I have a web application where users fill out a form and submit it to my backend server. The frontend uses JavaScript to send the data, and my server runs on Node.js with Express framework connected to a MySQL database. The problem happens when users click the submit button more than once by mistake. This creates several identical requests that all get processed, so I end up with duplicate records in my database table. What are some good ways to prevent this from happening? I want to make sure each form submission only creates one database entry, even if the user clicks submit multiple times quickly.
disabling the submit button after the first click is a smart move! just set disabled=true in your js when it submits, and re-enable it after you get a response. maybe add a loading spinner so users see somethings happening. it’ll stop those repeat clicks!
Had this exact problem in production last year. Here’s what actually worked: server-side duplicate detection with database transactions and unique constraints. Set up a composite unique index on the relevant MySQL fields, then wrap your insert in a try-catch to handle duplicate key errors. Also add request deduplication middleware that tracks recent submissions using Redis with short expiration times. This catches duplicates even when users bypass client-side stuff. Database constraints + server-side request tracking = solid protection no matter what users do or how flaky the network gets.
interesting problem! what about using a unique id or timestamp for each form? you could generate a uuid when the form loads and include it with the submission. what’s your current database schema like? any unique constraints already set up?