Push items into mongo array via mongoose

Question

I\'ve scoured SO a good bit looking for the answer but I\'m sure that I\'m lost for the right words to describe what I\'m after.

Basically I have a mongodb collection

Answer 1

Another way to push items into array using Mongoose is- $addToSet, if you want only unique items to be pushed into array. $push operator simply adds the object to array whether or not the object is already present, while $addToSet does that only if the object is not present in the array so as not to incorporate duplicacy.

PersonModel.update(
  { _id: person._id }, 
  { $addToSet: { friends: friend } }
);

This will look for the object you are adding to array. If found, does nothing. If not, adds it to the array.

References: https://docs.mongodb.com/manual/reference/operator/update/addToSet/ https://mongoosejs.com/docs/api/array.html#mongoosearray_MongooseArray-addToSet

Answer 2

Use $push to update document and insert new value inside an array.

find:

db.getCollection('noti').find({})

result for find:

{
    "_id" : ObjectId("5bc061f05a4c0511a9252e88"),
    "count" : 1.0,
    "color" : "green",
    "icon" : "circle",
    "graph" : [ 
        {
            "date" : ISODate("2018-10-24T08:55:13.331Z"),
            "count" : 2.0
        }
    ],
    "name" : "online visitor",
    "read" : false,
    "date" : ISODate("2018-10-12T08:57:20.853Z"),
    "__v" : 0.0
}

update:

db.getCollection('noti').findOneAndUpdate(
   { _id: ObjectId("5bc061f05a4c0511a9252e88") }, 
   { $push: { 
             graph: {
               "date" : ISODate("2018-10-24T08:55:13.331Z"),
               "count" : 3.0
               }  
           } 
   })

result for update:

{
    "_id" : ObjectId("5bc061f05a4c0511a9252e88"),
    "count" : 1.0,
    "color" : "green",
    "icon" : "circle",
    "graph" : [ 
        {
            "date" : ISODate("2018-10-24T08:55:13.331Z"),
            "count" : 2.0
        }, 
        {
            "date" : ISODate("2018-10-24T08:55:13.331Z"),
            "count" : 3.0
        }
    ],
    "name" : "online visitor",
    "read" : false,
    "date" : ISODate("2018-10-12T08:57:20.853Z"),
    "__v" : 0.0
}