Error in updating form values in mongoDB using nodejs

You need to read from your req.body, and use those values to create employee body.

router.put("/:id", (req, res) => {  if (!ObjectId.isValid(req.params.id)) {    return res.status(400).send(`Not a valid id ${req.params.id}`);  }  const { email, name, position, office, salary } = req.body;  var emp = { email, name, position, office, salary };  Employee.findByIdAndUpdate(    req.params.id,    { $set: emp },    { new: true },    (err, doc) => {      if (!err) {        if (doc) {          res.send(doc);        } else {          res.status(400).send("Not found");        }      } else {        console.log(err);        res.status(500).send("Something went wrong");      }    }  );});

Let's say you have this employee document.

{    "_id" : ObjectId("5e01d6d21151ad62600b1ba6"),    "name" : "Employee 1",    "position" : "Web developer",    "office" : "Software",    "salary" : 1111,    "email" : "emp1@microsoft.com",    "__v" : 0}

If we want to update position and salary, we can use this request.body:

{    "name": "Employee 1",    "position": "Senior Web developer",    "office": "Software",    "salary": 2222,    "email": "emp1@microsoft.com"}

When you send a PUT request to your route (.../5e01d6d21151ad62600b1ba6) with this body, the result will be like this:

{    "_id": "5e01d6d21151ad62600b1ba6",    "name": "Employee 1",    "position": "Senior Web developer",    "office": "Software",    "salary": 2222,    "email": "emp1@microsoft.com",    "__v": 0}