Mongo – cli quick start guide

Using mongo cli utility can be handy way to query mongo db and automate few simple use cases. This article covers some handy commands which can be used with mongo cli utility. This article assumes that you have mongo server installed on local machine. I tested these commands on Mac. But these should work on any other OS.

Install mongo server

Use the following command on Mac:

$ brew install mongo
// To run mongodb one time
$ launchctl load /usr/local/opt/mongodb/homebrew.mxcl.mongodb.plist
// To run on startup
ln -sfv /usr/local/opt/mongodb/*.plist ~/Library/LaunchAgents

Create collection

Create collection in new or existing db:

$ printf "db.createCollection('testcollection1')" | mongo --quiet testdb1
{ "ok" : 1 }
$ printf "db.getCollectionNames()" | mongo --quiet testdb1
[ "system.indexes", "testcollection1" ]
//or
$ printf "show collections"  | mongo --quiet testdb1
system.indexes
testcollection1

drop collection or delete documents in a collection

To drop a collection:

$ printf 'db.testcollection1.drop()' | mongo --quiet testdb1
true

To delete documents in a collection:

$ printf "db.testcollection1.remove({})" | mongo --quiet testdb1
WriteResult({ "nRemoved" : 0 })

List dbs and collections

List dbs and collections in mongo

$ printf "show dbs" | mongo --quiet
local    0.078GB
testdb1  0.078GB
$ printf "show collections"  | mongo --quiet testdb1
system.indexes
testcollection1

insert documents

Insert few test documents in collection

$ printf 'db.testcollection1.insert({key1:"value1"})' | mongo --quiet testdb1
WriteResult({ "nInserted" : 1 })
$ printf 'db.testcollection1.insert({})' | mongo --quiet testdb1
$ printf 'db.testcollection1.insert({})' | mongo --quiet testdb1
// With each document insert an the _id field is automatically created.

Query documents from a collection

Query all documents with limit 1000

$ printf 'db.testcollection1.find({}).limit(1000)' | mongo --quiet testdb1
{ "_id" : ObjectId("55bf6d34e72610341df44d43"), "key1" : "value1" }
{ "_id" : ObjectId("55bf6d8f8d923f4cfbb3294f") }
{ "_id" : ObjectId("55bf6d926a78c27ae1e81d7a") }

You can skip limit(1000) to return all documents.
Query all values where key1 is not equal to “value1”

$ printf 'db.testcollection1.find({key1:{$ne:"value1"}})' | mongo --quiet testdb1