# Mongo - Mongoose

## Lesson Objectives
1. Explain ODM
1. Explain Schema
1. Explain Create/Save
1. Explain Find
1. Explain Update
1. Explain Remove
1. Explain Helper Functions

## Explain ODM

## Explain Schema

article.js

```javascript
var mongoose = require('mongoose');
mongoose.set('debug', true);
var Schema = mongoose.Schema;

var articleSchema = new Schema({
	title:  { type: String, required: true, unique: true },
	author: { type: String, required: true },
	body:   String,
	comments: [{ body: String, date: Date }],
	date: { type: Date, default: Date.now },
	hidden: Boolean,
	meta: {
		votes: Number,
		favs:  Number
	}
});

//Creating an Article class -- will be stored in 'articles' collection
var Article = mongoose.model('Article', articleSchema);

module.exports = Article;
```
1. String
1. Number
1. Date
1. Boolean
1. Mixed
1. ObjectId
1. Array

## Explain Create/Save
```javascript
var mongoose = require('mongoose');
var db = mongoose.connection;
var Article = require('./article.js');

//Setting up a new article
var newArticle = new Article({
    title: 'Awesome Title',
    author: 'Matt'
});

newArticle.hidden = false;

//connect to mongo
mongoose.connect('mongodb://localhost:27017/example');

//if the connection fails
db.on('error', function(){
  console.log('error');
});

db.once('open', function() {
  //we're connected!
  //save article to the database
  newArticle.save(function(err, article) {
      if(err) {
          console.log(err);
      } else {
          console.log(article);
      }
      mongoose.connection.close();
  });
});
```

## Explain Find
```javascript
Article.find({author:'Matt'}, 'name -_id',function(err, articles){
	console.log(articles);
	mongoose.connection.close();
})
```

## Explain Update
```javascript
Article.update({ author: 'Matt' }, { $set : { author: 'Matthew' } }, { multi: true }, function (err, response) {...});
```

## Explain Remove
```javascript
Article.remove({author:'Matt'}, function(err){...});
```
```javascript
Article.findOne({title:'Harry Potter'}, function(err, article){
  article.remove();
});
```

## Explain Helper Functions
1. findById
1. findOne
1. findByIdAndUpdate
1. findByIdAndRemove
1. findOneAndUpdate
1. findOneAndRemove