Class: Collection

Methods

aggregate(pipeline, options, callback){null|AggregationCursor}

lib/collection.js, line 1705

Execute an aggregation framework pipeline against the collection, needs MongoDB >= 2.2

Name	Type	Default	Description
pipeline	object	[]	optional Array containing all the aggregation framework commands for the execution.
options	object		optional Optional settings. Name Type Default Description readPreference ReadPreference | string optional The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST). cursor object optional Return the query as cursor, on 2.6 > it returns as a real cursor on pre 2.6 it returns as an emulated cursor. Name Type Description batchSize number optional The batchSize for the cursor explain boolean false optional Explain returns the aggregation execution plan (requires mongodb 2.6 >). allowDiskUse boolean false optional allowDiskUse lets the server know if it can use disk to store temporary results for the aggregation (requires mongodb 2.6 >). maxTimeMS number optional maxTimeMS specifies a cumulative time limit in milliseconds for processing operations on the cursor. MongoDB interrupts the operation at the earliest following interrupt point. bypassDocumentValidation boolean false optional Allow driver to bypass schema validation in MongoDB 3.2 or higher. raw boolean false optional Return document results as raw BSON buffers. promoteLongs boolean true optional Promotes Long values to number if they fit inside the 53 bits resolution. promoteValues boolean true optional Promotes BSON values to native types where possible, set to false to only receive wrapper types. promoteBuffers boolean false optional Promotes Binary BSON values to native Node Buffers. collation object optional Specify collation (MongoDB 3.4 or higher) settings for update operation (see 3.4 documentation for available fields). comment string optional Add a comment to an aggregation command hint string | object optional Add an index selection hint to an aggregation command session ClientSession optional optional session to use for this operation
callback	Collection~aggregationCallback		The command result callback

bulkWrite(operations, options, callback){Promise}

lib/collection.js, line 587

Perform a bulkWrite operation without a fluent API

Legal operation types are

{ insertOne: { document: { a: 1 } } }

{ updateOne: { filter: {a:2}, update: {$set: {a:2}}, upsert:true } }

{ updateMany: { filter: {a:2}, update: {$set: {a:2}}, upsert:true } }

{ deleteOne: { filter: {c:1} } }

{ deleteMany: { filter: {c:1} } }

{ replaceOne: { filter: {c:3}, replacement: {c:4}, upsert:true}}

If documents passed in do not contain the _id field,
one will be added to each of the documents missing it by the driver, mutating the document. This behavior
can be overridden by setting the forceServerObjectId flag.

Name	Type	Description
operations	Array.<object>	Bulk operations to perform.
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. serializeFunctions boolean false optional Serialize functions on any object. ordered boolean true optional Execute write operation in ordered or unordered fashion. bypassDocumentValidation boolean false optional Allow driver to bypass schema validation in MongoDB 3.2 or higher. session ClientSession optional optional session to use for this operation
callback	Collection~bulkWriteOpCallback	optional The command result callback

Returns:

Promise if no callback passed

count(query, options, callback){Promise}

lib/collection.js, line 1374

An estimated count of matching documents in the db to a query.

NOTE: This method has been deprecated, since it does not provide an accurate count of the documents
in a collection. To obtain an accurate count of documents in the collection, use countDocuments.
To obtain an estimated count of all documents in the collection, use estimatedDocumentCount.

Name	Type	Default	Description
query	object	{}	optional The query for the count.
options	object		optional Optional settings. Name Type Description limit boolean optional The limit of documents to count. skip boolean optional The number of documents to skip for the count. hint string optional An index name hint for the query. readPreference ReadPreference | string optional The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST). maxTimeMS number optional Number of miliseconds to wait before aborting the query. session ClientSession optional optional session to use for this operation
callback	Collection~countCallback		optional The command result callback

Deprecated

• use countDocuments or estimatedDocumentCount instead

Returns:

Promise if no callback passed

countDocuments(query, options, callback){Promise}

lib/collection.js, line 1432

Gets the number of documents matching the filter.

Note: When migrating from count to countDocuments
the following query operators must be replaced:

Operator	Replacement
$where	$expr
$near	$geoWithin with $center
$nearSphere	$geoWithin with $centerSphere

Name	Type	Description
query	object	optional the query for the count
options	object	optional Optional settings. Name Type Description collation object optional Specifies a collation. hint string | object optional The index to use. limit number optional The maximum number of document to count. maxTimeMS number optional The maximum amount of time to allow the operation to run. skip number optional The number of documents to skip before counting.
callback	Collection~countCallback	optional The command result callback.

See:

• https://www.mongodb.com/docs/manual/reference/operator/query/expr/
• https://www.mongodb.com/docs/manual/reference/operator/query/geoWithin/
• https://www.mongodb.com/docs/manual/reference/operator/query/center/#op._S_center
• https://www.mongodb.com/docs/manual/reference/operator/query/centerSphere/#op._S_centerSphere

Returns:

Promise if no callback passed.

createIndex(fieldOrSpec, options, callback){Promise}

lib/collection.js, line 1135

Creates an index on the db and collection collection.

Name	Type	Description
fieldOrSpec	string | object	Defines the index.
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. unique boolean false optional Creates an unique index. sparse boolean false optional Creates a sparse index. background boolean false optional Creates the index in the background, yielding whenever possible. dropDups boolean false optional A unique index cannot be created on a key that has pre-existing duplicate values. If you would like to create the index anyway, keeping the first document the database indexes and deleting all subsequent documents that have duplicate value min number optional For geospatial indexes set the lower bound for the co-ordinates. max number optional For geospatial indexes set the high bound for the co-ordinates. v number optional Specify the format version of the indexes. expireAfterSeconds number optional Allows you to expire data on indexes applied to a data (MongoDB 2.2 or higher) name string optional Override the autogenerated index name (useful if the resulting name is larger than 128 bytes) partialFilterExpression object optional Creates a partial index based on the given filter object (MongoDB 3.2 or higher) collation object optional Specify collation (MongoDB 3.4 or higher) settings for update operation (see 3.4 documentation for available fields). session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Returns:

Promise if no callback passed

createIndexes(indexSpecs, options, callback){Promise}

lib/collection.js, line 1153

Creates multiple indexes in the collection, this method is only supported for
MongoDB 2.6 or higher. Earlier version of MongoDB will throw a command not supported
error. Index specifications are defined at https://www.mongodb.com/docs/manual/reference/command/createIndexes/.

Name	Type	Description
indexSpecs	array	An array of index specifications to be created
options	Object	optional Optional settings Name Type Description session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Returns:

Promise if no callback passed

deleteMany(filter, options, callback){Promise}

lib/collection.js, line 897

Delete multiple documents from a collection

Name	Type	Description
filter	object	The Filter used to select the documents to remove
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. session ClientSession optional optional session to use for this operation
callback	Collection~deleteWriteOpCallback	optional The command result callback

Returns:

Promise if no callback passed

deleteOne(filter, options, callback){Promise}

lib/collection.js, line 870

Delete a document from a collection

Name	Type	Description
filter	object	The Filter used to select the document to remove
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. session ClientSession optional optional session to use for this operation
callback	Collection~deleteWriteOpCallback	optional The command result callback

Returns:

Promise if no callback passed

distinct(key, query, options, callback){Promise}

lib/collection.js, line 1453

The distinct command returns returns a list of distinct values for the given key across a collection.

Name	Type	Description
key	string	Field of the document to find distinct values for.
query	object	The query for filtering the set of documents to which we apply the distinct filter.
options	object	optional Optional settings. Name Type Description readPreference ReadPreference | string optional The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST). maxTimeMS number optional Number of miliseconds to wait before aborting the query. session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Returns:

Promise if no callback passed

drop(options, callback){Promise}

lib/collection.js, line 1069

Drop the collection from the database, removing it permanently. New accesses will create a new collection.

Name	Type	Description
options	object	optional Optional settings. Name Type Description session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The results callback

Returns:

Promise if no callback passed

dropAllIndexes(callback){Promise}

lib/collection.js, line 1211

Drops all indexes from this collection.

Name	Type	Description
callback	Collection~resultCallback	The command result callback

Deprecated

• use dropIndexes

Returns:

Promise if no [callback] passed

dropIndex(indexName, options, callback){Promise}

lib/collection.js, line 1175

Drops an index from this collection.

Name	Type	Description
indexName	string	Name of the index to drop.
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. session ClientSession optional optional session to use for this operation maxTimeMS number optional Number of miliseconds to wait before aborting the query.
callback	Collection~resultCallback	optional The command result callback

Returns:

Promise if no callback passed

dropIndexes(options, callback){Promise}

lib/collection.js, line 1195

Drops all indexes from this collection.

Name	Type	Description
options	Object	optional Optional settings Name Type Description session ClientSession optional optional session to use for this operation maxTimeMS number optional Number of miliseconds to wait before aborting the query.
callback	Collection~resultCallback	optional The command result callback

Returns:

Promise if no callback passed

ensureIndex(fieldOrSpec, options, callback){Promise}

lib/collection.js, line 1307

Ensures that an index exists, if it does not it creates it

Name	Type	Description
fieldOrSpec	string | object	Defines the index.
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. unique boolean false optional Creates an unique index. sparse boolean false optional Creates a sparse index. background boolean false optional Creates the index in the background, yielding whenever possible. dropDups boolean false optional A unique index cannot be created on a key that has pre-existing duplicate values. If you would like to create the index anyway, keeping the first document the database indexes and deleting all subsequent documents that have duplicate value min number optional For geospatial indexes set the lower bound for the co-ordinates. max number optional For geospatial indexes set the high bound for the co-ordinates. v number optional Specify the format version of the indexes. expireAfterSeconds number optional Allows you to expire data on indexes applied to a data (MongoDB 2.2 or higher) name number optional Override the autogenerated index name (useful if the resulting name is larger than 128 bytes) collation object optional Specify collation (MongoDB 3.4 or higher) settings for update operation (see 3.4 documentation for available fields). session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Deprecated

• use createIndexes instead

Returns:

Promise if no callback passed

estimatedDocumentCount(options, callback){Promise}

lib/collection.js, line 1393

Gets an estimate of the count of documents in a collection using collection metadata.

Name	Type	Description
options	object	optional Optional settings. Name Type Description maxTimeMS number optional The maximum amount of time to allow the operation to run.
callback	Collection~countCallback	optional The command result callback.

Returns:

Promise if no callback passed.

find(query, options){Cursor}

lib/collection.js, line 278

Creates a cursor for a query that can be used to iterate over results from MongoDB

Name	Type	Default	Description
query	object	{}	optional The cursor query object.
options	object		optional Optional settings. Name Type Default Description limit number 0 optional Sets the limit of documents returned in the query. sort array | object optional Set to sort the documents coming back from the query. Array of indexes, [['a', 1]] etc. projection object optional The fields to return in the query. Object of fields to include or exclude (not both), {'a':1} fields object optional Deprecated Use options.projection instead skip number 0 optional Set to skip N documents ahead in your query (useful for pagination). hint Object optional Tell the query to use specific indexes in the query. Object of indexes to use, {'_id':1} explain boolean false optional Explain the query instead of returning the data. snapshot boolean false optional DEPRECATED: Snapshot query. timeout boolean false optional Specify if the cursor can timeout. tailable boolean false optional Specify if the cursor is tailable. batchSize number 0 optional Set the batchSize for the getMoreCommand when iterating over the query results. returnKey boolean false optional Only return the index key. maxScan number optional DEPRECATED: Limit the number of items to scan. min number optional Set index bounds. max number optional Set index bounds. showDiskLoc boolean false optional Show disk location of results. comment string optional You can put a $comment field on a query to make looking in the profiler logs simpler. raw boolean false optional Return document results as raw BSON buffers. promoteLongs boolean true optional Promotes Long values to number if they fit inside the 53 bits resolution. promoteValues boolean true optional Promotes BSON values to native types where possible, set to false to only receive wrapper types. promoteBuffers boolean false optional Promotes Binary BSON values to native Node Buffers. readPreference ReadPreference | string optional The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST). partial boolean false optional Specify if the cursor should return partial results when querying against a sharded system maxTimeMS number optional Number of miliseconds to wait before aborting the query. collation object optional Specify collation (MongoDB 3.4 or higher) settings for update operation (see 3.4 documentation for available fields). session ClientSession optional optional session to use for this operation

Throws:

MongoError

findAndModify(query, sort, doc, options, callback){Promise}

lib/collection.js, line 1637

Find and update a document.

Name	Type	Description
query	object	Query object to locate the object to modify.
sort	array	If multiple docs match, choose the first one in the specified sort order as the object to manipulate.
doc	object	The fields/vals to be updated.
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. remove boolean false optional Set to true to remove the object before returning. upsert boolean false optional Perform an upsert operation. new boolean false optional Set to true if you want to return the modified object rather than the original. Ignored for remove. projection object optional Object containing the field projection for the result returned from the operation. fields object optional Deprecated Use options.projection instead session ClientSession optional optional session to use for this operation arrayFilters Array optional optional list of array filters referenced in filtered positional operators
callback	Collection~findAndModifyCallback	optional The command result callback

Deprecated

• use findOneAndUpdate, findOneAndReplace or findOneAndDelete instead

Returns:

Promise if no callback passed

findAndRemove(query, sort, options, callback){Promise}

lib/collection.js, line 1673

Find and remove a document.

Name	Type	Description
query	object	Query object to locate the object to modify.
sort	array	If multiple docs match, choose the first one in the specified sort order as the object to manipulate.
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Deprecated

• use findOneAndDelete instead

Returns:

Promise if no callback passed

findOne(query, options, callback){Promise}

lib/collection.js, line 1014

Fetches the first document that matches the query

Name	Type	Description
query	object	Query for find Operation
options	object	optional Optional settings. Name Type Default Description limit number 0 optional Sets the limit of documents returned in the query. sort array | object optional Set to sort the documents coming back from the query. Array of indexes, [['a', 1]] etc. projection object optional The fields to return in the query. Object of fields to include or exclude (not both), {'a':1} fields object optional Deprecated Use options.projection instead skip number 0 optional Set to skip N documents ahead in your query (useful for pagination). hint Object optional Tell the query to use specific indexes in the query. Object of indexes to use, {'_id':1} explain boolean false optional Explain the query instead of returning the data. snapshot boolean false optional DEPRECATED: Snapshot query. timeout boolean false optional Specify if the cursor can timeout. tailable boolean false optional Specify if the cursor is tailable. batchSize number 0 optional Set the batchSize for the getMoreCommand when iterating over the query results. returnKey boolean false optional Only return the index key. maxScan number optional DEPRECATED: Limit the number of items to scan. min number optional Set index bounds. max number optional Set index bounds. showDiskLoc boolean false optional Show disk location of results. comment string optional You can put a $comment field on a query to make looking in the profiler logs simpler. raw boolean false optional Return document results as raw BSON buffers. promoteLongs boolean true optional Promotes Long values to number if they fit inside the 53 bits resolution. promoteValues boolean true optional Promotes BSON values to native types where possible, set to false to only receive wrapper types. promoteBuffers boolean false optional Promotes Binary BSON values to native Node Buffers. readPreference ReadPreference | string optional The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST). partial boolean false optional Specify if the cursor should return partial results when querying against a sharded system maxTimeMS number optional Number of miliseconds to wait before aborting the query. collation object optional Specify collation (MongoDB 3.4 or higher) settings for update operation (see 3.4 documentation for available fields). session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Returns:

Promise if no callback passed

findOneAndDelete(filter, options, callback){Promise.<Collection~findAndModifyWriteOpResultObject>}

lib/collection.js, line 1528

Find a document and delete it in one atomic operation. Requires a write lock for the duration of the operation.

Name	Type	Description
filter	object	The Filter used to select the document to remove
options	object	optional Optional settings. Name Type Description projection object optional Limits the fields to return for all matching documents. sort object optional Determines which document the operation modifies if the query selects multiple documents. maxTimeMS number optional The maximum amount of time to allow the query to run. session ClientSession optional optional session to use for this operation
callback	Collection~findAndModifyCallback	optional The collection result callback

Returns:

Promise if no callback passed

findOneAndReplace(filter, replacement, options, callback){Promise.<Collection~findAndModifyWriteOpResultObject>}

lib/collection.js, line 1555

Find a document and replace it in one atomic operation. Requires a write lock for the duration of the operation.

Name	Type	Description
filter	object	The Filter used to select the document to replace
replacement	object	The Document that replaces the matching document
options	object	optional Optional settings. Name Type Default Description projection object optional Limits the fields to return for all matching documents. sort object optional Determines which document the operation modifies if the query selects multiple documents. maxTimeMS number optional The maximum amount of time to allow the query to run. upsert boolean false optional Upsert the document if it does not exist. returnOriginal boolean true optional When false, returns the updated document rather than the original. The default is true. session ClientSession optional optional session to use for this operation
callback	Collection~findAndModifyCallback	optional The collection result callback

Returns:

Promise if no callback passed

findOneAndUpdate(filter, update, options, callback){Promise.<Collection~findAndModifyWriteOpResultObject>}

lib/collection.js, line 1591

Find a document and update it in one atomic operation. Requires a write lock for the duration of the operation.

Name	Type	Description
filter	object	The Filter used to select the document to update
update	object	Update operations to be performed on the document
options	object	optional Optional settings. Name Type Default Description projection object optional Limits the fields to return for all matching documents. sort object optional Determines which document the operation modifies if the query selects multiple documents. maxTimeMS number optional The maximum amount of time to allow the query to run. upsert boolean false optional Upsert the document if it does not exist. returnOriginal boolean true optional When false, returns the updated document rather than the original. The default is true. session ClientSession optional optional session to use for this operation arrayFilters Array optional optional list of array filters referenced in filtered positional operators
callback	Collection~findAndModifyCallback	optional The collection result callback

Returns:

Promise if no callback passed

geoHaystackSearch(x, y, options, callback){Promise}

lib/collection.js, line 1919

Execute a geo search using a geo haystack index on a collection.

Name	Type	Description
x	number	Point to search on the x axis, ensure the indexes are ordered in the same order.
y	number	Point to search on the y axis, ensure the indexes are ordered in the same order.
options	object	optional Optional settings. Name Type Default Description readPreference ReadPreference | string optional The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST). maxDistance number optional Include results up to maxDistance from the point. search object optional Filter the results by a query. limit number false optional Max number of results to return. session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Returns:

Promise if no callback passed

group(keys, condition, initial, reduce, finalize, command, options, callback){Promise}

lib/collection.js, line 1944

Run a group command across a collection

Name	Type	Description
keys	object | array | function | code	An object, array or function expressing the keys to group by.
condition	object	An optional condition that must be true for a row to be considered.
initial	object	Initial value of the aggregation counter object.
reduce	function | Code	The reduce function aggregates (reduces) the objects iterated
finalize	function | Code	An optional function to be run on each item in the result set just before the item is returned.
command	boolean	Specify if you wish to run using the internal group command or using eval, default is true.
options	object	optional Optional settings. Name Type Description readPreference ReadPreference | string optional The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST). session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Deprecated

• MongoDB 3.6 or higher no longer supports the group command. We recommend rewriting using the aggregation framework.

Returns:

Promise if no callback passed

indexes(options, callback){Promise}

lib/collection.js, line 1476

Retrieve all the indexes on the collection.

Name	Type	Description
options	Object	optional Optional settings Name Type Description session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Returns:

Promise if no callback passed

indexExists(indexes, options, callback){Promise}

lib/collection.js, line 1323

Checks if one or more indexes exist on the collection, fails on first non-existing index

Name	Type	Description
indexes	string | array	One or more index names to check.
options	Object	optional Optional settings Name Type Description session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Returns:

Promise if no callback passed

indexInformation(options, callback){Promise}

lib/collection.js, line 1339

Retrieves this collections index info.

Name	Type	Description
options	object	optional Optional settings. Name Type Default Description full boolean false optional Returns the full raw index information. session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Returns:

Promise if no callback passed

initializeOrderedBulkOp(options, callback){null}

lib/collection.js, line 2084

Initiate an In order bulk write operation. Operations will be serially executed in the order they are added, creating a new operation for each switch in types.

Name	Type	Description
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. session ClientSession optional optional session to use for this operation ignoreUndefined boolean false optional Specify if the BSON serializer should ignore undefined fields.
callback	OrderedBulkOperation	The command result callback

initializeUnorderedBulkOp(options){UnorderedBulkOperation}

lib/collection.js, line 2060

Initiate an Out of order batch write operation. All operations will be buffered into insert/update/remove commands executed out of order.

Name	Type	Description
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. ignoreUndefined boolean false optional Specify if the BSON serializer should ignore undefined fields. session ClientSession optional optional session to use for this operation

insert(docs, options, callback){Promise}

lib/collection.js, line 667

Inserts a single document or a an array of documents into MongoDB. If documents passed in do not contain the _id field,
one will be added to each of the documents missing it by the driver, mutating the document. This behavior
can be overridden by setting the forceServerObjectId flag.

Name	Type	Description
docs	object | Array.<object>	Documents to insert.
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. serializeFunctions boolean false optional Serialize functions on any object. forceServerObjectId boolean false optional Force server to assign _id values instead of driver. bypassDocumentValidation boolean false optional Allow driver to bypass schema validation in MongoDB 3.2 or higher. session ClientSession optional optional session to use for this operation
callback	Collection~insertWriteOpCallback	optional The command result callback

Deprecated

• Use insertOne, insertMany or bulkWrite

Returns:

Promise if no callback passed

insertMany(docs, options, callback){Promise}

lib/collection.js, line 501

Inserts an array of documents into MongoDB. If documents passed in do not contain the _id field,
one will be added to each of the documents missing it by the driver, mutating the document. This behavior
can be overridden by setting the forceServerObjectId flag.

Name	Type	Description
docs	Array.<object>	Documents to insert.
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. serializeFunctions boolean false optional Serialize functions on any object. forceServerObjectId boolean false optional Force server to assign _id values instead of driver. bypassDocumentValidation boolean false optional Allow driver to bypass schema validation in MongoDB 3.2 or higher. ordered boolean true optional If true, when an insert fails, don't execute the remaining writes. If false, continue with remaining inserts when one fails. session ClientSession optional optional session to use for this operation
callback	Collection~insertWriteOpCallback	optional The command result callback

Returns:

Promise if no callback passed

insertOne(doc, options, callback){Promise}

lib/collection.js, line 454

Inserts a single document into MongoDB. If documents passed in do not contain the _id field,
one will be added to each of the documents missing it by the driver, mutating the document. This behavior
can be overridden by setting the forceServerObjectId flag.

Name	Type	Description
doc	object	Document to insert.
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. serializeFunctions boolean false optional Serialize functions on any object. forceServerObjectId boolean false optional Force server to assign _id values instead of driver. bypassDocumentValidation boolean false optional Allow driver to bypass schema validation in MongoDB 3.2 or higher. session ClientSession optional optional session to use for this operation
callback	Collection~insertOneWriteOpCallback	optional The command result callback

Returns:

Promise if no callback passed

isCapped(options, callback){Promise}

lib/collection.js, line 1105

Returns if the collection is a capped collection

Name	Type	Description
options	Object	optional Optional settings Name Type Description session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The results callback

Returns:

Promise if no callback passed

listIndexes(options){CommandCursor}

lib/collection.js, line 1242

Get the list of all indexes information for the collection.

Name	Type	Description
options	object	optional Optional settings. Name Type Description batchSize number optional The batchSize for the returned command cursor or if pre 2.8 the systems batch collection readPreference ReadPreference | string optional The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST). session ClientSession optional optional session to use for this operation

mapReduce(map, reduce, options, callback){Promise}

lib/collection.js, line 2024

Run Map Reduce across a collection. Be aware that the inline option for out will return an array of results not a collection.

Name	Type	Description
map	function | string	The mapping function.
reduce	function | string	The reduce function.
options	object	optional Optional settings. Name Type Default Description readPreference ReadPreference | string optional The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST). out object optional Sets the output target for the map reduce job. {inline:1} | {replace:'collectionName'} | {merge:'collectionName'} | {reduce:'collectionName'} query object optional Query filter object. sort object optional Sorts the input objects using this key. Useful for optimization, like sorting by the emit key for fewer reduces. limit number optional Number of objects to return from collection. keeptemp boolean false optional Keep temporary data. finalize function | string optional Finalize function. scope object optional Can pass in variables that can be access from map/reduce/finalize. jsMode boolean false optional It is possible to make the execution stay in JS. Provided in MongoDB > 2.0.X. verbose boolean false optional Provide statistics on job execution time. bypassDocumentValidation boolean false optional Allow driver to bypass schema validation in MongoDB 3.2 or higher. session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Throws:

MongoError

Returns:

Promise if no callback passed

options(options, callback){Promise}

lib/collection.js, line 1089

Returns the options of the collection.

Name	Type	Description
options	Object	optional Optional settings Name Type Description session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The results callback

Returns:

Promise if no callback passed

parallelCollectionScan(options, callback){Promise}

lib/collection.js, line 1882

Return N number of parallel cursors for a collection allowing parallel reading of entire collection. There are
no ordering guarantees for returned results.

Name	Type	Description
options	object	optional Optional settings. Name Type Default Description readPreference ReadPreference | string optional The preferred read preference (ReadPreference.PRIMARY, ReadPreference.PRIMARY_PREFERRED, ReadPreference.SECONDARY, ReadPreference.SECONDARY_PREFERRED, ReadPreference.NEAREST). batchSize number optional Set the batchSize for the getMoreCommand when iterating over the query results. numCursors number 1 optional The maximum number of parallel command cursors to return (the number of returned cursors will be in the range 1:numCursors) raw boolean false optional Return all BSON documents as Raw Buffer documents.
callback	Collection~parallelCollectionScanCallback	optional The command result callback

Returns:

Promise if no callback passed

reIndex(options, callback){Promise}

lib/collection.js, line 1225

Reindex all indexes on the collection
Warning: reIndex is a blocking operation (indexes are rebuilt in the foreground) and will be slow for large collections.

Name	Type	Description
options	Object	optional Optional settings Name Type Description session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The command result callback

Returns:

Promise if no callback passed

remove(selector, options, callback){Promise}

lib/collection.js, line 926

Remove documents.

Name	Type	Description
selector	object	The selector for the update operation.
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. single boolean false optional Removes the first document found. session ClientSession optional optional session to use for this operation
callback	Collection~writeOpCallback	optional The command result callback

Deprecated

• use deleteOne, deleteMany or bulkWrite

Returns:

Promise if no callback passed

rename(newName, options, callback){Promise}

lib/collection.js, line 1053

Rename the collection.

Name	Type	Description
newName	string	New name of of the collection.
options	object	optional Optional settings. Name Type Default Description dropTarget boolean false optional Drop the target name collection if it previously exists. session ClientSession optional optional session to use for this operation
callback	Collection~collectionResultCallback	optional The results callback

Returns:

Promise if no callback passed

replaceOne(filter, doc, options, callback){Promise.<Collection~updatewriteOpResultObject>}

lib/collection.js, line 754

Replace a document in a collection with another document

Name	Type	Description
filter	object	The Filter used to select the document to replace
doc	object	The Document that replaces the matching document
options	object	optional Optional settings. Name Type Default Description upsert boolean false optional Update operation is an upsert. w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. bypassDocumentValidation boolean false optional Allow driver to bypass schema validation in MongoDB 3.2 or higher. session ClientSession optional optional session to use for this operation
callback	Collection~updateWriteOpCallback	optional The command result callback

Returns:

Promise if no callback passed

save(doc, options, callback){Promise}

lib/collection.js, line 953

Save a document. Simple full document replacement function. Not recommended for efficiency, use atomic
operators and update instead for more efficient operations.

Name	Type	Description
doc	object	Document to save
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. session ClientSession optional optional session to use for this operation
callback	Collection~writeOpCallback	optional The command result callback

Deprecated

• use insertOne, insertMany, updateOne or updateMany

Returns:

Promise if no callback passed

stats(options, callback){Promise}

lib/collection.js, line 1493

Get all the collection statistics.

Name	Type	Description
options	object	optional Optional settings. Name Type Description scale number optional Divide the returned sizes by scale value. session ClientSession optional optional session to use for this operation
callback	Collection~resultCallback	optional The collection result callback

Returns:

Promise if no callback passed

update(selector, update, options, callback){Promise}

lib/collection.js, line 823

Updates documents.

Name	Type	Description
selector	object	The selector for the update operation.
update	object	The update operations to be applied to the documents
options	object	optional Optional settings. Name Type Default Description w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. upsert boolean false optional Update operation is an upsert. multi boolean false optional Update one/all documents with operation. bypassDocumentValidation boolean false optional Allow driver to bypass schema validation in MongoDB 3.2 or higher. collation object optional Specify collation (MongoDB 3.4 or higher) settings for update operation (see 3.4 documentation for available fields). arrayFilters Array optional optional list of array filters referenced in filtered positional operators session ClientSession optional optional session to use for this operation
callback	Collection~writeOpCallback	optional The command result callback

Deprecated

• use updateOne, updateMany or bulkWrite

Throws:

MongoError

Returns:

Promise if no callback passed

updateMany(filter, update, options, callback){Promise.<Collection~updateWriteOpResultObject>}

lib/collection.js, line 782

Update multiple documents in a collection

Name	Type	Description
filter	object	The Filter used to select the documents to update
update	object	The update operations to be applied to the documents
options	object	optional Optional settings. Name Type Default Description upsert boolean false optional Update operation is an upsert. w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. arrayFilters Array optional optional list of array filters referenced in filtered positional operators session ClientSession optional optional session to use for this operation
callback	Collection~updateWriteOpCallback	optional The command result callback

Returns:

Promise if no callback passed

updateOne(filter, update, options, callback){Promise}

lib/collection.js, line 718

Update a single document in a collection

Name	Type	Description
filter	object	The Filter used to select the document to update
update	object	The update operations to be applied to the document
options	object	optional Optional settings. Name Type Default Description upsert boolean false optional Update operation is an upsert. w number | string optional The write concern. wtimeout number optional The write concern timeout. j boolean false optional Specify a journal write concern. bypassDocumentValidation boolean false optional Allow driver to bypass schema validation in MongoDB 3.2 or higher. arrayFilters Array optional optional list of array filters referenced in filtered positional operators session ClientSession optional optional session to use for this operation
callback	Collection~updateWriteOpCallback	optional The command result callback

Returns:

Promise if no callback passed

watch(pipeline, options){ChangeStream}

lib/collection.js, line 1850

Create a new Change Stream, watching for new changes (insertions, updates, replacements, deletions, and invalidations) in this collection.

Name	Type	Description
pipeline	Array	optional An array of aggregation pipeline stages through which to pass change stream documents. This allows for filtering (using $match) and manipulating the change stream documents.
options	object	optional Optional settings Name Type Default Description fullDocument string 'default' optional Allowed values: ‘default’, ‘updateLookup’. When set to ‘updateLookup’, the change stream will include both a delta describing the changes to the document, as well as a copy of the entire document that was changed from some time after the change occurred. resumeAfter object optional Specifies the logical starting point for the new change stream. This should be the _id field from a previously returned change stream document. maxAwaitTimeMS number optional The maximum amount of time for the server to wait on new documents to satisfy a change stream query batchSize number optional The number of documents to return per batch. See aggregation documentation. collation object optional Specify collation settings for operation. See aggregation documentation. readPreference ReadPreference optional The read preference. Defaults to the read preference of the database or collection. See read preference documentation. startAtClusterTime Timestamp optional receive change events that occur after the specified timestamp session ClientSession optional optional session to use for this operation

Since:

• 3.0.0

Returns:

ChangeStream instance.

Type Definitions

aggregationCallback(error, cursor)

lib/collection.js, line 973

The callback format for an aggregation call

Name	Type	Description
error	MongoError	An error instance representing the error during the execution.
cursor	AggregationCursor	The cursor if the aggregation command was executed successfully.

bulkWriteOpCallback(error, result)

lib/collection.js, line 546

The callback format for inserts

Name	Type	Description
error	BulkWriteError	An error instance representing the error during the execution.
result	Collection~BulkWriteOpResult	The result object if the command was executed successfully.

BulkWriteOpResultObject

Properties:

Name	Type	Description
insertedCount	number	Number of documents inserted.
matchedCount	number	Number of documents matched for update.
modifiedCount	number	Number of documents modified.
deletedCount	number	Number of documents deleted.
upsertedCount	number	Number of documents upserted.
insertedIds	object	Inserted document generated Id's, hash key is the index of the originating operation
upsertedIds	object	Upserted document generated Id's, hash key is the index of the originating operation
result	object	The command result object.

collectionResultCallback(error, collection)

lib/collection.js, line 1035

The callback format for the collection method, must be used if strict is specified

Name	Type	Description
error	MongoError	An error instance representing the error during the execution.
collection	Collection	The collection instance.

countCallback(error, result)

lib/collection.js, line 1347

The callback format for results

Name	Type	Description
error	MongoError	An error instance representing the error during the execution.
result	number	The count of documents that matched the query.

deleteWriteOpCallback(error, result)

lib/collection.js, line 851

The callback format for inserts

Name	Type	Description
error	MongoError	An error instance representing the error during the execution.
result	Collection~deleteWriteOpResult	The result object if the command was executed successfully.

deleteWriteOpResultObject

Properties:

Name	Type	Description
result	Object	The raw result returned from MongoDB. Will vary depending on server version. Properties Name Type Description ok Number Is 1 if the command executed correctly. n Number The total count of documents deleted.
connection	Object	The connection object used for the operation.
deletedCount	Number	The number of documents deleted.

findAndModifyCallback(error, result)

lib/collection.js, line 1508

The callback format for inserts

Name	Type	Description
error	MongoError	An error instance representing the error during the execution.
result	Collection~findAndModifyWriteOpResult	The result object if the command was executed successfully.

findAndModifyWriteOpResultObject

Properties:

Name	Type	Description
value	object	Document returned from findAndModify command.
lastErrorObject	object	The raw lastErrorObject returned from the command.
ok	Number	Is 1 if the command executed correctly.

insertOneWriteOpCallback(error, result)

lib/collection.js, line 641

The callback format for inserts

Name	Type	Description
error	MongoError	An error instance representing the error during the execution.
result	Collection~insertOneWriteOpResult	The result object if the command was executed successfully.

insertOneWriteOpResultObject

Properties:

Name	Type	Description
insertedCount	Number	The total amount of documents inserted.
ops	Array.<object>	All the documents inserted using insertOne/insertMany/replaceOne. Documents contain the _id field if forceServerObjectId == false for insertOne/insertMany
insertedId	ObjectId	The driver generated ObjectId for the insert operation.
connection	object	The connection object used for the operation.
result	object	The raw command result object returned from MongoDB (content might vary by server version). Properties Name Type Description ok Number Is 1 if the command executed correctly. n Number The total count of documents inserted.

insertWriteOpCallback(error, result)

lib/collection.js, line 634

The callback format for inserts

Name	Type	Description
error	MongoError	An error instance representing the error during the execution.
result	Collection~insertWriteOpResult	The result object if the command was executed successfully.

insertWriteOpResultObject

Properties:

Name	Type	Description
insertedCount	Number	The total amount of documents inserted.
ops	Array.<object>	All the documents inserted using insertOne/insertMany/replaceOne. Documents contain the _id field if forceServerObjectId == false for insertOne/insertMany
insertedIds	Object.<Number, ObjectId>	Map of the index of the inserted document to the id of the inserted document.
connection	object	The connection object used for the operation.
result	object	The raw command result object returned from MongoDB (content might vary by server version). Properties Name Type Description ok Number Is 1 if the command executed correctly. n Number The total count of documents inserted.

parallelCollectionScanCallback(error, cursors)

lib/collection.js, line 1863

The callback format for results

Name	Type	Description
error	MongoError	An error instance representing the error during the execution.
cursors	Array.<Cursor>	A list of cursors returned allowing for parallel reading of collection.

resultCallback(error, result)

lib/collection.js, line 966

The callback format for results

Name	Type	Description
error	MongoError	An error instance representing the error during the execution.
result	object	The result object if the command was executed successfully.

updateWriteOpCallback(error, result)

lib/collection.js, line 695

The callback format for inserts

Name	Type	Description
error	MongoError	An error instance representing the error during the execution.
result	Collection~updateWriteOpResult	The result object if the command was executed successfully.

updateWriteOpResultObject

Properties:

Name	Type	Description
result	Object	The raw result returned from MongoDB. Will vary depending on server version. Properties Name Type Description ok Number Is 1 if the command executed correctly. n Number The total count of documents scanned. nModified Number The total count of documents modified.
connection	Object	The connection object used for the operation.
matchedCount	Number	The number of documents that matched the filter.
modifiedCount	Number	The number of documents that were modified.
upsertedCount	Number	The number of documents upserted.
upsertedId	Object	The upserted id. Properties Name Type Description _id ObjectId The upserted _id returned from the server.
message	Object
ops	Array

writeOpCallback(error, result)

lib/collection.js, line 605

The callback format for inserts

Name	Type	Description
error	MongoError	An error instance representing the error during the execution.
result	Collection~WriteOpResult	The result object if the command was executed successfully.

WriteOpResultObject

Properties:

Name	Type	Description
ops	Array.<object>	All the documents inserted using insertOne/insertMany/replaceOne. Documents contain the _id field if forceServerObjectId == false for insertOne/insertMany
connection	object	The connection object used for the operation.
result	object	The command result object.