Looking for Mongoose "hello world" example

Question

Update: Been some time. But back then decided not to use Mongoose. Main reason being that we couldn't really come up with a great reason for using an ORM when using mongo and javascript.

---

I've been trying to create a database/model with Mongoose which is basically just a user database where the username is unique. Sounds simple enough, but for some reason I've been unable to do so.

What I've got so far is this:

var mongoose = require('mongoose').Mongoose,
    db = mongoose.connect('mongodb://localhost/db');

mongoose.model('User', {
    properties: [
        'name',
        'age'
    ],

    cast: {
        name: String,
        age: Number
    },

    //indexes: [[{name:1}, {unique:true}]],
    indexes: [
        'name'
    ]
    /*,
    setters: {},
    getters: {},
    methods: {}
    */
});    

var User = db.model('User');

var u = new User();
u.name = 'Foo';

u.save(function() {
    User.find().all(function(arr) {
        console.log(arr);
        console.log('length='+arr.length);
    });
});
/*User.remove({}, function() {});*/

It just doesn't work. The database is created alright, but the username is not unique. Any help or knowledge of what I'm doing wrong?

Answer 1

I am aware this question is 10 years old and the original poster abandoned Mongoose, but since it pops up near the top of Google searches I felt I would provide a fresh answer.

Providing a complete basic example, using Typescript. I have added comments in the code, where appropriate.

async function mongooseHelloWorld () {
    const url = 'mongodb://localhost/helloworld';

    // provide options to avoid a number of deprecation warnings
    // details at: https://mongoosejs.com/docs/connections.html
    const options = {
        'useNewUrlParser': true,
        'useCreateIndex': true,
        'useFindAndModify': false,
        'useUnifiedTopology': true
    };

    // connect to the database
    console.log(`Connecting to the database at ${url}`);
    await mongoose.connect(url, options);

    // create a schema, specifying the fields and also
    // indicating createdAt/updatedAt fields should be managed
    const userSchema = new mongoose.Schema({
        name:{
            type: String,
            required:true
        },
        email: {
            type: String,
            required: true
        }
    }, {
        timestamps: true
    });

    // this will use the main connection. If you need to use custom
    // connections see: https://mongoosejs.com/docs/models.html
    const User = mongoose.model('User', userSchema);

    // create two users (will not be unique on multiple runs)
    console.log('Creating some users');
    await User.create({ name: 'Jane Doe', email: '[email protected]' });
    await User.create({ name: 'Joe Bloggs', email: '[email protected]' });

    // Find all users in the database, without any query conditions
    const entries = await User.find();
    for (let i = 0; i < entries.length; i++) {
        const entry = entries[i] as any;
        console.log(`user: { name: ${entry.name}, email: ${entry.email} }`);
    }
}

// running the code, and making sure we output any fatal errors
mongooseHelloWorld()
    .then(() => process.exit(0))
    .catch(error => {
        console.log(error)
    });

Note, this was validated with Mongoose 5.9.26, running against Mongo 4.0.13.

Answer 2

You need to define the schema. Try this: (

var mongoose = require('mongoose').Mongoose,
db = mongoose.connect('mongodb://localhost/db'),
Schema = mongoose.Schema;

mongoose.model('User', new Schema({
    properties: [
        'name',
        'age'
    ],

    [...]
}));    

Answer 3

For Mongoose 2.7 (tested in Node v. 0.8):

var mongoose = require('mongoose'),
    Schema = mongoose.Schema;

var db = mongoose.connect('mongodb://localhost/db');

var User = new Schema({
  first_name: String,
  last_name: String
});

var UserModel = mongoose.model('User', User);

var record = new UserModel();

record.first_name = 'hello';
record.last_name = 'world';

record.save(function (err) {

  UserModel.find({}, function(err, users) {

    for (var i=0, counter=users.length; i < counter; i++) {

      var user = users[i];

      console.log( "User => _id: " + user._id + ", first_name: " + user.first_name + ", last_name: " + user.last_name );

    }

  });

});