MongoDB Cheat Sheet

1
mongosh # connects to mongodb://127.0.0.1:27017 by default
2
mongosh --host <host> --port <port> --authenticationDatabase admin -u <user> -p <pwd> # omit the password if you want a prompt
3
mongosh "mongodb://<user>:<password>@192.168.1.1:27017"
4
mongosh "mongodb://192.168.1.1:27017"
5
mongosh "mongodb+srv://cluster-name.abcde.mongodb.net/<dbname>" --apiVersion 1 --username <username> # MongoDB Atlas

1
show dbs
2
db // prints the current database

1
use <database_name>

1
show collections

1
load("myScript.js")

1
db.coll.insertOne({name: "Max"})
2
db.coll.insertMany([{name: "Max"}, {name:"Alex"}]) // ordered bulk insert
3
db.coll.insertMany([{name: "Max"}, {name:"Alex"}], {ordered: false}) // unordered bulk insert
4
db.coll.insertOne({date: ISODate()})
5
db.coll.insertOne({name: "Max"}, {"writeConcern": {"w": "majority", "wtimeout": 5000}})

1
db.coll.findOne() // returns a single document
2
db.coll.find()    // returns a cursor - show 20 results - "it" to display more
3
db.coll.find().pretty()
4
db.coll.find({name: "Max", age: 32}) // implicit logical "AND".
5
db.coll.find({date: ISODate("2020-09-25T13:57:17.180Z")})
6
db.coll.find({name: "Max", age: 32}).explain("executionStats") // or "queryPlanner" or "allPlansExecution"
7
db.coll.distinct("name")
8
9
// Count
10
db.coll.countDocuments({age: 32}) // alias for an aggregation pipeline - accurate count
11
db.coll.estimatedDocumentCount()  // estimation based on collection metadata
12
13
// Comparison
14
db.coll.find({"year": {$gt: 1970}})
15
db.coll.find({"year": {$gte: 1970}})
16
db.coll.find({"year": {$lt: 1970}})
17
db.coll.find({"year": {$lte: 1970}})
18
db.coll.find({"year": {$ne: 1970}})
19
db.coll.find({"year": {$in: [1958, 1959]}})
20
db.coll.find({"year": {$nin: [1958, 1959]}})
21
22
// Logical
23
db.coll.find({name:{$not: {$eq: "Max"}}})
24
db.coll.find({$or: [{"year" : 1958}, {"year" : 1959}]})
25
db.coll.find({$nor: [{price: 1.99}, {sale: true}]})
26
db.coll.find({
27
  $and: [
28
    {$or: [{qty: {$lt :10}}, {qty :{$gt: 50}}]},
29
    {$or: [{sale: true}, {price: {$lt: 5 }}]}
30
  ]
31
})
32
33
// Element
34
db.coll.find({name: {$exists: true}})
35
db.coll.find({"zipCode": {$type: 2 }})
36
db.coll.find({"zipCode": {$type: "string"}})
37
38
// Aggregation Pipeline
39
db.coll.aggregate([
40
  {$match: {status: "A"}},
41
  {$group: {_id: "$cust_id", total: {$sum: "$amount"}}},
42
  {$sort: {total: -1}}
43
])
44
45
// Text search with a "text" index
46
db.coll.find({$text: {$search: "cake"}}, {score: {$meta: "textScore"}}).sort({score: {$meta: "textScore"}})
47
48
// Regex
49
db.coll.find({name: /^Max/})   // regex: starts by letter "M"
50
db.coll.find({name: /^Max$/i}) // regex case insensitive
51
52
// Array
53
db.coll.find({tags: {$all: ["Realm", "Charts"]}})
54
db.coll.find({field: {$size: 2}}) // impossible to index - prefer storing the size of the array & update it
55
db.coll.find({results: {$elemMatch: {product: "xyz", score: {$gte: 8}}}})
56
57
// Projections
58
db.coll.find({"x": 1}, {"actors": 1})               // actors + _id
59
db.coll.find({"x": 1}, {"actors": 1, "_id": 0})     // actors
60
db.coll.find({"x": 1}, {"actors": 0, "summary": 0}) // all but "actors" and "summary"
61
62
// Sort, skip, limit
63
db.coll.find({}).sort({"year": 1, "rating": -1}).skip(10).limit(3)
64
65
// Read Concern
66
db.coll.find().readConcern("majority")

1
db.coll.updateOne({"_id": 1}, {$set: {"year": 2016, name: "Max"}})
2
db.coll.updateOne({"_id": 1}, {$unset: {"year": 1}})
3
db.coll.updateOne({"_id": 1}, {$rename: {"year": "date"} })
4
db.coll.updateOne({"_id": 1}, {$inc: {"year": 5}})
5
db.coll.updateOne({"_id": 1}, {$mul: {price: NumberDecimal("1.25"), qty: 2}})
6
db.coll.updateOne({"_id": 1}, {$min: {"imdb": 5}})
7
db.coll.updateOne({"_id": 1}, {$max: {"imdb": 8}})
8
db.coll.updateOne({"_id": 1}, {$currentDate: {"lastModified": true}})
9
db.coll.updateOne({"_id": 1}, {$currentDate: {"lastModified": {$type: "timestamp"}}})
10
11
// Array
12
db.coll.updateOne({"_id": 1}, {$push :{"array": 1}})
13
db.coll.updateOne({"_id": 1}, {$pull :{"array": 1}})
14
db.coll.updateOne({"_id": 1}, {$addToSet :{"array": 2}})
15
db.coll.updateOne({"_id": 1}, {$pop: {"array": 1}})  // last element
16
db.coll.updateOne({"_id": 1}, {$pop: {"array": -1}}) // first element
17
db.coll.updateOne({"_id": 1}, {$pullAll: {"array" :[3, 4, 5]}})
18
db.coll.updateOne({"_id": 1}, {$push: {"scores": {$each: [90, 92]}}})
19
db.coll.updateOne({"_id": 2}, {$push: {"scores": {$each: [40, 60], $sort: 1}}}) // array sorted
20
db.coll.updateOne({"_id": 1, "grades": 80}, {$set: {"grades.$": 82}})
21
db.coll.updateMany({}, {$inc: {"grades.$[]": 10}})
22
db.coll.updateMany({}, {$set: {"grades.$[element]": 100}}, {multi: true, arrayFilters: [{"element": {$gte: 100}}]})
23
24
// FindOneAndUpdate
25
db.coll.findOneAndUpdate({"name": "Max"}, {$inc: {"points": 5}}, {returnNewDocument: true})
26
27
// Upsert
28
db.coll.updateOne({"_id": 1}, {$set: {item: "apple"}, $setOnInsert: {defaultQty: 100}}, {upsert: true})
29
30
// Replace
31
db.coll.replaceOne({"name": "Max"}, {"firstname": "Maxime", "surname": "Beugnet"})
32
33
// Write concern
34
db.coll.updateMany({}, {$set: {"x": 1}}, {"writeConcern": {"w": "majority", "wtimeout": 5000}})

1
db.coll.deleteOne({name: "Max"})
2
db.coll.deleteMany({name: "Max"}, {"writeConcern": {"w": "majority", "wtimeout": 5000}})
3
db.coll.deleteMany({}) // WARNING! Deletes all the docs but not the collection itself and its index definitions
4
db.coll.findOneAndDelete({"name": "Max"})

1
db.coll.drop()    // removes the collection and its index definitions
2
db.dropDatabase() // double check that you are *NOT* on the PROD cluster... :-)

1
// Create collection with a $jsonschema
2
db.createCollection("contacts", {
3
   validator: {$jsonSchema: {
4
      bsonType: "object",
5
      required: ["phone"],
6
      properties: {
7
         phone: {
8
            bsonType: "string",
9
            description: "must be a string and is required"
10
         },
11
         email: {
12
            bsonType: "string",
13
            pattern: "@mongodb\.com$",
14
            description: "must be a string and match the regular expression pattern"
15
         },
16
         status: {
17
            enum: [ "Unknown", "Incomplete" ],
18
            description: "can only be one of the enum values"
19
         }
20
      }
21
   }}
22
})

1
db.coll.stats()
2
db.coll.storageSize()
3
db.coll.totalIndexSize()
4
db.coll.totalSize()
5
db.coll.validate({full: true})
6
db.coll.renameCollection("new_coll", true) // 2nd parameter to drop the target collection if exists

1
db.coll.getIndexes()
2
db.coll.getIndexKeys()

1
// Index Types
2
db.coll.createIndex({"name": 1})                // single field index
3
db.coll.createIndex({"name": 1, "date": 1})     // compound index
4
db.coll.createIndex({foo: "text", bar: "text"}) // text index
5
db.coll.createIndex({"$**": "text"})            // wildcard text index
6
db.coll.createIndex({"userMetadata.$**": 1})    // wildcard index
7
db.coll.createIndex({"loc": "2d"})              // 2d index
8
db.coll.createIndex({"loc": "2dsphere"})        // 2dsphere index
9
db.coll.createIndex({"_id": "hashed"})          // hashed index
10
11
// Index Options
12
db.coll.createIndex({"lastModifiedDate": 1}, {expireAfterSeconds: 3600})      // TTL index
13
db.coll.createIndex({"name": 1}, {unique: true})
14
db.coll.createIndex({"name": 1}, {partialFilterExpression: {age: {$gt: 18}}}) // partial index
15
db.coll.createIndex({"name": 1}, {collation: {locale: 'en', strength: 1}})    // case insensitive index with strength = 1 or 2
16
db.coll.createIndex({"name": 1 }, {sparse: true})

1
db.coll.dropIndex("name_1")

1
db.coll.hideIndex("name_1")
2
db.coll.unhideIndex("name_1")

1
use admin
2
db.createUser({"user": "root", "pwd": passwordPrompt(), "roles": ["root"]})
3
db.dropUser("root")
4
db.auth( "user", passwordPrompt() )
5
6
use test
7
db.getSiblingDB("dbname")
8
db.currentOp()
9
db.killOp(123) // opid
10
11
db.fsyncLock()
12
db.fsyncUnlock()
13
14
db.getCollectionNames()
15
db.getCollectionInfos()
16
db.printCollectionStats()
17
db.stats()
18
19
db.getReplicationInfo()
20
db.printReplicationInfo()
21
db.hello()
22
db.hostInfo()
23
24
db.shutdownServer()
25
db.serverStatus()
26
27
db.getProfilingStatus()
28
db.setProfilingLevel(1, 200) // 0 == OFF, 1 == ON with slowms, 2 == ON
29
30
db.enableFreeMonitoring()
31
db.disableFreeMonitoring()
32
db.getFreeMonitoringStatus()
33
34
db.createView("viewName", "sourceColl", [{$project:{department: 1}}])

1
watchCursor = db.coll.watch( [ { $match : {"operationType" : "insert" } } ] )
2
3
while (!watchCursor.isExhausted()){
4
   if (watchCursor.hasNext()){
5
      print(tojson(watchCursor.next()));
6
   }
7
}

1
rs.status()
2
rs.initiate({"_id": "RS1",
3
  members: [
4
    { _id: 0, host: "mongodb1.net:27017" },
5
    { _id: 1, host: "mongodb2.net:27017" },
6
    { _id: 2, host: "mongodb3.net:27017" }]
7
})
8
rs.add("mongodb4.net:27017")
9
rs.addArb("mongodb5.net:27017")
10
rs.remove("mongodb1.net:27017")
11
rs.conf()
12
rs.hello()
13
rs.printReplicationInfo()
14
rs.printSecondaryReplicationInfo()
15
rs.reconfig(config)
16
rs.reconfigForPSASet(memberIndex, config, { options } )
17
db.getMongo().setReadPref('secondaryPreferred')
18
rs.stepDown(20, 5) // (stepDownSecs, secondaryCatchUpPeriodSecs)

1
db.printShardingStatus()
2
3
sh.status()
4
sh.addShard("rs1/mongodb1.example.net:27017")
5
sh.shardCollection("mydb.coll", {zipcode: 1})
6
7
sh.moveChunk("mydb.coll", { zipcode: "53187" }, "shard0019")
8
sh.splitAt("mydb.coll", {x: 70})
9
sh.splitFind("mydb.coll", {x: 70})
10
11
sh.startBalancer()
12
sh.stopBalancer()
13
sh.disableBalancing("mydb.coll")
14
sh.enableBalancing("mydb.coll")
15
sh.getBalancerState()
16
sh.setBalancerState(true/false)
17
sh.isBalancerRunning()
18
19
sh.startAutoMerger()
20
sh.stopAutoMerger()
21
sh.enableAutoMerger()
22
sh.disableAutoMerger()
23
24
sh.updateZoneKeyRange("mydb.coll", {state: "NY", zip: MinKey }, { state: "NY", zip: MaxKey }, "NY")
25
sh.removeRangeFromZone("mydb.coll", {state: "NY", zip: MinKey }, { state: "NY", zip: MaxKey })
26
sh.addShardToZone("shard0000", "NYC")
27
sh.removeShardFromZone("shard0000", "NYC")