TTL expiration of Mongoose referenced document

问题

I have a requirement for setting a TTL on a collection of Docs in my app but also need those docs to be referenced by another collection and am unsure how this would work?

Does setting a TTL on a document remove that document from all other reference docs when it is expired or would I have to write a backend process myself and not use mongoDb's TTL indexes?

An example schema of the functionality I would want :

var mongoose = require('mongoose')
  , Schema = mongoose.Schema

var personSchema = Schema({
    _id     : Number,
    name    : String,
    age     : Number,
    stories : [{ type: Schema.Types.ObjectId, ref: 'Story' }]
});

var storySchema = Schema({
    _creator : { type: Number, ref: 'Person' },
    createdAt: { type: Date, expires: 60*60*24 },
    title    : String,
    fans     : [{ type: Number, ref: 'Person' }]
});

var Story  = mongoose.model('Story', storySchema);
var Person = mongoose.model('Person', personSchema);

So after a Day the Story doc would expire and i would need the ref to that story to expire from the person

回答1:

The built-in TTL doc expiration has no support for removing references to expired docs.

You'll need to provide that functionality in your own code if you need it.

回答2:

You cannot handle this with TTL indexes. You could use a cron job/scheduled task to remove old documents.

I'd suggest you read this, a nice lightweight way of implementing background processes on MongoDb.

来源：https://stackoverflow.com/questions/22808931/ttl-expiration-of-mongoose-referenced-document