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mongo Shell Methods

JavaScript in MongoDB

Although these methods use JavaScript, most interactions with MongoDB do not use JavaScript but use an idiomatic driver in the language of the interacting application.

Note

For details on specific methods, including syntax and examples, click on the specific method to go to its reference page.

Collection

Name Description
db.collection.aggregate() Provides access to the aggregation pipeline.
db.collection.bulkWrite() Provides bulk write operation functionality.
db.collection.count() Wraps count to return a count of the number of documents in a collection or matching a query.
db.collection.copyTo() Deprecated. Wraps eval to copy data between collections in a single MongoDB instance.
db.collection.createIndex() Builds an index on a collection.
db.collection.createIndexes() Builds one or more indexes on a collection.
db.collection.dataSize() Returns the size of the collection. Wraps the size field in the output of the collStats.
db.collection.deleteOne() Deletes a single document in a collection.
db.collection.deleteMany() Deletes multiple documents in a collection.
db.collection.distinct() Returns an array of documents that have distinct values for the specified field.
db.collection.drop() Removes the specified collection from the database.
db.collection.dropIndex() Removes a specified index on a collection.
db.collection.dropIndexes() Removes all indexes on a collection.
db.collection.ensureIndex() Deprecated. Use db.collection.createIndex().
db.collection.explain() Returns information on the query execution of various methods.
db.collection.find() Performs a query on a collection and returns a cursor object.
db.collection.findAndModify() Atomically modifies and returns a single document.
db.collection.findOne() Performs a query and returns a single document.
db.collection.findOneAndDelete() Finds a single document and deletes it.
db.collection.findOneAndReplace() Finds a single document and replaces it.
db.collection.findOneAndUpdate() Finds a single document and updates it.
db.collection.getIndexes() Returns an array of documents that describe the existing indexes on a collection.
db.collection.getShardDistribution() For collections in sharded clusters, db.collection.getShardDistribution() reports data of chunk distribution.
db.collection.getShardVersion() Internal diagnostic method for sharded cluster.
db.collection.group() Provides simple data aggregation function. Groups documents in a collection by a key, and processes the results. Use aggregate() for more complex data aggregation.
db.collection.insert() Creates a new document in a collection.
db.collection.insertOne() Inserts a new document in a collection.
db.collection.insertMany() Inserts several new document in a collection.
db.collection.isCapped() Reports if a collection is a capped collection.
db.collection.mapReduce() Performs map-reduce style data aggregation.
db.collection.reIndex() Rebuilds all existing indexes on a collection.
db.collection.replaceOne() Replaces a single document in a collection.
db.collection.remove() Deletes documents from a collection.
db.collection.renameCollection() Changes the name of a collection.
db.collection.save() Provides a wrapper around an insert() and update() to insert new documents.
db.collection.stats() Reports on the state of a collection. Provides a wrapper around the collStats.
db.collection.storageSize() Reports the total size used by the collection in bytes. Provides a wrapper around the storageSize field of the collStats output.
db.collection.totalSize() Reports the total size of a collection, including the size of all documents and all indexes on a collection.
db.collection.totalIndexSize() Reports the total size used by the indexes on a collection. Provides a wrapper around the totalIndexSize field of the collStats output.
db.collection.update() Modifies a document in a collection.
db.collection.updateOne() Modifies a single document in a collection.
db.collection.updateMany() Modifies multiple documents in a collection.
db.collection.validate() Performs diagnostic operations on a collection.

Cursor

Name Description
cursor.addOption() Adds special wire protocol flags that modify the behavior of the query.’
cursor.batchSize() Controls the number of documents MongoDB will return to the client in a single network message.
cursor.close() Close a cursor and free associated server resources.
cursor.comment() Attaches a comment to the query to allow for traceability in the logs and the system.profile collection.
cursor.count() Modifies the cursor to return the number of documents in the result set rather than the documents themselves.
cursor.explain() Reports on the query execution plan for a cursor.
cursor.forEach() Applies a JavaScript function for every document in a cursor.
cursor.hasNext() Returns true if the cursor has documents and can be iterated.
cursor.hint() Forces MongoDB to use a specific index for a query.
cursor.itcount() Computes the total number of documents in the cursor client-side by fetching and iterating the result set.
cursor.limit() Constrains the size of a cursor’s result set.
cursor.map() Applies a function to each document in a cursor and collects the return values in an array.
cursor.maxScan() Specifies the maximum number of items to scan; documents for collection scans, keys for index scans.
cursor.maxTimeMS() Specifies a cumulative time limit in milliseconds for processing operations on a cursor.
cursor.max() Specifies an exclusive upper index bound for a cursor. For use with cursor.hint()
cursor.min() Specifies an inclusive lower index bound for a cursor. For use with cursor.hint()
cursor.next() Returns the next document in a cursor.
cursor.noCursorTimeout() Instructs the server to avoid closing a cursor automatically after a period of inactivity.
cursor.objsLeftInBatch() Returns the number of documents left in the current cursor batch.
cursor.pretty() Configures the cursor to display results in an easy-to-read format.
cursor.readConcern() Specifies a read concern for a find() operation.
cursor.readPref() Specifies a read preference to a cursor to control how the client directs queries to a replica set.
cursor.returnKey() Modifies the cursor to return index keys rather than the documents.
cursor.showRecordId() Adds an internal storage engine ID field to each document returned by the cursor.
cursor.size() Returns a count of the documents in the cursor after applying skip() and limit() methods.
cursor.skip() Returns a cursor that begins returning results only after passing or skipping a number of documents.
cursor.snapshot() Forces the cursor to use the index on the _id field. Ensures that the cursor returns each document, with regards to the value of the _id field, only once.
cursor.sort() Returns results ordered according to a sort specification.
cursor.tailable() Marks the cursor as tailable. Only valid for cursors over capped collections.
cursor.toArray() Returns an array that contains all documents returned by the cursor.

Database

Name Description
db.cloneCollection() Copies data directly between MongoDB instances. Wraps cloneCollection.
db.cloneDatabase() Copies a database from a remote host to the current host. Wraps clone.
db.commandHelp() Returns help information for a database command.
db.copyDatabase() Copies a database to another database on the current host. Wraps copydb.
db.createCollection() Creates a new collection. Commonly used to create a capped collection.
db.currentOp() Reports the current in-progress operations.
db.dropDatabase() Removes the current database.
db.eval() Deprecated. Passes a JavaScript function to the mongod instance for server-side JavaScript evaluation.
db.fsyncLock() Flushes writes to disk and locks the database to prevent write operations and assist backup operations. Wraps fsync.
db.fsyncUnlock() Allows writes to continue on a database locked with db.fsyncLock().
db.getCollection() Returns a collection object. Used to access collections with names that are not valid in the mongo shell.
db.getCollectionInfos() Returns collection information for all collections in the current database.
db.getCollectionNames() Lists all collections in the current database.
db.getLastError() Checks and returns the status of the last operation. Wraps getLastError.
db.getLastErrorObj() Returns the status document for the last operation. Wraps getLastError.
db.getLogComponents() Returns the log message verbosity levels.
db.getMongo() Returns the Mongo() connection object for the current connection.
db.getName() Returns the name of the current database.
db.getPrevError() Returns a status document containing all errors since the last error reset. Wraps getPrevError.
db.getProfilingLevel() Returns the current profiling level for database operations.
db.getProfilingStatus() Returns a document that reflects the current profiling level and the profiling threshold.
db.getReplicationInfo() Returns a document with replication statistics.
db.getSiblingDB() Provides access to the specified database.
db.help() Displays descriptions of common db object methods.
db.hostInfo() Returns a document with information about the system MongoDB runs on. Wraps hostInfo
db.isMaster() Returns a document that reports the state of the replica set.
db.killOp() Terminates a specified operation.
db.listCommands() Displays a list of common database commands.
db.loadServerScripts() Loads all scripts in the system.js collection for the current database into the shell session.
db.logout() Ends an authenticated session.
db.printCollectionStats() Prints statistics from every collection. Wraps db.collection.stats().
db.printReplicationInfo() Prints a report of the status of the replica set from the perspective of the primary.
db.printShardingStatus() Prints a report of the sharding configuration and the chunk ranges.
db.printSlaveReplicationInfo() Prints a report of the status of the replica set from the perspective of the secondaries.
db.repairDatabase() Runs a repair routine on the current database.
db.resetError() Resets the error message returned by db.getPrevError() and getPrevError.
db.runCommand() Runs a database command.
db.serverBuildInfo() Returns a document that displays the compilation parameters for the mongod instance. Wraps buildinfo.
db.serverCmdLineOpts() Returns a document with information about the runtime used to start the MongoDB instance. Wraps getCmdLineOpts.
db.serverStatus() Returns a document that provides an overview of the state of the database process.
db.setLogLevel() Sets a single log message verbosity level.
db.setProfilingLevel() Modifies the current level of database profiling.
db.shutdownServer() Shuts down the current mongod or mongos process cleanly and safely.
db.stats() Returns a document that reports on the state of the current database.
db.version() Returns the version of the mongod instance.
db.upgradeCheck() Performs a preliminary check for upgrade preparedness for a specific database or collection.
db.upgradeCheckAllDBs() Performs a preliminary check for upgrade preparedness for all databases and collections.

Query Plan Cache

Name Description
db.collection.getPlanCache() Returns an interface to access the query plan cache object and associated PlanCache methods for a collection.”
PlanCache.help() Displays the methods available for a collection’s query plan cache. Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().help().
PlanCache.listQueryShapes() Displays the query shapes for which cached query plans exist. Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().listQueryShapes().
PlanCache.getPlansByQuery() Displays the cached query plans for the specified query shape. Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().getPlansByQuery().
PlanCache.clearPlansByQuery() Clears the cached query plans for the specified query shape. Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().clearPlansByQuery()
PlanCache.clear() Clears all the cached query plans for a collection. Accessible through the plan cache object of a specific collection, i.e. db.collection.getPlanCache().clear().

Bulk Write Operation

Name Description
Bulk() Bulk operations builder.
db.collection.initializeOrderedBulkOp() Initializes a Bulk() operations builder for an ordered list of operations.
db.collection.initializeUnorderedBulkOp() Initializes a Bulk() operations builder for an unordered list of operations.
Bulk.insert() Adds an insert operation to a list of operations.
Bulk.find() Specifies the query condition for an update or a remove operation.
Bulk.find.removeOne() Adds a single document remove operation to a list of operations.
Bulk.find.remove() Adds a multiple document remove operation to a list of operations.
Bulk.find.replaceOne() Adds a single document replacement operation to a list of operations.
Bulk.find.updateOne() Adds a single document update operation to a list of operations.
Bulk.find.update() Adds a multi update operation to a list of operations.
Bulk.find.upsert() Specifies upsert: true for an update operation.
Bulk.execute() Executes a list of operations in bulk.
Bulk.getOperations() Returns an array of write operations executed in the Bulk() operations object.
Bulk.tojson() Returns a JSON document that contains the number of operations and batches in the Bulk() operations object.
Bulk.toString() Returns the Bulk.tojson() results as a string.

User Management

Name Description
db.auth() Authenticates a user to a database.
db.createUser() Creates a new user.
db.updateUser() Updates user data.
db.changeUserPassword() Changes an existing user’s password.
db.removeUser() Deprecated. Removes a user from a database.
db.dropAllUsers() Deletes all users associated with a database.
db.dropUser() Removes a single user.
db.grantRolesToUser() Grants a role and its privileges to a user.
db.revokeRolesFromUser() Removes a role from a user.
db.getUser() Returns information about the specified user.
db.getUsers() Returns information about all users associated with a database.

Role Management

Name Description
db.createRole() Creates a role and specifies its privileges.
db.updateRole() Updates a user-defined role.
db.dropRole() Deletes a user-defined role.
db.dropAllRoles() Deletes all user-defined roles associated with a database.
db.grantPrivilegesToRole() Assigns privileges to a user-defined role.
db.revokePrivilegesFromRole() Removes the specified privileges from a user-defined role.
db.grantRolesToRole() Specifies roles from which a user-defined role inherits privileges.
db.revokeRolesFromRole() Removes inherited roles from a role.
db.getRole() Returns information for the specified role.
db.getRoles() Returns information for all the user-defined roles in a database.

Replication

Name Description
rs.add() Adds a member to a replica set.
rs.addArb() Adds an arbiter to a replica set.
rs.conf() Returns the replica set configuration document.
rs.freeze() Prevents the current member from seeking election as primary for a period of time.
rs.help() Returns basic help text for replica set functions.
rs.initiate() Initializes a new replica set.
rs.printReplicationInfo() Prints a report of the status of the replica set from the perspective of the primary.
rs.printSlaveReplicationInfo() Prints a report of the status of the replica set from the perspective of the secondaries.
rs.reconfig() Re-configures a replica set by applying a new replica set configuration object.
rs.remove() Remove a member from a replica set.
rs.status() Returns a document with information about the state of the replica set.
rs.stepDown() Causes the current primary to become a secondary which forces an election.
rs.syncFrom() Sets the member that this replica set member will sync from, overriding the default sync target selection logic.

Sharding

Name Description
sh.getBalancerLockDetails() Reports on the active balancer lock, if it exists.
sh.addShard() Adds a shard to a sharded cluster.
sh.addShardTag() Associates a shard with a tag, to support tag aware sharding.
sh.addTagRange() Associates range of shard keys with a shard tag, to support tag aware sharding.
sh.removeTagRange() Removes an association between a range shard keys and a shard tag. Use to manage tag aware sharding.
sh.disableBalancing() Disable balancing on a single collection in a sharded database. Does not affect balancing of other collections in a sharded cluster.
sh.enableBalancing() Activates the sharded collection balancer process if previously disabled using sh.disableBalancing().
sh.enableSharding() Enables sharding on a specific database.
sh.getBalancerHost() Returns the name of a mongos that’s responsible for the balancer process.
sh.getBalancerState() Returns a boolean to report if the balancer is currently enabled.
sh.help() Returns help text for the sh methods.
sh.isBalancerRunning() Returns a boolean to report if the balancer process is currently migrating chunks.
sh.moveChunk() Migrates a chunk in a sharded cluster.
sh.removeShardTag() Removes the association between a shard and a shard tag.
sh.setBalancerState() Enables or disables the balancer which migrates chunks between shards.
sh.shardCollection() Enables sharding for a collection.
sh.splitAt() Divides an existing chunk into two chunks using a specific value of the shard key as the dividing point.
sh.splitFind() Divides an existing chunk that contains a document matching a query into two approximately equal chunks.
sh.startBalancer() Enables the balancer and waits for balancing to start.
sh.status() Reports on the status of a sharded cluster, as db.printShardingStatus().
sh.stopBalancer() Disables the balancer and waits for any in progress balancing rounds to complete.
sh.waitForBalancer() Internal. Waits for the balancer state to change.
sh.waitForBalancerOff() Internal. Waits until the balancer stops running.
sh.waitForPingChange() Internal. Waits for a change in ping state from one of the mongos in the sharded cluster.

Constructors

Name Description
Date() Creates a date object. By default creates a date object including the current date.
UUID() Converts a 32-byte hexadecimal string to the UUID BSON subtype.
ObjectId() Returns an ObjectId.
ObjectId.getTimestamp() Returns the timestamp portion of an ObjectId.
ObjectId.toString() Displays the string representation of an ObjectId.
ObjectId.valueOf() Displays the str attribute of an ObjectId as a hexadecimal string.
WriteResult() Wrapper around the result set from write methods.
WriteResult.hasWriteError() Returns a boolean specifying whether the results include WriteResult.writeError.
WriteResult.hasWriteConcernError() Returns a boolean specifying whether whether the results include WriteResult.writeConcernError.
BulkWriteResult() Wrapper around the result set from Bulk.execute().

Connection

Name Description
Mongo.getDB() Returns a database object.
Mongo.getReadPrefMode() Returns the current read preference mode for the MongoDB connection.
Mongo.getReadPrefTagSet() Returns the read preference tag set for the MongoDB connection.
Mongo.setReadPref() Sets the read preference for the MongoDB connection.
Mongo() Creates a new connection object.
connect() Connects to a MongoDB instance and to a specified database on that instance.

Native

Name Description
cat() Returns the contents of the specified file.
version() Returns the current version of the mongo shell instance.
cd() Changes the current working directory to the specified path.
sleep() Suspends the mongo shell for a given period of time.
copyDbpath() Copies a local dbPath. For internal use.
resetDbpath() Removes a local dbPath. For internal use.
getHostName() Returns the hostname of the system running the mongo shell.
getMemInfo() Returns a document that reports the amount of memory used by the shell.
hostname() Returns the hostname of the system running the shell.
_isWindows() Returns true if the shell runs on a Windows system; false if a Unix or Linux system.
listFiles() Returns an array of documents that give the name and size of each object in the directory.
load() Loads and runs a JavaScript file in the shell.
ls() Returns a list of the files in the current directory.
md5sumFile() The md5 hash of the specified file.
mkdir() Creates a directory at the specified path.
pwd() Returns the current directory.
quit() Exits the current shell session.
_rand() Returns a random number between 0 and 1.
removeFile() Removes the specified file from the local file system.
setVerboseShell() Configures the mongo shell to report operation timing.