Table of Contents for

React Quickly: Painless web apps with React, JSX, Redux, and GraphQL

Appendix D. MongoDB and Mongoose cheatsheet

When you develop your own projects, searching on the internet for React documentation and APIs or going back to this book’s chapters to find a single method isn’t efficient. If you’d like to save time and avoid the distractions lurking everywhere on the Net, use this MongoDB cheatsheet as a quick reference.

MongoDB

• $ mongod—Starts the MongoDB server (localhost:27017)
• $ mongo (connects to the local server by default)—Opens the MongoDB console

MongoDB console

• > show dbs—Shows databases on the server
• > use DB_NAME—Selects the database DB_NAME
• > show collections—Shows collections in the selected database
• > db.COLLECTION_NAME.find()—Performs a find query on the collection named COLLECTION_NAME to find any items
• > db.COLLECTION_NAME.find({"_id"—ObjectId("549d9a3081d0f07866fdaac6") })—Performs a find query on the collection named COLLECTION_NAME to find the item with ID 549d9a3081d0f07866fdaac6
• > db.COLLECTION_NAME.find({"email": /gmail/})—Performs a find query on the collection named COLLECTION_NAME to find items with an email property matching /gmail
• > db.COLLECTION_NAME.update(QUERY_OBJECT, SET_OBJECT)—Performs an update query on the collection named COLLECTION_NAME to update items that match QUERY_OBJECT with SET_OBJECT
• > db.COLLECTION_NAME.remove(QUERY_OBJECT)—Performs a remove query for items matching QUERY_OBJECT criteria on the COLLECTION_NAME collection
• > db.COLLECTION_NAME.insert(OBJECT)—Adds OBJECT to the collection named COLLECTION_NAME

Installing Mongoose

• $ sudo npm install mongoose—Installs the latest version of Mongoose locally
• $ sudo npm install mongoose@3.8.20 --save—Installs Mongoose v3.8.20 locally, and saves it to package.json

Mongoose basic usage

var mongoose = require('mongoose')
var dbUri = 'mongodb://localhost:27017/api'
var dbConnection = mongoose.createConnection(dbUri)
var Schema = mongoose.Schema
var postSchema = new Schema ({
  title: String,
  text: String
})
var Post = dbConnection.model('Post', postSchema, 'posts')
Post.find({},function(error, posts){
  console.log(posts)
  process.exit(1)
})

Mongoose schema

• String
• Boolean
• Number
• Date
• Array
• Buffer
• Schema.Types.Mixed
• Schema.Types.ObjectId

Create, read, update, delete (CRUD) Mongoose example

// Create
var post = new Post({title: 'a', text: 'b')
post.save(function(error, document){
  ...
})
// Read
Post.findOne(criteria, function(error, post) {
  ...
})
// Update
Post.findOne(criteria, function(error, post) {
  post.set()
  post.save(function(error, document){
    ...
  })
})
// Delete
Post.findOne(criteria, function(error, post) {
  post.remove(function(error){
    ...
  })
})

Mongoose model methods

• find(criteria, [fields], [options], [callback]), where callback has error and documents arguments—Finds a document
• count(criteria, [callback])), where callback has error and count arguments—Returns a count of documents with matching criteria
• findById(id, [fields], [options], [callback]), where callback has error and document arguments—Returns a single document by ID
• findByIdAndUpdate(id, [update], [options], [callback])—Executes MongoDB’s findAndModify() to update a document by ID
• findByIdAndRemove(id, [options], [callback])—Executes MongoDB’s findAndModify() to remove a document by ID
• findOne(criteria, [fields], [options], [callback]), where callback has error and document arguments—Returns a single document
• findOneAndUpdate([criteria], [update], [options], [callback])—Executes MongoDB’s findAndModify() to update document(s)
• findOneAndRemove(id, [update], [options], [callback])—Executes MongoDB’s findAndModify() to remove a document
• update(criteria, update, [options], [callback]), where callback has error and count arguments—Updates documents
• create(doc(s), [callback]), where callback has error and doc(s) arguments—Creates a document object, and saves it to the database
• remove(criteria, [callback]), where callback has an error argument—Removes documents

Mongoose document methods

• save([callback]), where callback has error, doc, and count arguments—Saves the document
• set(path, val, [type], [options])—Sets a value on the document’s property
• get(path, [type])—Gets the value of a property
• isModified([path])—Checks whether a property has been modified
• populate([path], [callback])—Populates a reference
• toJSON(options)—Gets JSON from the document
• validate(callback)—Validates the document