mongoose push to attribute code example

Example 1: how to append data to a field in mongoose model

//mongoose appending data

var objFriends = { fname:"fname",lname:"lname",surname:"surname" };
Friend.findOneAndUpdate(
   { _id: req.body.id }, 
   { $push: { friends: objFriends  } },
  function (error, success) {
        if (error) {
            console.log(error);
        } else {
            console.log(success);
        }
    });
)

Example 2: add in to array mongoose

// With { $push: { field: element } }

// Example:
const elementToPush = { a: 1, b: 2 };
const body = { $push: { arrayField: elementToPush } };
model.patch(id, body);