mongodbext

This is extension for node-mongodb-native that imports patched collection object and allows to add hooks on write operations, such as insert, update and delete. It also adds some options to this operations, that allows to modify operation's result.

Important since version 3.0.0 mongodb drivers of versions 2.x.x are no longer supported.

Installation

npm install mongodbext

Usage

new Collection(db, collectionName, options)

Creates new instance of collection

Parameters:

All parameters described as name, type, default value.

• db, object. Database instance

• collectionName, string. Name of collection.

• options, object, null. Optional settings.

  • changeDataMethods, Array, null. Set supported data changing methods. If not set all methods are supported.
  • customCountImplementation, boolean, null. Starting from 4.0 MongoDB deprecates count method in favor of countDocuments and estimatedDocumentCount. Setting customCountImplementation to true allows you to use under the hood of count either countDocuments if query predicate exists or estimatedDocumentCount if no query predicate provided.

Returns:

Instance of collection

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'constructorExample');

	collection.insertOne({a: 1}, function(err) {
		expect(err).not.ok();
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'constructorExample', {
		changeDataMethods: ['insertMany']
	});

	collection.insertOne({a: 1}, function(err) {
		expect(err).ok();
		expect(err.name).equal('MongoError');
		expect(err.message).equal('Method "insertOne" for collection "test" is not supported');
	});
});

Collection methods

Methods marked as deprecated are not present in documentation.

• aggregate(pipeline, options, callback)
• bulkWrite(operations, options, callback)
• count(query, options, callback)
• countDocuments(query, options, callback)
• createIndex(fieldOrSpec, options, callback)
• createIndexes(indexSpecs, options, callback)
• deleteMany(filter, options, callback)
• deleteOne(filter, options, callback)
• distinct(key, query, options, callback)
• drop(options, callback)
• dropIndex(indexName, options, callback)
• dropIndexes(options, callback)
• estimatedDocumentCount(options, callback)
• find(query, projection)
• findOne(query, projection, callback)
• findOneAndDelete(filter, options, callback)
• findOneAndReplace(filter, replacement, options, callback)
• findOneAndUpdate(filter, update, options, callback)
• findOneAndUpsert(filter, update, options, callback)
• indexes(options, callback)
• indexExists(indexes, options, callback)
• indexInformation(options, callback)
• initializeOrderedBulkOp(options)
• initializeUnorderedBulkOp(options)
• insertMany(docs, options, callback)
• insertOne(doc, options, callback)
• isCapped(options, callback)
• listIndexes(options)
• mapReduce(map, reduce, options, callback)
• options(options, callback)
• parallelCollectionScan(options, callback)
• rename(newName, options, callback)
• replaceOne(filter, doc, options, callback)
• stats(options, callback)
• updateMany(filter, update, options, callback)
• updateOne(filter, update, options, callback)
• watch(pipeline, options)

deleteMany(filter, options, callback)

Delete multiple documents on MongoDB

Parameters:

All parameters described as name, type, default value.

• filter, object. The Filter used to select the documents to remove

• options, object, null. Optional settings.

  • w, number or string, null. The write concern.

  • wtimeout, number, null. The write concern timeout.

  • j, boolean, false. Specify a journal write concern.

  • returnResultOnly, boolean, true. Specifying result returning in callback.

• callback, function. The command result callback

Returns:

Promise if no callback passed

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'deleteManyExample');

	collection.insertMany([{
		a: 1
	}, {
		a: 2
	}], function(err, insertResult) {
		collection.deleteMany({}, function(err, deleteManyResult) {
			expect(deleteManyResult).only.keys('deletedCount');
		});
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'deleteManyExample');

	collection.insertMany([{
		a: 1
	}, {
		a: 2
	}], function(err, insertResult) {
		collection.deleteMany({}, {
			returnDocsOnly: false
		}, function(err, deleteManyResult) {
			expect(deleteManyResult).only.keys(
				'connection', 'result', 'deletedCount'
			);
		});
	});
});

deleteOne(filter, options, callback)

Delete a document on MongoDB

Parameters:

All parameters described as name, type, default value.

• filter, object. The Filter used to select the documents to remove

• options, object, null. Optional settings.

  • w, number or string, null. The write concern.

  • wtimeout, number, null. The write concern timeout.

  • j, boolean, false. Specify a journal write concern.

  • bypassDocumentValidation, boolean, false. Allow driver to bypass schema validation in MongoDB 3.2 or higher.

  • returnResultOnly, boolean, true. Specifying result returning in callback.

• callback, function. The command result callback

Returns:

Promise if no callback passed

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'deleteOneExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.deleteOne({}, function(err, deleteOneResult) {
			expect(deleteOneResult).only.keys('deletedCount');
		});
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'deleteOneExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.deleteOne({}, {
			returnDocsOnly: false
		}, function(err, deleteOneResult) {
			expect(deleteOneResult).only.keys(
				'connection', 'result', 'deletedCount'
			);
		});
	});
});

find(query, projection)

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

Parameters:

All parameters described as name, type, default value.

• filter, object. The Cursor query object.

• projection, object, null. The field projection object.

Returns:

Cursor

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'findExample');

	collection.insertMany([{
		a: 1
	}, {
		a: 2
	}], function(err, insertResult) {
		collection.find({}, {
			_id: 0
		}).toArray(function(err, findResult) {
			findResult.forEach(function(obj) {
				expect(obj).not.key('_id');
			});
		});
	});
});

findOne(query, projection, callback)

Fetches the first document that matches the query

Parameters:

All parameters described as name, type, default value.

• filter, object. Query for find Operation.

• projection, object, null. The field projection object.

• callback, function. The command result callback

Returns:

Promise if no callback passed

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'findOneExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.findOne({}, {
			_id: 0
		}, function(err, findOneResult) {
			expect(findOneResult).eql({a: 1});
		});
	});
});

findOneAndDelete(filter, options, callback)

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

Parameters:

All parameters described as name, type, default value.

• filter, object. Document selection filter.

• options, object, null. Optional settings.

  • projection, object, null. Limits the fields to return for all matching documents.

  • sort, object, null. Determines which document the operation modifies if the query selects multiple documents.

  • maxTimeMS, number, null. The maximum amount of time to allow the query to run.

  • returnDocsOnly, boolean, true. When true returns only result document.

• callback, function. The collection result callback.

Returns:

Promise if no callback passed

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'findOneAndDeleteExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.findOneAndDelete({
			_id: insertResult._id
		}, function(err, deleteResult) {
			expect(deleteResult).eql(insertResult);
		});
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'findOneAndDeleteExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.findOneAndDelete({
			_id: insertResult._id
		}, {
			returnDocsOnly: false
		}, function(err, deleteResult) {
			expect(deleteResult).keys(
				'value', 'ok', 'lastErrorObject'
			);
		});
	});
});

findOneAndReplace(filter, replacement, options, callback)

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

Parameters:

All parameters described as name, type, default value.

• filter, object. Document selection filter.

• replacement, object. Document replacing the matching document.

• options, object, null. Optional settings.

  • projection, object, null. Limits the fields to return for all matching documents.

  • sort, object, null. Determines which document the operation modifies if the query selects multiple documents.

  • maxTimeMS, number, null. The maximum amount of time to allow the query to run.

  • returnOriginal, boolean, true. When false, returns the updated document rather than the original.

  • returnDocsOnly, boolean, true. When true returns only result document.

• callback, function. The collection result callback.

Returns:

Promise if no callback passed

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'findOneAndReplaceExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.findOneAndReplace({
			_id: insertResult._id
		}, {
			a: 2
		}, function(err, replaceResult) {
			expect(replaceResult).eql(insertResult);
		});
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'findOneAndReplaceExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.findOneAndReplace({
			_id: insertResult._id
		}, {
			a: 2
		}, {
			returnDocsOnly: false
		}, function(err, replaceResult) {
			expect(replaceResult).keys(
				'value', 'ok', 'lastErrorObject'
			);
		});
	});
});

findOneAndUpdate(filter, update, options, callback)

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

Parameters:

All parameters described as name, type, default value.

• filter, object. Document selection filter.

• update, object. Update operations to be performed on the document

• options, object, null. Optional settings.

  • projection, object, null. Limits the fields to return for all matching documents.

  • sort, object, null. Determines which document the operation modifies if the query selects multiple documents.

  • maxTimeMS, number, null. The maximum amount of time to allow the query to run.

  • returnOriginal, boolean, true. When false, returns the updated document rather than the original.

  • returnDocsOnly, boolean, true. When true returns only result document.

• callback, function. The collection result callback

Returns:

Promise if no callback passed

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'findOneAndUpdateExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.findOneAndUpdate({
			_id: insertResult._id
		}, {
			$inc: {a: 1}
		}, function(err, updateResult) {
			expect(updateResult).eql(insertResult);
		});
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'findOneAndUpdateExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.findOneAndUpdate({
			_id: insertResult._id
		}, {
			$inc: {a: 1}
		}, {
			returnDocsOnly: false
		}, function(err, updateResult) {
			expect(updateResult).keys(
				'value', 'ok', 'lastErrorObject'
			);
		});
	});
});

findOneAndUpsert(filter, update, options, callback)

Upsert a single document on MongoDB.

⚠️ Important. Uses findOneAnReplace and findOneAndUpdate with upsert option under the hood. findOneAndReplace will be used, if update parameter do not contain any update operators (basically, fields begins with $). It can lead to slightly inconsistent behavior, depending on input data. (see db.collection.findOneAndReplace-upsert and db.collection.update upsert behavior to clarify behavior difference). Because of realization it's strongly not recommended using this method on collection with sequenceId and updateDate plugins.

Parameters:

• filter, object. The Filter used to select the document to upsert

• update, object. The update operations or replacement document to be applied to the document

• options, object, null. Optional settings.

  • projection, object, null. Limits the fields to return for all matching documents.

  • sort, object, null. Determines which document the operation modifies if the query selects multiple documents.

  • maxTimeMS, number, null. The maximum amount of time to allow the query to run.

  • returnOriginal, boolean, true. When false, returns the updated document rather than the original.

  • returnDocsOnly, boolean, true. When true returns only result document.

• callback, function. The command result callback

Returns:

Promise if no callback passed

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'findOneAndUpsertExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.findOneAndUpsert({
			_id: insertResult._id
		}, {
			$inc: {a: 1}
		}, function(err, upsertResult) {
			expect(upsertResult).eql(insertResult);
		});
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'findOneAndUpsertExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.findOneAndUpsert({
			_id: insertResult._id
		}, {
			$inc: {a: 1}
		}, {
			returnDocsOnly: false
		}, function(err, upsertResult) {
			expect(upsertResult).keys(
				'value', 'ok', 'lastErrorObject'
			);
		});
	});
});

insertMany(docs, options, callback)

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.

Parameters:

All parameters described as name, type, default value.

• docs, Array. Documents to insert.

• options, object, null. Optional settings.

  • w, number | string, null. The write concern.

  • wtimeout, number, null. The write concern timeout.

  • j, boolean, false. Specify a journal write concern.

  • serializeFunctions, boolean, false. Serialize functions on any object.

  • forceServerObjectId, boolean, false. Force server to assign _id values instead of driver.

  • returnDocsOnly, boolean, true. When true returns only result documents.

• callback, function. The command result callback

Returns:

Promise if no callback passed

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'insertManyExample');

	var documents = [{_id: 1, a: 1}, {_id: 2, a: 2}];
	collection.insertMany(documents, function(err, insertResult) {
		expect(insertResult).eql(documents);
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'insertManyExample');

	var documents = [{_id: 1, a: 1}, {_id: 2, a: 2}];
	collection.insertMany(documents, {
		returnDocsOnly: false
	}, function(err, insertResult) {
		expect(insertResult).keys(
			'result', 'ops', 'insertedCount', 'insertedIds'
		);
		expect(insertResult.ops).eql(documents);
	});
});

insertOne(doc, options, callback)

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.

Parameters:

All parameters described as name, type, default value.

• doc, object. Document to insert.

• options, object, null. Optional settings.

  • w, number | string, null. The write concern.

  • wtimeout, number, null. The write concern timeout.

  • j, boolean, false. Specify a journal write concern.

  • serializeFunctions, boolean, false. Serialize functions on any object.

  • forceServerObjectId, boolean, false. Force server to assign _id values instead of driver.

  • bypassDocumentValidation, boolean, false. Allow driver to bypass schema validation in MongoDB 3.2 or higher.

  • returnDocsOnly, boolean, true. When true returns only result document.

• callback, function. The command result callback.

Returns:

Promise if no callback passed.

Examples

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'insertOneExample');

	var document = {_id: 1, a: 1};
	collection.insertOne(document, function(err, insertResult) {
		expect(insertResult).eql(document);
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'insertOneExample');

	var documents = {_id: 1, a: 1};
	collection.insertOne(documents, {
		returnDocsOnly: false
	}, function(err, insertResult) {
		expect(insertResult).keys(
			'result', 'ops', 'insertedCount', 'insertedId', 'connection'
		);
		expect(insertResult.ops).eql([document]);
	});
});

replaceOne(filter, doc, options, callback)

Replace a document on MongoDB

Parameters:

All parameters described as name, type, default value.

• filter, object. The Filter used to select the document to update

• doc, object. The Document that replaces the matching document

• options, object, null. Optional settings.

  • w, number | string, null. The write concern.

  • wtimeout, number, null. The write concern timeout.

  • j, boolean, false. Specify a journal write concern.

  • bypassDocumentValidation, boolean, false. Allow driver to bypass schema validation in MongoDB 3.2 or higher.

  • returnResultOnly, boolean, true. Specifying result returning in callback.

• callback, function. The command result callback.

Returns:

Promise if no callback passed.

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'replaceOneExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.replaceOne({
			_id: insertResult._id
		}, {
			a: 2
		}, function(err, replaceResult) {
			expect(replaceResult).keys(
				'matchedCount', 'modifiedCount', 'upsertedId'
			);
		});
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'replaceOneExample');

	collection.insertOne({
		a: 1
	}, function(err, insertResult) {
		collection.replaceOne({
			_id: insertResult._id
		}, {
			a: 2
		}, {
			returnDocsOnly: false
		}, function(err, replaceResult) {
			expect(replaceResult).keys(
				'result', 'connection', 'matchedCount', 'modifiedCount',
				'upsertedId', 'upsertedCount', 'ops'
			);
		});
	});
});

updateMany(filter, update, options, callback)

Update multiple documents on MongoDB

Parameters:

All parameters described as name, type, default value.

• filter, object. The Filter used to select the document to update

• update, object. The update operations to be applied to the document

• options, object, null. Optional settings.

  • w, number | string, null. The write concern.

  • wtimeout, number, null. The write concern timeout.

  • j, boolean, false. Specify a journal write concern.

  • returnResultOnly, boolean, true. Specifying result returning in callback.

• callback, function. The command result callback

Returns:

Promise if no callback passed.

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'updateManyExample');

	var documents = [{_id: 1, a: 1}, {_id: 2, a: 1}];
	collection.insertMany(documents, function(err, insertResult) {
		collection.updateMany({
			a: 1
		}, {
			a: {$inc: 1}
		}, function(err, updateResult) {
			expect(updateResult).keys(
				'matchedCount', 'modifiedCount', 'upsertedId'
			);
		});
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'updateManyExample');

	var documents = [{_id: 1, a: 1}, {_id: 2, a: 1}];
	collection.insertMany(documents, function(err, insertResult) {
		collection.updateMany({
			a: 1
		}, {
			a: {$inc: 1}
		}, {
			returnResultOnly: false
		}, function(err, updateResult) {
			expect(updateResult).keys(
				'connection', 'result', 'matchedCount', 'modifiedCount',
				'upsertedId', 'upsertedCount'
			);
		});
	});
});

updateOne(filter, update, options, callback)

Update a single document on MongoDB

Parameters:

• filter, object. The Filter used to select the document to update

• update, object. The update operations to be applied to the document

• options, object, null. Optional settings.

  • w, number | string, null. The write concern.

  • wtimeout, number, null, The write concern timeout.

  • j, boolean, false. Specify a journal write concern.

  • bypassDocumentValidation, boolean, false. Allow driver to bypass schema validation in MongoDB 3.2 or higher.

  • returnResultOnly, boolean, true. Specifying result returning in callback.

• callback, function. The command result callback

Returns:

Promise if no callback passed.

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'updateOneExample');

	var document = {_id: 1, a: 1};
	collection.insertOne(document, function(err, insertResult) {
		collection.updateOne({
			a: 1
		}, {
			a: {$inc: 1}
		}, function(err, updateResult) {
			expect(updateResult).keys(
				'matchedCount', 'modifiedCount', 'upsertedId'
			);
		});
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection,
	expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'updateOneExample');

	var document = {_id: 1, a: 1};
	collection.insertOne(document, function(err, insertResult) {
		collection.updateOne({
			a: 1
		}, {
			a: {$inc: 1}
		}, {
			returnResultOnly: false
		}, function(err, updateResult) {
			expect(updateResult).keys(
				'connection', 'result', 'matchedCount', 'modifiedCount',
				'upsertedId', 'upsertedCount'
			);
		});
	});
});

count(query, options, callback)

Returns the count of documents that would match a query.

Parameters:

• query, object. The Filter used to select the document to upsert. Optional.

• options, object, null. Optional settings.

  • limit, integer. The maximum number of documents to count.

  • skip, integer. The number of documents to skip before counting.

  • hint, string or object. An index name hint or specification for the query.

  • maxTimeMS, integer. The maximum amount of time to allow the query to run.

  • readConcern, string, default to local. Specifies the read concern.

• callback, function. The command result callback

Returns:

Promise if no callback passed

Examples:

var MongoClient = require('mongodb').MongoClient;
var Collection = require('mongodbext').Collection;
var expect = require('expect.js');

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'countExample');

	collection.insertMany([{
		a: 1
	}, {
		a: 2
	}], function() {
		collection.count({
			a: 1
		}, function(err, countResult) {
			expect(countResult).equal(1);
		});
	});
});

Hooks

All hooks take two parameters: params and callback. Callback is always callback function, and params fields depends on hook.

Name	Methods	Params fields
beforeInsertOne	insertOne	obj, document to insert options, optional settings
afterInsertOne	insertOne	obj, inserted document options, optional settings
beforeInsertMany	insertMany	objs, documents to insert options, optional settings
afterInsertMany	insertMany	objs, inserted documents options, optional settings
beforeUpdateOne	updateOne findOneAndUpdate	condition, query to select documents modifier, update operations options, optional settings
afterUpdateOne	updateOne findOneAndUpdate	condition, query to select documents modifier, update operations options, optional settings result, operation result
beforeUpdateMany	updateMany	condition, query to select documents modifier, update operations options, optional settings
afterUpdateMany	updateMany	condition, query to select documents modifier, update operations options, optional settings result, operation result
beforeDeleteOne	deleteOne findOneAndDelete	condition, query to select documents options, optional settings
afterDeleteOne	deleteOne findOneAndDelete	condition, query to select documents options, optional settings result, operation result
beforeDeleteMany	deleteMany	condition, query to select documents options, optional settings
afterDeleteMany	deleteMany	condition, query to select documents options, optional settings result, operation result
beforeReplaceOne	replaceOne findOneAndReplace	condition, query to select documents replacement, document to replace original options, optional settings
afterReplaceOne	replaceOne findOneAndReplace	condition, query to select documents replacement, document to replace original options, optional settings result, operation result
beforeUpsertOne	findOneAndUpsert	condition, query to select documents modifier, update operations options, optional settings
afterUpsertOne	findOneAndUpsert	condition, query to select documents modifier, update operations options, optional settings obj, upserted document isUpdated, flag indicating whether document was updated or inserted

Plugins

Collection class allows to create and use plugins for adding auto-generated fields to documents, for example.

addPlugin(plugin, options)

Add plugin to collection.

Parameters:

• plugin, function | string. It can be either plugin function, or in case of built-in plugins it's name. Plugin function takes collection object as first parameter and optional options as second

• options, object, null. Options that will be passed to plugin.

Examples:

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection;

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'updateOneExample');

	collection.addPlugin(function(collection) {
		collection.on('insertOne', function(params, callback) {
			params.obj.counter = 1;
			callback();
		});
	});
});

var MongoClient = require('mongodb').MongoClient,
	Collection = require('mongodbext').Collection;

MongoClient.connect('mongodb://localhost:27017/test', function(err, db) {
	var collection = new Collection(db, 'updateOneExample');

	collection.addPlugin('sequenceId');
	collection.addPlugin('unsupportedMethods', {
		methods: ['insertMany', 'updateMany']
	});
});

Built-in plugins

sequenceId

Replace mongo-style object _id with number.

⚠️ Do not work with findOneAndUpsert().

options:

• seqCollectionName - name of sequences collection ('__sequences' by default)
• seqName - name of sequence (collection name by default)
• key - key in document to set sequence value (_id by default)

createDate

Add createDate to each inserted to collection document

options:

• format - date format that will be used as createDate, available values:
  • 'timestamp' (default) - integer timestamp date in milliseconds (.getTime())
  • 'string' - string date (.toString())
  • 'ISOString' - string date in ISO format (.toISOString())
  • 'ISODate' - date as Date object (new Date())
  • function(date) - custom user function that should return formatted date

updateDate

Add updateDate to each updated or replaces document

⚠️ Do not work properly with findOneAndUpsert(), createDate will be rewrote every time.

options:

• format - date format that will be used as updateDate, available values:
  • 'timestamp' (default) - integer timestamp date in milliseconds (.getTime())
  • 'string' - string date (.toString())
  • 'ISOString' - string date in ISO format (.toISOString())
  • 'ISODate' - date as Date object (new Date())
  • function(date) - custom user function that should return formatted date

detailedError

Add field operation with query info to error object