lecture02-outline.md

Mongoose

• Setup
  • Follow all instructions for the Puppy database in lecture 1
  • Be sure to keep the age field when refactoring the code and splitting the functionality into different files.
• Read
  • Find

    Puppy.find({ likes: 'snacks' }).exec().then(function (result) {
      console.log(result);
      mongodb.disconnect();
    }).catch(function (err) {
      console.log(err);
      mongodb.disconnect();
    });
    
    Puppy.find({ likes: 'napping' }).exec().then(function (result) {
      console.log(result);
      mongodb.disconnect();
    }).catch(function (err) {
      console.log(err);
      mongodb.disconnect();
    });

  • Find One

    Puppy.findOne({ name: 'Sprinkles' }).exec().then(function (result) {
      console.log(result);
      mongodb.disconnect();
    }).catch(function (err) {
      console.log(err);
      mongodb.disconnect();
    });

  • Find By ID

    Puppy.findById('ID_HERE').then(function (result) {
      console.log(result);
      mongodb.disconnect();
    }).catch(function(err) {
      console.log(err);
      mongodb.disconnect();
    })

• Read Exercise
  • Create a new database called pets
  • Write a node script that will import all the puppies in the provided list into the database using Mongoose
    • Hint: Use Mongoose's insertMany method. Look up implementation info in their documentation
  • Create a small Express application that will return all the puppies from the database from a GET request
• Querying
  • Query Syntax
    • Individual

      var query = Puppy.find({ 'breed' : 'Dalmatian' });
      query.select('name age likes');
      query.limit(3);
      query.sort({ age: -1 });
      query.exec().then(function (result) {
        console.log(result);
        mongodb.disconnect();
      }).catch(function (err) {
        console.log(err);
        mongodb.disconnect();
      });

    • Chaining

      Puppy.find({ breed: 'Dalmatian' }).where('age').gt(2).sort({ age: -1 }).limit(2).exec().then(function(result) {
        console.log(result);
        mongodb.disconnect();
      }).catch(function(err) {
        console.log(err);
        mongodb.disconnect();
      });

• Update
  • Find then Update

    Puppy.findById('ID_HERE').then(function (puppy) {
      console.log(puppy);
      puppy.age = 4;
      return puppy.save();
    }).then(function (result) {
      console.log (result);
      mongodb.disconnect();
    }).catch(function(err) {
      console.log(err);
      mongodb.disconnect();
    });

  • Find One and Update

    Puppy.findOneAndUpdate({ breed: 'Dalmatian' }, { breed: 'Beagle' }).then(function (result) {
      return Puppy.findOne({ breed: 'Beagle' });
    }).then(function (result) {
      console.log(result);
      mongodb.disconnect();
    }).catch(function (err) {
      console.log(err);
      mongodb.disconnect();
    });

  • Find By ID and Update

    Puppy.findByIdAndUpdate('ID_HERE', { age: 5 }).then(function (result) {
      console.log(result);
      mongodb.disconnect();
    }).catch(function (err) {
      console.log(err);
      mongodb.disconnect();
    });

• Delete
  • Find then Delete

    Puppy.findById('ID_HERE').then(function (puppy) {
      console.log(puppy);
      return puppy.remove();
    }).then(function() {
      console.log('removed');
      mongodb.disconnect();
    }).catch(function (err) {
      console.log(err);
      mongodb.disconnect();
    });

  • Find One and Delete

    Puppy.findOneAndRemove({ breed: 'Dalmatian' }).then(function () {
      console.log('removed');
      mongodb.disconnect();
    }).catch(function (err) {
      console.log(err);
      mongodb.disconnect();
    });

  • Find By ID then Delete

    Puppy.findByIdAndRemove('ID_HERE').then(function () {
      console.log('removed');
      mongodb.disconnect();
    }).catch(function (err) {
      console.log(err);
      mongodb.disconnect();
    });

• Multiple Collections
  • Setup
    • Create a new database called library
    • Create a new node project
  • Author

    var mongoose = require('mongoose');
    
    var authorSchema = mongoose.Schema({
      firstname: String,
      lastname: String,
      books: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Book'}]
    });
    
    module.exports = mongoose.model('Author', authorSchema);

  • Book

    var mongoose = require('mongoose');
    
    var bookSchema = mongoose.Schema({
      title: String,
      author: { type: mongoose.Schema.Types.ObjectId, ref: 'Author' }
    });
    
    module.exports = mongoose.model('Book', bookSchema);

  • Index
    • Create Author

      function saveAuthor() {
        var shirleyJackson = new Author({
          firstname: 'Shirley',
          lastname:  'Jackson'
        });
      
        shirleyJackson.save().then(function (result) {
          console.log(result);
          mongodb.disconnect();
        }).catch(function (err) {
          throw err;
          mongodb.disconnect();
        });
      }
      
      saveAuthor();

    • Create Book

      function saveBook() {
      
        Author.find({ firstname: 'Shirley', lastname: 'Jackson' }).exec().then(function (authorResult) {
          console.log(authorResult);
          var shirleyJackson = authorResult[0];
          var weHaveAlways = new Book({
            title: 'We Have Always Lived in the Castle',
            author: shirleyJackson._id
          });
      
          return weHaveAlways.save();
        }).then(function (bookResult) {
          console.log(bookResult);
        }).catch(function (err) {
          console.log(err);
        });
      }
      
      saveBook()

  • Udpate Author to Add Book

    var bookFetched;
    Book.find({ title: 'We Have Always Lived in the Castle' }).exec().then(function (bookResult) {
      bookFetched = bookResult[0];
      return Author.find({ firstname: 'Shirley', lastname: 'Jackson' }).exec();
    }).then(function (authorResult) {
      var author = authorResult[0];
      author.books.push(bookFetched._id);
      return author.save();
    }).then(function (saveResult) {
      console.log(saveResult);
    }).catch(function (err) {
      console.log(err);
    });

  • Find Info

    Book.find({ title: 'We Have Always Lived in the Castle' }).exec().then(function(result) {
      console.log(result);
    }).catch(function(err) {
      console.log(err);
    });

    Book.find({ title: 'We Have Always Lived in the Castle' }).populate('author').exec().then(function(result) {
      console.log(result);
    }).catch(function(err) {
      console.log(err);
    });

• Multiple Collections Express Exercise