如何使用mongodb中的时间戳在特定时间触发函数？

Question

Let's say i am storing some timestamps in my MongoDB, each timestamp indicates a time when some certain function should be run.

I am not sure what should be the correct approach to this since I am new in backend developing.

Mongo data structure goes like this(this is just an example):

{id: 115155, userId: 152115, timestamp: 13-09-2019:15:30:00}

and on this certain time I want to trigger a function:

someFunction(eventId, userId){ ...something here }

Answer 1

You need to change the format of timestamp you get from mongodb into something like this - "13 Sept 2019 18:39:40" or "2019-01-01 00:00:00". Then you need to parse the timestamp you get from mongodb using this Date.parse()

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/parse

Once that is done you need to get difference between timestamp and current time and use that difference in a setTimeout() function, which takes 2 parameters - function to be run and time in milliseconds

    let timediff = new Date() - Date.parse("2019-09-13 18:54:50");

    setTimeout(function() { 
        console.log("Called when current time = mongodb timestamp"); 
    }, timediff);