Mongo & Mongoose

What is an ODM?

"Object Document Mapper"

Mongoose setup

$ npm install --save mongoose

Mongoose setup

var mongouri = 'mongodb://username:password@host:51625/db-name';

mongoose.connect(mongouri);

//handle connection error
mongoose.connection.on('error', function(e){
  console.error(e);
});

var mongouri = process.env.MONGOURI; //set in process.env

Schema & Models

//schema//
var dishSchema = mongoose.Schema({
  name: String,
  spicy: Boolean
});

var restaurantSchema = mongoose.Schema({
  name: String,
  founded: Number,
  Dishes: [ dishSchema ]
});

//model//
var Restaurant = mongoose.model('Restaurant', restaurantSchema);

Relationships Population

• Restaurants Collection and Dishes collection
• Enter foreign key IDs like SQL
• Mongoose "populates" the Restaurant with related Dishes

Relationships Sub-documents

var restaurantSchema = mongoose.Schema({ /* name, founded, ...*/
  Dishes: [ dishSchema ]
});

[
  {
   "_id": { "$oid": "56afe2b362e2946e89dd0e38" },
  "name" : "Amici's",
  "founded": 2010,
  "Dishes": [
    {
      "name" : "tacos",
      "spicy" : true 0},
      "_id": { "$oid": "56afe2b362e2946e89dd0e3f" },
    ...
  },
  ...
]

Syncing Models

Nope!

In mongoose-restaurants...

1. npm install
2. edit index.js to match your environment
3. node .
4. Explore data: https://mongolab.com
/databases/{db}/collections/restaurants

Hints:

• Feel free to hardcode the mongoURI
  • Otherwise, export MONGOURI=<yourmongouri>
• get mongoURI from https://mongolab.com/databases/{db}

restaurants collection

[
  {
      "_id": {
          "$oid": "56afe2b362e2946e89dd0e25"
      },
      "name": "Taco Gong",
      "founded": 2011,
      "Dishes": [
          {
              "name": "Pancakes",
              "spicy": false,
              "_id": {
                  "$oid": "56afe2b362e2946e89dd0e2c"
              }
          },
          ...

Queries

• Model.findOne
• Model.findById
• Model.find
• Take callbacks

Model.find([conditions, projection, options,] callback);

Post.find(handlePosts);

function handlePosts(err, posts){
  //do something with posts Array
}

Promises

Post.find()
  .exec()
  .then(handlePosts)
  .catch(function(e){ console.error(e); });

function handlePosts(posts){
  //do something with posts Array
}

Connect the /restaurants/ route

Hints:

• Promise!! (and exec)

  Model.find().exec()
    .then(function(results){
      //use results
    });
  

• Template expects an object with a restaurants key:

  each restaurant in restaurants
    li
      a(href='/restaurants/' + restaurant.id)= restaurant.name
  

Query Conditions

Post.find({ featured : true })
  .exec().then(handler);

Post.find()
  .where({featured : true })
  .exec().then(handler);

Query Conditions

Person
  .find({ occupation: /host/ })
  .where('name.last').equals('Ghost')
  .where('age').gt(17).lt(66)
  .where('likes').in(['walking', 'talking'])
  .limit(10)
  .sort('-occupation')
  .exec().then(handler);

Attributes Projections

var query = Post.find(
    {featured : true},
    'title slug description' //fields to "project"
  )
  .exec().then(handler);

Post.find()
  .where({featured : true })
  .select('title slug description')
  .exec().then(handler);

Relations Sub-documents

Included by default

[
  {
   "_id": { "$oid": "56afe2b362e2946e89dd0e38" },
  "name" : "Amici's",
  "founded": 2010,
  "Dishes": [
    {
      "name" : "tacos",
      "spicy" : true 0},
      "_id": { "$oid": "56afe2b362e2946e89dd0e3f" },
    ...
  },
  ...
]

Connect the /restaurants/:id route

Hints:

• id passed in req.params
• findById
• Promise!! (and exec!!)
• Template expects an object with name, founded, Dishes keys

Saving data

Build & Save

var hd_post = new Post({
  title : 'Are Hotdogs Sandwiches?'
});

hd_post.contents = postContents;
hd_post.save();

Create

Post.create({
  title : 'Are Hotdogs Sandwiches?',
  contents : postContents
})
.then(function(hd_post){ ... });

Updating data

Post
  .findById(123)
  .then(function(hd_post){
    hd_post.title = 'The Hotdog Dilemma'
    hd_post.save;
  }).exec(callback);

var oldTitle = 'Are Hotdogs Sandwiches?';
var newTitle = 'The Hotdog Dilemma';

Post.findOneIdAndUpate(
  { title : oldTitle},
  { title : newTitle}
).exec(callback);

Connect the POST /restaurants/ route

Hints:

• req.body (already parsed! ☺)
• no need for exec
• create or new Model & save
• You may experience code déjà vu...

THANKS FOR COMING!!!

http://bit.ly/fluent-node-feedback