Delete row from database automatically after 24 hours [closed]

Answer 1

To your question, there are many ways to do it:

1. Cron job (external to your app)
2. In-app (server side) job (new EvTimer() in php, setInterval() in node/js, javax.swing.Timer in Java, ETC.)
3. Thread + sleep (please don't do that)
4. Alarm signal (you should probably not)

But instead of deleting on an interval and relying on it, I suggest the below, it will also give you correctness of exact 24h (you might not require it, but it is good anyway):

• your records need to be timestamped (almost every solution will require this)
• when you read the records, filter out records that the timestamp is less than now minus 24 hours
• delete the old records (cleanup) on an interval, say once a day, using cron job oe in-app job.

Answer 2

While it would certainly be a bad idea to add a cron job for every row of your database, I don't see a problem of running a cron job running (e.g.) every hour (or every 30mins, or once a day), which deletes every entry older than 24 hours.

You can furthermore make sure that no entries older than 24 hours are ever returned when querying them.

Answer 3

What you're looking at is something effectively like this:

DELETE FROM snaps WHERE created_at<=DATE_SUB(NOW(), INTERVAL 1 DAY)

So long as you populate created_at and index it, this should run fairly quickly. If you have lots of records, and by that I mean over 100 million, you'll need to space that out:

DELETE FROM snaps ... LIMIT 10000

Where you can do it in chunks of 10K or whatever works best.