如何使用Mongoose将值推入MongoDB中嵌入式文档中的数组？

Question

It seems this may be an open issue with MongoDB, https://jira.mongodb.org/browse/SERVER-831 , but I'm not sure if there's actually a solution and I'm just thinking about and researching things in the wrong way.

Here is a subset of my schema:

var myModel = new mongoose.Schema({

  arrayA: [{
    subArrayA: [{
        fieldA: String
    }],
    subArrayB: [{
        fieldB: String
    }]
  }],

});

I want to update subArrayA by pushing a value into it. I've tried doing this in various ways with no success. This is the simplest attempt:

myModel.findByIdAndUpdate(req.mymodel.arrayA.id(req.params.id), {
        $push: {
            subArrayA: {
                fieldA: valA
            }
        }
}, function(err) {
     // some stuff
});

This works fine when pushing directly to arrayA. For example, the code below executes the way I'd hope - by pushing a value into arrayA:

myModel.findByIdAndUpdate(req.mymodel.id, {
    $push: {
        arrayA: {
            fieldA: valA
        }
    }
}, function(err) {
     // some stuff
});

Answer 1

It seems you are looking for "dot notation" . This is a way of specifying sub-elements of objects without specifying the whole thing.

But you did specify an actual model you your schema did you not:

var Model = mongoose.model( "Model", myModel );
mongoose.connect('mongodb://localhost/test');

Model.findByIdAndUpdate(req.mymodel.arrayA.id(req.params.id), {
        "$push": {
            "arrayA.subArrayA": {
                "fieldA": valA
            }
        }
}, function(err) {
     // some stuff
});

So now you can notate an update without overriding the whole object at a given level.

Answer 2

I was able to get this working with the MongooseArray method 'push'.

req.mymodel.arrayA.id(req.params.id).subArrayA.push({fieldA:ValA});

req.mymodel.save(function (err) {
    // some stuff
});