带Javascript的所有MongoDB文档中的Update字段

Question

I'm trying to update a field for every Document in a MongoDB collection.

I added the field from the Mongo shell, but I want to change each fields' value to a random number.

User.find({}, function(err, items){
  if (err){
    consele.log('err');
    consele.log(err);
  }
  items.forEach(function(item){
    var time = (Math.floor(Math.random() * (1474893715201 - 1474800000000) + 1474800000000));
    item.update({}, {$set:{"lastLogin": time}}, false, true);
  });
});

If I console.log(item) in the .forEach loop, I get each document in the collection as I'd expect, so everything up to there seems to be working.

Can anyone see where I'm going wrong?

Thanks peoples!

Answer 1

The Api calls are asynchronous, your going to have to wrap this in a promise, or async library to get the build changes done.

Alternatively you can also do a bulk find and update through mongo in one call: https://docs.mongodb.com/manual/reference/method/Bulk.find.update/

var bulk = db.items.initializeUnorderedBulkOp();
bulk.find( { status: "D" } ).update( { $set: { status: "I", points: "0" } } );
bulk.find( { item: null } ).update( { $set: { item: "TBD" } } );
bulk.execute();

Answer 2

why not something like

User.find({}, function(err, items){
  if (err){
    consele.log('err');
    consele.log(err);
  }
  items.forEach(function(item){
    var time = (Math.floor(Math.random() * (1474893715201 - 1474800000000) + 1474800000000));
    item.lastLogin = time;
    User.save(item); // or item.save() based on driver you are using 
  });
});