MongoDB Commands

Commands

• mongod - start mongo db server instance
• mongo - start mongo db command prompt to execute commands
• show dbs - show databases
• mongoimport -d [DATABASE_NAME] -c [COLLECTIONS] --file [FILE_NAME] - import into database and collection from file
• mongoexport -d [DATABASE_NEM] -c [COLLECTIONS] --out [FILE_NAME] - export db in json
• mongodump - binary export
• mongorestore - restore binary export
• bsondump
• mongostat
• use [DB_NAME]- change/switch DB. There is NO command to create DB
• db - set variable as DB (after user [DB_NAME])
• db.[COLLECTIONS] - e.g. db.links. Don't have to create collections (similar to DB)
• db.[COLLECTIONS].count() - to check number of documents. e.g. db.links.count()
• db.[COLLECTIONS].insert({[JSON_DATA]}) - e.g. db.links.insert({title: "google search", url:"www.google.com", comment:"top search engine", tags:["default","main page"], saved_on: new Date()})
• db.[COLLECTIONS].save({[JSON_DATA]}) - e.g. db.links.save({title: "yahoo search", url: "www.yahoo.com", saved_on: new Date()})
• db.[COLLECTIONS].find() - e.g. db.links.find(). Query the database to find the documents

Examples

• show collections - show collections for db
• db.users.insert({"name":"username"}) - insert collection user with data
• db.users.count() - show count of collections
• db.users.find() - find all data from collection
• db.users.find().explain() - explain execution planner for query to find data
• db.users.find().explain("executionStats") - more information on explain
• db.users.createIndex({number:1}) - to create an index on collection
• db.users.update({"name":"username"}, $set: {"first_name":"Name"})" - $set update record
• db.users.update({"name":"username"}, {$addToSet: {"hobbies":"running"}})" - $addToSet update array with new value
• db.users.remove({"name":"username"}) - remove record
• db.users.drop() - drop entire users collection

Notes

• bson: binary JSON
• Collection: Like an RDBMS table; but collection has no schemas.
• Document: Like an RDBMS record or row. There are bson documents.
• Field: Like an RDBMS column; {key: value}