Option 2 prevents the right click, refresh. However, at any time, a user can hit Back-Back-Back to get to your form again, at which time they may try to re-submit. For those cases, I also add option #3.
For option 3, I typically put a field such as:
<input type="hidden" name="uniquerequestid" value="<%=strUniqueValue%>">
Every time a request comes through my main handler, I look for the "uniquerequestid" parameter, and if found I check to see if the value has already been submitted. If it hasn't, I add the value to the list of values. If it has, I throw an exception and take the user to a page that says "This page has already been submitted".
Note that the unique request cache list must be stored in the application level, NOT the user session level, else users could hit back as many times as necessary, even when logged in via another user. So I don't store this data in the session.
I then clear my cache list ever few hours, leaving in the most recent ones, and getting rid of old ones.
Hope that helps!
Michael