The Magical Marvels of MongoDB - Code Companion

gistfile1.js

//************************************
//
//  Level 1 concepts
//
//************************************

// Basic data model (BSON)

{
  _id: 1,
  name: "Magical Database Dust",
  price: 25,
  ingredients: ["magic", "a grandmother's sneeze"]
}

// Select which database to use
use potion_shop

//-----------------------------
//  Create
//    -> db.collection.insert()
//-----------------------------

// Adding a potion to the inventory collection 
db.inventory.insert({
  _id: 1,
  name: "Magical Database Dust",
  price: 25,
  ingredients: ["magic", "a grandmother's sneeze"]
})

// View inventory
db.inventory.find()

//----------------------------
//  Update
//   -> db.collection.update()
//----------------------------

// Whoops! We entered the wrong price. We need to update all the prices that are 25
// and make them 25.99 (We could use Regex to update all that don't have .99)
db.inventory.update(
  { price: 25  },
  { $set: { price: 25.99 } },
  { multi: true }
)

// A new law has passed, only wizards who are 18+ can purchase potions that contain dragon tongue.
db.inventory.update(
  { ingredients: {$in: "Dragon tongue" } }, // What's cool is we can add as many query operators as we want.
  { $set: { age_limit: 18 } },
  { multi: true }
)  

// Upsert - this is esentially find or create. Use case can be a newsletter announcing new potions.
// GOTCHA! Only do this on keys that have a unique index.
db.inventory.update(
  { email: "funny_reference@somthing_magical.com" },
  { email: "funny_reference@somthing_magical.com",
    name: "Harry Potter",
    age: 10
  },
  { upsert: true }
)  

// Removing fields - we no longer need age restrictions on dragon tongue.
db.inventory.update( { ingredients: {$in: "Dragon tongue"} }, { $unset: { age: 1 } } )

//----------------------------
//  Remove
//   -> db.collection.remove()
//----------------------------

// Whoops! Now Dragon tongue is considered a Schedule 1 narcotic! Better remove it
// before the WBI arrests us.
db.inventory.remove({ingredients:{$in: "Dragon tongue"}})