Mongodb

Quick commands

Show all databases

show dbs

Create a database

use <db name>

Add a collection

db.createCollection("<collection name>")

Show all collections in a database

show collections
show tables
db.getCollectionNames()

Show all users in a database

show users

Enable authenticaication and authorization

• Create the user administrator (ex. userAdmin)

  use admin
  db.createUser(
  {
   user: "userAdmin",
   pwd: "Your secret password",
   roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]
  })
  

• Create user for a database (ex. marketing)

  use marketing
  db.createUser(
  {
   user: "marketingUser",
   pwd: "the secret",
   roles: [ { role: "readWrite", db: "marketing" } ]
  })
  

• Restart MonogoDB instance with access control

  mongod --auth
  

• Update docker-compose file to enable Mondodb auth in docker

  mongodb:
  image: mongo:3
  container_name: mongodb-marketing
  restart: always
  command: mongod --auth
  

• Connect and authorization as the user administrator

  mongo --port 27017 -u "userAdmin" -p "your secret" --authenticationDatabase "admin"
  #: next command will ask for user password from console
  mongo --port 27017 -u "userAdmin" --authenticationDatabase "admin"
  

• Connect and authorization as the database user

  mongo --port 27017 -u "marketingUser" -p "your secret" --authenticationDatabase "marketing"
  #: next command will ask for user password from console
  mongo --port 27017 -u "marketingUser" --authenticationDatabase "marketing"
  

User Management

• View a User’s Role

  use reporting
  db.getUser("reportsUser")
  

• View a Roles Privileges

  use products
  db.getRole( "read", { showPrivileges: true } )
  

• Grant a role

  use reporting
  db.grantRolesToUser(
    "reportsUser",
    [
      { role: "read", db: "accounts" }
    ]
  )
  

• Revoke a role

  use reporting
  db.revokeRolesFromUser(
    "reportsUser",
    [
      { role: "readWrite", db: "accounts" }
    ]
  )
  

• Modify the Password for an Existing User

  db.changeUserPassword("reporting", "SOh3TbYhxuLiW8ypJPxmt1oOfL")
  

• Change own password and custome data
  • Create a role

    use admin
    db.createRole(
     { role: "changeOwnPasswordCustomDataRole",
       privileges: [
      {
        resource: { db: "", collection: ""},
        actions: [ "changeOwnPassword", "changeOwnCustomData" ]
      }
       ],
       roles: []
     }
    )
    

  • Add a user with this role

    use test
    db.createUser(
     {
       user:"user123",
       pwd:"12345678",
       roles:[ "readWrite", { role:"changeOwnPasswordCustomDataRole", db:"admin" } ]
     }
    )
    

  • Change you own password and custom data

    mongo --port 27017 -u user123 -p '12345678' --authenticationDatabase 'test'
    use test
    db.updateUser(
     "user123",
     {
    pwd: "KNlZmiaNUp0B",
    customData: { title: "Senior Manager" }
     }
    )
    

buildin Roles

• Database User Roles: read, readWrite
• Database Adminitration Roles: dbAdmin, dbOwner, userAdmin
• Roles in admin Database
  • Cluster Administration Roles: clusterAdmin, ClusterManager, clusterMonitor, hostManger
  • Backup and Restoration Roles: backup, restore
  • All Database Roles: readAnyDatabase, readWriteAnyDatabase, userAdminAnyDatabase, dbAdminAnyDatabase
  • Superuser Roles: root

For roles detail: https://docs.mongodb.com/manual/core/security-built-in-roles/

Backup and Restore

• Backup database (database name is reporting)

  mongodump -u backupUser -p <your secret> --authenticationDatabase admin --gzip --db reporting --archive=<filename>
  

• Restore database

mongorestore --gzip --archive=/tmp/reporting.mongo.2017-08-31.archive -u restoreUser -p <your secret>

mongorestore --drop --gzip --archive=/tmp/reporting.mongo.2017-08-31.archive -u restoreUser -p <your secret>

mongorestore --drop --gzip --db reporting --collection <collection name> --archive=/tmp/reporting.mongo.2017-08-31.archive -u restoreUser -p <your secret>

Example commands

Dataabase

use test # create test database if not exists
db.dropDatabase()
show dbs

Collection

db.createCollection("mycol", { capped : true, autoIndexId : true, size :
   6142800, max : 10000 } )
show collections
db.mycol.drop()

Insert document

db.mycol.insert({
   _id: ObjectId(7df78ad8902c),
   title: 'MongoDB Overview',
   description: 'MongoDB is no sql database',
   by: 'tutorials point',
   url: 'http://www.tutorialspoint.com',
   tags: ['mongodb', 'database', 'NoSQL'],
   likes: 100
})

Insert multiple documents

db.post.insert([
   {
      title: 'MongoDB Overview',
      description: 'MongoDB is no sql database',
      by: 'tutorials point',
      url: 'http://www.tutorialspoint.com',
      tags: ['mongodb', 'database', 'NoSQL'],
      likes: 100
   },

   {
      title: 'NoSQL Database',
      description: "NoSQL database doesn't have tables",
      by: 'tutorials point',
      url: 'http://www.tutorialspoint.com',
      tags: ['mongodb', 'database', 'NoSQL'],
      likes: 20,
      comments: [
         {
            user:'user1',
            message: 'My first comment',
            dateCreated: new Date(2013,11,10,2,35),
            like: 0
         }
      ]
   }
])

Query document

db.mycol.find().pretty()

db.mycol.find({"by":"tutorials point"}).pretty()
db.mycol.find({"likes":{$lt:50}}).pretty()
db.mycol.find({"likes":{$lte:50}}).pretty()
db.mycol.find({"likes":{$gt:50}}).pretty()
db.mycol.find({"likes":{$gte:50}}).pretty()
db.mycol.find({"likes":{$ne:50}}).pretty()

db.mycol.find(
   {
      $and: [
         {key1: value1}, {key2:value2}
      ]
   }
).pretty()

db.mycol.find(
   {
      $or: [
         {key1: value1}, {key2:value2}
      ]
   }
).pretty()

Update docment

db.COLLECTION_NAME.update(SELECTION_CRITERIA, UPDATED_DATA)

db.mycol.update({'title':'MongoDB Overview'},{$set:{'title':'New MongoDB Tutorial'}})

By default, MongoDB will update only a single document. To update multiple documents, you need to set a parameter ‘multi’ to true.

db.mycol.update({'title':'MongoDB Overview'},
   {$set:{'title':'New MongoDB Tutorial'}},{multi:true})

Replace a existing document

The save() method replaces the existing document with the new document passed in the save() method.

db.mycol.save(
   {
      "_id" : ObjectId(5983548781331adf45ec7), "title":"Tutorials Point New Topic",
         "by":"Tutorials Point"
   }
)

Remove document

db.mycol.remove({'title':'MongoDB Overview'})
db.mycol.remove({'title':'MongoDB Overview'}, 1) # remove only one
db.mycol.remove({}) # remove all

Projection

db.mycol.find({},{"title":1,_id:0}) # 1 - show, 0 - hide

Limiting records

db.mycol.find({},{"title":1,_id:0}).limit(2)
db.mycol.find({},{"title":1,_id:0}).limit(1).skip(1) # only display the 2nd document

Sorting records

db.mycol.find({},{"title":1,_id:0}).sort({"title":-1})

Indexing

db.mycol.ensureIndex({"title":1,"description":-1})

Aggregation

db.mycol.aggregate([{$group : {_id : "$by_user", num_tutorial : {$sum : 1}}}])
{
   "result" : [
      {
         "_id" : "tutorials point",
         "num_tutorial" : 2
      },
      {
         "_id" : "Neo4j",
         "num_tutorial" : 1
      }
   ],
   "ok" : 1
}

db.mycol.aggregate([{$group : {_id : "$by_user", num_tutorial : {$sum : "$likes"}}}])
db.mycol.aggregate([{$group : {_id : "$by_user", num_tutorial : {$avg : "$likes"}}}])
db.mycol.aggregate([{$group : {_id : "$by_user", num_tutorial : {$min : "$likes"}}}])
db.mycol.aggregate([{$group : {_id : "$by_user", num_tutorial : {$max : "$likes"}}}])
db.mycol.aggregate([{$group : {_id : "$by_user", url : {$push: "$url"}}}])
db.mycol.aggregate([{$group : {_id : "$by_user", url : {$addToSet : "$url"}}}])
db.mycol.aggregate([{$group : {_id : "$by_user", first_url : {$first : "$url"}}}])
db.mycol.aggregate([{$group : {_id : "$by_user", last_url : {$last : "$url"}}}])

Enable rest api

Add a line in /etc/mongodb.conf

rest = true