duplicate data insert in CodeIgniter

Question

I am just inserting data in codeigniter controller part at pastebin http://pastebin.com/KBtqrAkZ

  public function add_product()
  {
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Answer 1

This is the Double Submit Problem.

There are several ways of dealing with it:

1. The Post / Redirect / Get pattern: Breaks the back button, and it does not keep your user from going back far enough to submit again. Does not handle multiple clicks.

2. Disable the submit button: Handles multiple clicks some of the time, but does not fix the user going back and submitting again.

3. Store a token in the session: If you have multiple tabs open in the browser, the token stored in the session may get mixed up. (Note: It may be possible to create browser tab specific cookies using javascript, but I have not tried it myself.)

4. Change the database to not allow duplicates: The best solution, but also the most effort. If it detects a set of duplicate data, ignore the second request.

5. Unique transaction id: Described on this PHP hacks page, and on this answer.

6. Multiple tokens in the session: A variation on option 3. If you store all generated tokens in the session, you don't need to involve the database. The probability of a duplicate is much lower, given that tokens are unique inside a session. Possible problems include the set of tokens growing out of control. Maybe fixable with a limited size stack where you add to the top of the stack, and extra tokens fall off the bottom. Untested.

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I like the unique transaction id method. It works like this:

1. Generate a random transaction_id and put it in your web form. It goes along when the user clicks submit.

2. When you receive the request to add a product, check for the transaction_id in the transaction table.

3. If the id does not exist in the table, do the transaction, and insert the transaction_id into the table.

4. If the id does exist in the table, the transaction is already done.

You should also search for [double-submit-prevention] in to see if you can find an even better solution.

Answer 2

Theres a simple solution, you can redirect to some other page after adding product, like:

redirect(base_url(). "yourcontrollername/index");

Doing this will remove the post data and data would not be re-added to database.