mongodb

Cheatsheet for mongodb

Mongodb

# *****************************************************************************
# BASICS
# *****************************************************************************

# Connect MongoDB Shell
mongo # connects to mongodb://127.0.0.1:27017 by default
mongo --host <host> --port <port> -u <user> -p <pwd> # omit the password if you want a prompt

# Show All Databases
show dbs


# Show Current Database
db


# Create Or Switch Database
use <database_name>


# Drop Database
db.dropDatabase()


# Create Collection
db.createCollection('posts')


# Show Collections
show collections


# *****************************************************************************
# CRUD
# *****************************************************************************

# Insert Row
db.posts.insert({
  title: 'Post One',
  body: 'Body of post one',
  category: 'News',
  tags: ['news', 'events'],
  user: {
    name: 'John Doe',
    status: 'author'
  },
  date: Date()
})


# Insert Multiple Rows
db.posts.insertMany([
  {
    title: 'Post Two',
    body: 'Body of post two',
    category: 'Technology',
    date: Date()
  },
  {
    title: 'Post Three',
    body: 'Body of post three',
    category: 'News',
    date: Date()
  },
  {
    title: 'Post Four',
    body: 'Body of post three',
    category: 'Entertainment',
    date: Date()
  }
])


# Get All Rows
db.posts.find()


# Get All Rows Formatted
db.posts.find().pretty()


# Find One Row
db.posts.findOne({ category: 'News' })


# Find Rows
db.posts.find({ category: 'News' })


# Find Specific Fields
db.posts.find({ title: 'Post One' }, {
  title: 1,
  author: 1
})


# Update Row
db.posts.update({ title: 'Post Two' },
{
  title: 'Post Two',
  body: 'New body for post 2',
  date: Date()
},
{
  upsert: true
})


# Update Specific Field
db.posts.update({ title: 'Post Two' },
{
  $set: {
    body: 'Body for post 2',
    category: 'Technology'
  }
})


# Delete Row
db.posts.remove({ title: 'Post Four' })


# *****************************************************************************
# OTHER FUNCTIONS
# *****************************************************************************

# Sort Rows
db.posts.find().sort({ title: 1 }).pretty() # asc
db.posts.find().sort({ title: -1 }).pretty() # desc


# Count Rows
db.posts.find().count()
db.posts.find({ category: 'news' }).count()


# Limit Rows
db.posts.find().limit(2).pretty()


# Chaining
db.posts.find().limit(2).sort({ title: 1 }).pretty()


# Foreach
db.posts.find().forEach(function(doc) {
  print("Blog Post: " + doc.title)
})


# Increment Field (\$inc)
db.posts.update({ title: 'Post Two' },
{
  $inc: {
    likes: 5
  }
})


# Rename Field
db.posts.update({ title: 'Post Two' },
{
  $rename: {
    likes: 'views'
  }
})


# Sub-Documents
db.posts.update({ title: 'Post One' },
{
  $set: {
    comments: [
      {
        body: 'Comment One',
        user: 'Mary Williams',
        date: Date()
      },
      {
        body: 'Comment Two',
        user: 'Harry White',
        date: Date()
      }
    ]
  }
})


# Find By Element in Array (\$elemMatch)
db.posts.find({
  comments: {
     $elemMatch: {
       user: 'Mary Williams'
       }
    }
  }
)


# Add Index
db.posts.createIndex({ title: 1 })


# Drop Index
db.posts.dropIndex("title_1")


# Hide/Unhide Indexes
db.posts.hideIndex("title_1")
db.posts.unhideIndex("title_1")


# Text Search
db.posts.find({
  $text: {
    $search: "\"Post O\""
    }
})


# Greater & Less Than
db.posts.find({ views: { $gt: 2 } })
db.posts.find({ views: { $gte: 7 } })
db.posts.find({ views: { $lt: 7 } })
db.posts.find({ views: { $lte: 7 } })