一定时间后，node.js发出事件

Question

I have a database that has data inserted to it with a timestamp. Once this timestamp is more than 24 hours before the current time I want an event to be emitted that causes the data to be deleted since it has been expired.

How can this be done? I am running a http server so I can't afford constant checks since it would slow down each request and if a large amount of information accumulates it would take a long time to check each and every one. I also want to avoid having to spawn a child process if at all possible.

Any ideas?

Answer 1

You can use node-schedule to schedule jobs (arbitrary functions) for execution at specific dates.

For example, the following would run a function 24 hours from the time it was invoked:

var schedule = require('node-schedule');
var futureDate = new Date(new Date().getTime() + 60 * 60 * 24 * 1000); // This is 24 hours from *now*

var j = schedule.scheduleJob(futureDate, function(){
  console.log('Do your work here.');
});

Answer 2

您想从数据库中删除数据，为什么不使用crontab？