mongodb insert.js

insert.js

var mongo = require('mongodb').MongoClient;
var dbName = process.argv[2];
var url = 'mongodb://localhost:27017/'+dbName;
mongo.connect(url, function(err, db){
  if(err) throw err;
  var col = db.collection('users');
  col.update({
    username: 'tinatime'
  },{
    $set: {
      age: 40
    }
  },function(err,data){
    if(err) throw err;
    db.close();
  })
})