MongoDB Cheat Sheet

mongodb_cheat_sheet.md

MongoDB Cheat Sheet

Show All Databases

show dbs

Show Current Database

db

Create Or Switch Database

use acme

Drop

db.dropDatabase()

Create Collection

db.createCollection('posts')

Show Collections

show collections

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 Rows

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

Sort Rows

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

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)
})

Find One Row

db.posts.findOne({ 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'
  }
})

Increment Field ($inc)

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

Rename Field

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

Delete Row

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

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: 'text' })

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 } })

thank you!

Thank You!

Thanks sir

Thanks for this amazing documentation

I'm not sure why but the thing with text search by index doesn't work, I even tried to use the exact same commands as in this sheet, but on
db.posts.createIndex({ title: 'text' })
i get just
title_text
and then

db.friends.find({
    $text: {
        $search: "\"V\""
    }
})

gives me an empty line. I'm using the mongosh 1.6.2.0 version

Thanks for a great tutorial anyway

Small fixes I've made to this great document:
https://gist.github.com/hilako/d6217d7c64980eee424262a0d8ad0973
Thanks :-)

Nice

nice

Awesome thank you

thanks a lot :)

This help me a lot :)

Just plain and simple.. Loved it

nice

I am really thankful for living at this period of the history. Life by means of people like Brad is more beautiful.

Index Management:

MongoDB allows you to manage indexes to improve query performance. You can list and drop indexes on collections.

List Indexes:
db.posts.getIndexes()

Drop Index:
db.posts.dropIndex({ title: 1 })

Thanks!

good work

thank you

Very helpful, thanks!

thank you

Please do consider this too with some updates:
https://gist.github.com/ManasShettigar/4fb654b68136c040ae7bf2f7e489808c

very helpful for starter and hoping to have more resources from you THANK YOU!

thanks ypu brother

@phieraditya Thanks!

Thank you brother, amazing brief Sheet to understand the basics of MongoDB. Every work you produce is always amazing and professional in terms of its content. Thanks for everything.

nice its a good cheatsheet

I would add a second example to 'find' to specify which fields to retrieve. For example:
db.posts.find({ category: 'News' }, { title: true, body: true })

This is equivalent in SQL to:
SELECT title, body FROM posts WHERE category = 'News'

Adding update/delete examples using updateOne, updateMany, deleteOne, deleteMany with $set, and $unset.

1) UPDATE

• updateOne() modifies only the first matching document.
• updateMany() modifies all matching documents.
• $set: Updates (or adds) the specified fields.
• $unset: Removes the specified fields.

Update One:
db.posts.updateOne( { title: "Post One" }, { $set: { body: "Updated body for Post One" }, $unset: { category: "" } } );
Update Many:
db.posts.updateMany( { category: "News" }, { $set: { category: "Updated News" } } );

2) DELETE

• deleteOne() removes only the first matching document.
• deleteMany() removes all matching documents.

Delete One:
db.posts.deleteOne( { title: "Post Four" } );
Delete Many
db.posts.deleteMany( { category: "Entertainment" } );

1) Comparison operator examples:

$ne (Not equals) - Find documents where 'category' is NOT 'News':
db.posts.find({ category: { $ne: "News" } });

$in (Matches Any Of) - Find documents where 'category' is either 'News' OR 'Technology':
db.posts.find({ category: { $in: ["News", "Technology"] } });

$nin (Not In) - Find documents where 'category' is neither 'News' nor 'Technology':
db.posts.find({ category: { $nin: ["News", "Technology"] } });

2) Logical operator examples:

$and (Matches All) - Find documents where 'category' is "News" AND 'user.name' is "John Doe":
db.posts.find({ $and: [ { category: "News" }, { "user.name": "John Doe" } ] });

$nor (Matches None) - Find documents where 'category' is neither "News" NOR "Technology":
db.posts.find({ $nor: [ { category: "News" }, { category: "Technology" } ] });

$or (Matches Any) - Find documents where 'category' is "News" OR "Technology":
db.posts.find({ $or: [ { category: "News" }, { category: "Technology" } ] });

$not (With $lte & $regex) - Find documents where 'views' is NOT less than or equal to 100 (i.e., greater than 100), and the 'title' does not start with "Post":
db.posts.find({ $and: [ { views: { $not: { $lte: 100 } } }, { title: { $not: /^Post/ } } ] });

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