Show list of databases

show databases OR show dbs

Show list of collections

show collections

Create or switch between databases

use database_name

Create collection

db.createCollection('collection_name')

insert document

you can define variable (js syntax) and pass it as excepted parameter.

var user = {
  name: "Mohammad MohammadAlian",
  ip: "127.0.0.1",
  lastLoginTime: 1575704736
};

db.insertOne(user);

OR

db.collection.insertOne({name: 'Mohammad MohammadAlian', ip: '127.0.0.1', lastLoginTime: 1575704736});

to insert many object in one query you can use insertMany function

var users = [
  {
    name: "Mohammad MohammadAlian",
    ip: "127.0.0.1",
    lastLoginTime: 1575704736
  },
  { name: "John Doe", ip: "10.10.10.10", lastLoginTime: 1575704965 }
];

db.insertMany(users);

OR

db.collection.insertMany([{name: 'Mohammad MohammadAlian', ip: '127.0.0.1', lastLoginTime: 1575704736}, {name: 'John Doe', ip: '10.10.10.10', lastLoginTime: 1575704965}]);

Querying

find

retrieve all of documents

db.collection.find() OR db.collection.find({})

query by value of specific field

db.collection.find({name: 'Mohammad MohammadAlian'})

querying throw nested field

var user = { name: "John", job: { title: "programmer", salary: 125000 } };

if we want to find above user by job title we could use following command

db.collection.find({'job.title': 'programmer'})

using regex

db.collection.find({name: /M.*/})

pretty

make results pretty 😁

db.collection.find().pretty()

limit

db.collection.find().limit(10)

NOTE: 10 is count of documents which will be retrieved

skip

skip result

db.collection.find().skip(2)

NOTE: 2 is count of documents which will be skipped

sort

show sorted result

db.collection.find().sort({fieldName: 1})

NOTE: 1 is ascending and -1 is descending

count

retrieve count of results

db.collection.find().count()

distinct

retrieve distinct value

db.collection.distinct('name')

NOTE: name is a field

for nested field we can use following command

db.collection.distinct('comments.message')

Operators

less than

db.collection.find({field: {$lt: 200}})

less than or equal

db.collection.find({field: {$lte: 200}})

greater than

db.collection.find({field: {$gt: 200}})

greater than or equal

db.collection.find({field: {$gte: 200}})

not equal

db.collection.find({field: {$ne: 'string is also accepted in some operators'}})

in

db.collection.find({field: {$in: [1999,2010,2019,2022]}})

all

db.collection.find({field: {$all: [1999,2010]}})

slice

db.collection.find({arrayField: {$slice: 3}})

or

db.collection.find({$or: [{filed: 'value'}, {field: 'value'}]})

mod

modulo operator db.collection.find({field: {$mod: [100,0]}})

size

db.collection.find({arrayFiled: {$size: 2}})

exists

db.collection.find({field: {$exists: true}})

type

type numbers db.collection.find({field: {$type: 2}})

Update document

general form

db.collection.update({query}, {update}, {flags})

example

db.collection.update({field: 'value'}, {$set: {otherField: 'new Value'}}, {upsert: true})

inc

increment value

db.collection.updateOne({field: 'value'}, {$inc: {number: 6}})

Increases six units of number

unset

db.collection.updateOne({field: 'value'}, {$unset: {anotherField: 1}})

this will be remove anotherField where field equal value

push

push value to array

db.collection.updateOne({_id: 1}, {$push: {numbers: 6}})

push six into numbers where id is 1

each

db.collection.updateOne({_id: 1}, {$push:{numbersArray: {$each: ['R','T', 'H']}}})

add each value to numbersArray where id is 1

addToSet

push to array if not exists

db.collection.updateOne({_id:1}, {$addToSet: {numbers: 565}})

pop

db.collection.updateOne({_id: 1}, {$pop: {numbers: -1}}) 1: from end -1: from beginning

pull

db.collection.updateOne({_id: 1}, {$pull: {numbers: 5}})

remove all 5 in numbers Array where id is 1

pullAll

db.collection.updateOne({_id: 1}, {$pullAll: {numbers: [4,5,6]}})

rename collection

db.collection.renameCollection('newCollectionName')

delete document

db.collection.deleteOne({_id: 1})

delete collection

db.collection.drop()

delete database

db.dropDatabase()

Create Index

db.collection.createIndex({field: 1}) NOTE: 1 is ascending and -1 is descending

create text index db.collection.createIndex({field: 'text'})

Drop Index

db.collection.dropIndex({field: 1})

Aggregate

db.collection.aggregate({ $group: {_id: '$color'} })

db.collection.aggregate({ $group: {_id: '$color', count: {$sum: 1}} })

db.aggregation.aggregate({ $group: {_id: "$color"} });

db.aggregation.aggregate([ {$match: {num: {$gt: 500}}}, {$group: {_id: '$color', count: {$sum: 1}}}, {$limit: 5} ]);

db.aggregation.aggregate([ {$match: {num: {$gt: 500}}}, {$sort: {color: 1}} ]);

db.aggregation.aggregate({ $unwind: "$vegetables" });

db.aggregation.aggregate([ {$match: {num: {$gt: 500}}}, {$project: {_id:0, fruits: 0}}, {$skip: 200}, {$out: "newCollectionGeneratedByAggregationFramework"} ]);

db.prima.aggregate({ \$lookup: { from: 'secunda', localField: 'number', foreignField: 'number', as: 'doc' } });