Stop data inserting into a database twice

Question

I was wondering what methods/preventions other programmers use to stop data being entered twice into a MySQL database when a user refreshes on the same page as a form? Obvio

Answer 1

You can use a token to prevent the page from being processed again! Such a procedure is used in a lot web frameworks !

The pattern you should use is the "Synchronizer Token Pattern"! If you have a serviceoriented application, you can save your status in the Database.

The data can be send via JavaScript or by a hidden form field.

You should also have a look at libaries with out of the box support for things like this! Grails is such one!

See: http://www.grails.org/1.1-Beta3+Release+Notes ...

...

withForm {
   // good request
}.invalidToken {
   // bad request
}

..