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Kamal Hossain
Kamal Hossain

Posted on • Updated on

MongoDB Cheat Sheet

MongoDB Cheat Sheet

Open MongoDB in cmd (For windows)

mongo
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If mongo is not recognized as an internal or external command, operable program or batch file, then do the followings from this blog

Show All Databases

show dbs
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Show Current Database

db
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Create Or Switch Database

use acme
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Drop DatabaseπŸ”΄

> use mydb
> db.dropDatabase()
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Create Collection

db.createCollection('posts')
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Show Collections

show collections
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Drop Collection πŸ”΄

> use mydb
> db.usersCollection.drop()
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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()
})
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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()
  }
])
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Get All Rows from a collection

db.posts.find()
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Get All Rows from a collection Formatted

db.posts.find().pretty()
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Find Rows

db.posts.find({ category: 'News' })
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Sort Rows in a collection

# asc
db.posts.find().sort({ title: 1 }).pretty()
# desc
db.posts.find().sort({ title: -1 }).pretty()
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Count Rows in a collection

db.posts.find().count()
db.posts.find({ category: 'news' }).count()
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Limit Rows in a collection

db.posts.find().limit(2).pretty()
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Chaining example

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

db.posts.find().forEach(function(doc) {
  print("Blog Post: " + doc.title)
})
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Find One Row

db.posts.findOne({ category: 'News' })
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Find Specific Fields

db.posts.find({ title: 'Post One' }, {
  title: 1,
  author: 1
})
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Update Row

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

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

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

db.posts.update({ title: 'Post Two' },
{
  $rename: {
    likes: 'views'
  }
})
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Delete specific document from a collection

db.posts.remove({ title: 'Post Four' })
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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()
      }
    ]
  }
})
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Find By Element in Array (\$elemMatch)

db.posts.find({
  comments: {
     $elemMatch: {
       user: 'Mary Williams'
       }
    }
  }
)
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Add Index

db.posts.createIndex({ title: 'text' })
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Text Search

db.posts.find({
  $text: {
    $search: "\"Post O\""
    }
})
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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 } })
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Get database size and index size in MB (Megabytes)

db.stats(1024*1024);
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Export a collection in json format

mongoexport --db newdb -c usersCollection --out testBakcup.json
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Import a collection from json file

mongoimport --db newdb -c usersCollectiontwo --file test.json
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Export entire database including all collections (Local)

mongodump --db newdb
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Export entire database including all collections (Cluster)

mongodump --uri="mongodb+srv://<Name>:<Password>@cluster0-pk6qf.mongodb.net/<DB_YOU_WANT_TO_EXPORT>?retryWrites=true&w=majority"
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ref1

use --collection <collection_name> for only specific collection

Import entire database including all collections

mongorestore --db deleteme dump/newdb
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newdb is the folder name that holds the database (deleteme) related files (.bson) etc.
To override same document with _id use this method

Connect to cloud mongodb cluster from mongo shell

mongo "mongodb+srv://cluster0.g1re8.mongodb.net/<dbname>" --username <check_mongo_cloud_connect_shell>
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Useful resources

Posted in β€’ dev.to β€’ gist.github.com

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