Atlas Dashboard

connect

Connect Dialog

options

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after a successful connection establishment you will face a session with a prompt like the following:

Atlas atlas-sefmue-shard-0 [primary] test>

Basic Sampling

list databases

show dbs

use a database

use my-db

if the shahar-db doesn’t exist then it will be created after you add data in it

list collections

show collections

to drop the used db run (require user permissions):

db.dropDatabase()

Inserting Documents

use pita
db.users.insertOne({ name: "nisim" })

after running it a pita db will be created with a users collection with the document: { name: “nisim” }

Print All Rows

use pita
db.users.insertOne({ name: "nisim" })
db.users.insertOne({ name: "shlomo" })
db.users.insertOne({ name: "david" })
db.users.find()

output:

[
  { _id: ObjectId("64..."), name: 'nisim' },
  { _id: ObjectId("64..."), name: 'shlomo' },
  { _id: ObjectId("64..."), name: 'david' }
]

different forms of documents in the same collection is allowed

db.users.insertOne({ name: "bamba" })
db.users.insertOne({ name: "bisli", age: 42 })

nesting objects in document

db.users.insertOne({
	name: "gargamel",
	age: 900,
	address: {
		city: "Tel-Aviv",
		street: "Alenbi"
	}
})

array value

db.users.insertOne({
	name: "elvis"
	favouriteSingers: [
		"avi biter",
		"shimi tavori"
	]
})

insert multiple docs

db.users.insertMany([
	{ name: "nisim" },
	{ name: "shlomo" },
	{ name: "david" }
])

Limit and Skip

show only the first two

db.users.find().limit(2)

skip first 3

db.users.find().skip(3)

Filtering Fields

hide some properties

db.users.find({}, { name: 1, isAwesome: 1 })
db.users.find({}, { name: 1, isAwesome: 1, address: 1 })

hide id

db.users.find({}, { name: 1, isAwesome: 1, _id: 0 })

show all except for

db.users.find({}, { age: 0 })
db.users.find({}, { name:0, age: 0 })

Filtering Documents

name equal to “nisim”

db.users.find({ name: { $eq: "nisim" } })

name not equal to “nisim”

db.users.find({ name: { $ne: "nisim" } })

Comparison

mongo literally meaning
$gt greater then >
$gte greater then equal ≥
$lt less then <
$lte less then equal ≤

age > 42

db.users.find({ age: { $gt: 42 } })

age ≥ 42

db.users.find({ age: { $gte: 42 } })

age < 42

db.users.find({ age: { $lt: 42 } })

age ≤ 42

db.users.find({ age: { $lte: 42 } })

in

name is “nisim” or “shlomo”

db.users.find({ name: { $in: ["nisim", "shlomo"] } })

name is not “nisim” or “shlomo”

db.users.find({ name: { $nin: ["nisim", "shlomo"] } })

has properties

all documents that have the age property

db.users.find({ age: { $exists: true } })

all documents that don’t have the age property

db.users.find({ age: { $exists: false } })

db.users.insertOne({ name: "avi biter", age: null })

in this case “avi biter” document has the age property

“and” Conditions

multiple conditions

db.users.find({
	name: { $nin: ["nisim", "shlomo"] },
	age: { $gt: 42 }
})

multiple conditions for the same property

20 < age < 40

db.users.find({ age: { $gt: 20, $lt: 40 } })

another way (not useful)

db.users.find({ $and: [
	{ age: 26 },
	{ name: "nisim" }
] })

The same but “or” condition

age === 42 or name === “nisim”

db.users.find({ $or: [
	{ age: 26 },
	{ name: "nisim" }
] })

age < 42 or name === “nisim”

db.users.find({ $or: [
	{ age: { $lt: 42 } },
	{ name: "nisim" }
] })

Not

db.users.find({ age: { $not: { $gt: 20 } } })

Compare two properties in the same doc

get all those who’s balance > debt

db.users.insertMany([
	{ name: "nisim", balance: 200, debt: 100 },
	{ name: "shlomo", balance: 300, debt: 200 },
	{ name: "david", balance: 5, debt: 999 },
])

$expr

db.users.find({ $expr: { $gt: ["$balance", "$debt"] } })

Find by nested

all who live in “Tel Aviv”

db.users.insertMany([
	{
		name: "nisim",
		address: { city: "Tel Aviv" }
	},
	{
		name: "shlomo",
		address: { city: "Tel Aviv" }
	},
	{
		name: "david",
		address: { city: "Jerusalem" }
	}
])

Dot (.) Operator

db.users.find({ "address.city": "Tel Aviv" })

Count

query by condition

db.users.find({ balance: { $gt: 250 } })

count it

db.users.countDocuments({ balance: { $gt: 250 } })

Sorting

ascending

db.users.find().sort({ name: 1 })

descending

db.users.find().sort({ name: -1 })

sort by multiple categories

db.users.find().sort({ age: 1, name: -1 })

Update

update a single

will update the first document that follow the given condition

db.users.updateOne({ age: 26 }, { $set: { age: 27 } })

mostly we will use the id

db.users.updateOne({ _id: ObjectId("12345...") }, { $set: { name: "avi biter" } })

increment

db.users.updateOne({ _id: ObjectId("12345...") }, { $inc: { age: 3 } })

rename property

db.users.updateOne({ _id: ObjectId("12345...") }, { $rename: { name: "fullName" } })

unset property

db.users.updateOne({ _id: ObjectId("12345...") }, { $unset: { age: "" } })

push element to array property

db.users.updateOne({ _id: ObjectId("12345...") }, { $push: { hobbies: "chess" } })

pull element from array property

db.users.updateOne({ _id: ObjectId("12345...") }, { $pull: { hobbies: "pentagon breaking" } })

update many

update all documents that follow the given condition

db.users.updateMany({ address: { $exists: true } }, { $unset: { address: "" } })

Delete

delete one doc

delete the first document that follow the given condition

db.users.deleteOne({ _id: ObjectId("12345...") })
db.users.deleteOne({ name: "shimi" })

delete many docs

delete all the documents that follow the given condition

db.users.deleteMany({ age: { $exists: true } })