title: Node.js MongoDB Find with projection to exclude _id still returns it
body: <p>Trying to follow the examples <a href="https://www.w3schools.com/nodejs/nodejs_mongodb_find.asp" rel="noreferrer">here</a> to filter by using a projection to exclude _id. The _id still returns:</p>
  
  <p>Code</p>
  
  <pre><code>var MongoClient = require('mongodb').MongoClient;
  var url = "mongodb://localhost:27017/db1";
  
  MongoClient.connect(url, function (err, db) {
      if (err) throw err;
      var dbase = db.db("db1"); //here    
  
      dbase.collection("customers").find(
          {},
          {
              _id: 0
  
          }
          ).toArray(function(err, result) {
          if (err) throw err;
          console.log(result);
          db.close();
      });
  
  });
  </code></pre>
  
  <p>Result still return as follows:</p>
  
  <blockquote>
    <p>[ { _id: 5a2bb2d6ee48575cb54c4365,
        name: 'John',
        address: 'Highway 71' },   { _id: 5a2bb2d6ee48575cb54c436d,
        name: 'Susan',
        address: 'One way 98' },  ....   { _id: 5a2bb2d6ee48575cb54c4371,
        name: 'Chuck',
        address: 'Main Road 989' },   { _id: 5a2bb2d6ee48575cb54c4372,
        name: 'Viola',
        address: 'Sideway 1633' } ]</p>
  </blockquote>
  
  <p>Theoretically _id should not be part of what is returned. What is wrong here?</p>