mongoose populate array of object id code example

Example 1: mongodb populate document

Story.
  findOne({ title: 'Casino Royale' }).
  populate('author').
  exec(function (err, story) {
    if (err) return handleError(err);
    console.log('The author is %s', story.author.name);
    // prints "The author is Ian Fleming"
  });

Example 2: mongoos populate a ref

const storySchema = Schema({
  authors: [{ type: Schema.Types.ObjectId, ref: 'Person' }],
  title: String
});

// Later

const story = await Story.findOne({ title: 'Casino Royale' }).populate('authors');
story.authors; // `[]`

Example 3: mongoose populate array of ids

Use the name of the schema path instead of the collection name:

Conversation.findOne({ _id: myConversationId})
.populate('recipients') // <==
.exec(function(err, conversation){
    //do stuff
});