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readme.md

Databases

Intro to Databases

  • What is a database?
    • A Collection of information / data
    • Has an interface
  • SQL (Relational) vs NoSQL (Non-Relational)

SQL Example

Users Table

Id Name Age City
1 John 24 Denver
2 Tim 32 NYC

Comments Table

Id Text
1 "Lol"
2 "Cool Picture!"

User / Comment Join Table

UserId CommentId
1 1

NoSQL Example

Looks like JSON, but is BSON (Binary JSON)

{
  Name: "Kevin",
  Age: 17,
  City: Chicago,
  Comments: [
    {text: "Lol"},
    {text: "Cool Picture!"}
  ]
}

Important Mongo Commands

  • mongod
  • mongo
  • help
  • show dbs
  • use
  • insert
    • Example: db.dogs.insert({name: "Tux", breed: "Yorkie-Poodle"})
  • find
    • Example: db.dogs.find()
      • db.dogs.find({name: "Tux"})
  • update
    • Example: db.dogs.update({name:"Tux"}, {breed: "Poodle"})
      • The line above will find a dog named Tux, and update his information so that it only contains breed = Poodle. If we wanted to update Tux so that we just update his breed, use the code found below.
    • Example: db.dogs.update({name: "Tux"}, {$set: {breed: "Poodle"}})
      • This will preserve Tux's name, and update just the breed.
  • remove
    • Example: db.dogs.remove({breed: "Poodle"})
      • Remove everything that matches

Mongoose

  • What is Mongoose?
  • Why are we using it?
  • Interact with Mongo Database using Mongoose