Using Mongoose, How can I add more items to an object without replacing existing ones?

 User.findOneAndUpdate(
  { userId: 0 },
  { userObjects: { newItem: value } }
 );

The problem with above code is that it clears whatever was there before and replaces it with newItem when I wanted it just to add another item to userObjects(Like push function for javascript arrays).

Using Mongoose, How can I add more items to an object without replacing existing ones?

 User.findOneAndUpdate(
  { userId: 0 },
  { userObjects: { newItem: value } }
 );

The problem with above code is that it clears whatever was there before and replaces it with newItem when I wanted it just to add another item to userObjects(Like push function for javascript arrays).

• javascript
• node.js
• mongodb
• mongoose

• Is your userObjects an array? Can you share your schema? – Ravi Shankar Bharti Commented Nov 23, 2016 at 14:19
• 1 Have a look at my most recent answer in this question for pointers. – chridam Commented Nov 23, 2016 at 14:53

3 Answers 3

Use dot notation to specify the field to update/add particular fields in an embedded document.

User.findOneAndUpdate(
  { userId: 0 },
  { "userObjects.newerItem": newervalue } }
);

or

User.findOneAndUpdate(
  { userId: 0 },
  { "$set":{"userObjects.newerItem": newervalue } }
);

or Use $mergeObjects aggregation operator to update the existing obj by passing new objects

User.findOneAndUpdate(
  {"userId":0},
  [{"$set":{
    "userObjects":{
      "$mergeObjects":[
        "$userObjects",
        {"newerItem":"newervalue","newestItem":"newestvalue"}
      ]
    }
  }}]
)

According to your question, i am guessing userObjects is an array.

You can try $push to insert items into the array.

 User.findOneAndUpdate(
  { userId: 0 },
  { $push : {"userObjects": { newItem: value } }},
  {safe :true , upsert : true},function(err,model)
  {
      ...
  });

For more info, read MongoDB $push reference.

Hope it helps you. If you had provided the schema, i could have helped better.

Just create new collection called UserObjects and do something like this.

UserObject.Insert({ userId: 0, newItem: value }, function(err,newObject){

});

Whenever you want to get these user objects from a user then you can do it using monogoose's query population to populate parent objects with related data in other collections. If not, then your best bet is to just make the userObjects an array.