Mongoose unique index on subdocument

Question

Let\'s say I have a simple schema:

var testSchema = new mongoose.Schema({
    map: { type: [ mongoose.Schema.Types.Mixed ], default: [] },
    ...possibly so         


        

Answer 1

This comes up in google so I thought I'd add an alternative to using an index to achieve unique key constraint like functionality in subdocuments, hope that's OK.

I'm not terribly familiar with Mongoose so it's just a mongo console update:

var foo = { _id: 'some value' }; //Your new subdoc here

db.yourCollection.update(
{ '_id': 'your query here', 'myArray._id': { '$ne': foo._id } },
{ '$push': { myArray: { foo } })

With documents looking like:

{
  _id: '...',
  myArray: [{_id:'your schema here'}, {...}, ...]
}

The key being that you ensure update will not return a document to update (i.e. the find part) if your subdocument key already exists.