Model

Schema

Document

Query

Aggregate

Schematype

Error

DocumentArrayPath

Parameters

  • doc «Object» values for initial set

  • optional «[fields]» object containing the fields that were selected in the query which returned this document. You do not need to set this parameter to ensure Mongoose handles your .

  • [skipId=false] «Boolean» optional boolean. If true, mongoose doesn’t add an field to the document.

Inherits:
  • «Document

A Model is a class that’s your primary tool for interacting with MongoDB. An instance of a Model is called a Document.

In Mongoose, the term “Model” refers to subclasses of the mongoose.Model class. You should not use the mongoose.Model class directly. The and connection.model() functions create subclasses of mongoose.Model as shown below.

Example:

Parameters

  • [pipeline] «Array» aggregation pipeline as an array of objects

  • [options] «Object» aggregation options

  • [callback] «Function»

Returns:
  • «Aggregate»

Performs aggregations on the models collection.

If a callback is passed, the aggregate is executed and a Promise is returned. If a callback is not passed, the aggregate itself is returned.

This function triggers the following middleware.

  • aggregate()

Example:

  1. // Find the max balance of all accounts
  2.   { $group: { _id: null, maxBalance: { $max: '$balance' }}},
  3.   { $project: { _id: 0, maxBalance: 1 }}
  4. ]);
  6. console.log(res); // [ { maxBalance: 98000 } ]
  8. // Or use the aggregation pipeline builder.
  9. const res = await Users.aggregate().
  10.   group({ _id: null, maxBalance: { $max: '$balance' } }).
  11.   project('-id maxBalance').
  12.   exec();
  13. console.log(res); // [ { maxBalance: 98 } ]

NOTE:

  • Mongoose does not cast aggregation pipelines to the model’s schema because $project and $group operators allow redefining the “shape” of the documents at any stage of the pipeline, which may leave documents in an incompatible format. You can use the to enable minimal casting for aggregation pipelines.
  • The documents returned are plain javascript objects, not mongoose documents (since any shape of document can be returned).

More About Aggregations:

Parameters
  • options «Object»
  • options.skipValidation «Boolean» defaults to false, when set to true, building the write operations will bypass validating the documents.

@param {[Document]} documents The array of documents to build write operations of

Model.bulkSave()

Parameters
  • documents «[Document]»

takes an array of documents, gets the changes and inserts/updates documents in the database according to whether or not the document is new, or whether it has changes or not.

bulkSave uses bulkWrite under the hood, so it’s mostly useful when dealing with many documents (10K+)

Parameters

  • ops «Array»

  • [ops.insertOne.document] «Object» The document to insert

  • [opts.updateOne.filter] «Object» Update the first document that matches this filter

  • [opts.updateOne.update] «Object» An object containing

  • [opts.updateOne.upsert=false] «Boolean» If true, insert a doc if none match

  • [opts.updateOne.timestamps=true] «Boolean» If false, do not apply timestamps to the operation

  • [opts.updateOne.collation] «Object» The to use

  • [opts.updateOne.arrayFilters] «Array» The array filters used in update

  • [opts.updateMany.filter] «Object» Update all the documents that match this filter

  • [opts.updateMany.update] «Object» An object containing

  • [opts.updateMany.upsert=false] «Boolean» If true, insert a doc if no documents match filter

  • [opts.updateMany.timestamps=true] «Boolean» If false, do not apply timestamps to the operation

  • [opts.updateMany.collation] «Object» The to use

  • [opts.updateMany.arrayFilters] «Array» The array filters used in update

  • [opts.deleteOne.filter] «Object» Delete the first document that matches this filter

  • [opts.deleteMany.filter] «Object» Delete all documents that match this filter

  • [opts.replaceOne.filter] «Object» Replace the first document that matches this filter

  • [opts.replaceOne.replacement] «Object» The replacement document

  • [opts.replaceOne.upsert=false] «Boolean» If true, insert a doc if no documents match filter

  • [options] «Object»

  • [options.ordered=true] «Boolean» If true, execute writes in order and stop at the first error. If false, execute writes in parallel and continue until all writes have either succeeded or errored.

  • [options.session=null] «ClientSession» The session associated with this bulk write. See .

  • [options.w=1] «String|number» The write concern. See for more information.

  • [options.wtimeout=null] «number» The write concern timeout.

  • [options.j=true] «Boolean» If false, disable

  • [options.bypassDocumentValidation=false] «Boolean» If true, disable MongoDB server-side schema validation for all writes in this bulk.

  • [options.strict=null] «Boolean» Overwrites the on schema. If false, allows filtering and writing fields not defined in the schema for all writes in this bulk.

  • [callback] «Function» callback function(error, bulkWriteOpResult) {}

Returns:
  • «Promise» resolves to a if the operation succeeds

Sends multiple insertOne, updateOne, updateMany, replaceOne, deleteOne, and/or deleteMany operations to the MongoDB server in one command. This is faster than sending multiple independent operations (e.g. if you use create()) because with bulkWrite() there is only one round trip to MongoDB.

Mongoose will perform casting on all operations you provide.

This function does not trigger any middleware, neither save(), nor update(). If you need to trigger save() middleware for every document use create() instead.

Example:

  1. Character.bulkWrite([
  2.   {
  3.     insertOne: {
  4.       document: {
  5.         name: 'Eddard Stark',
  6.         title: 'Warden of the North'
  7.       }
  8.     }
  9.   },
  10.   {
  11.     updateOne: {
  12.       filter: { name: 'Eddard Stark' },
  13.       // If you were using the MongoDB driver directly, you'd need to do
  14.       // `update: { $set: { title: ... } }` but mongoose adds $set for
  15.       // you.
  16.       update: { title: 'Hand of the King' }
  17.     }
  18.   },
  19.   {
  20.     deleteOne: {
  21.       {
  22.         filter: { name: 'Eddard Stark' }
  23.       }
  24.     }
  25.   }
  26. ]).then(res => {
  27.  // Prints "1 1 1"
  28.  console.log(res.insertedCount, res.modifiedCount, res.deletedCount);
  29. });

The supported operations are:

  • insertOne
  • updateOne
  • updateMany
  • deleteOne
  • deleteMany
  • replaceOne

Model.cleanIndexes()

Parameters
  • [callback] «Function» optional callback
Returns:
  • «Promise,undefined» Returns undefined if callback is specified, returns a promise if no callback.

Deletes all indexes that aren’t defined in this model’s schema. Used by syncIndexes().

The returned promise resolves to a list of the dropped indexes’ names as an array

Model.count()

Parameters
  • filter «Object»
  • [callback] «Function»
Returns:
  • «Query»

Counts number of documents that match filter in a database collection.

This method is deprecated. If you want to count the number of documents in a collection, e.g. count({}), use the instead. Otherwise, use the countDocuments() function instead.

Example:

  1. const count = await Adventure.count({ type: 'jungle' });
  2. console.log('there are %d jungle adventures', count);

Parameters
  • filter «Object»
  • [callback] «Function»
Returns:
  • «Query»

Counts number of documents matching filter in a database collection.

Example:

  1. Adventure.countDocuments({ type: 'jungle' }, function (err, count) {
  2.   console.log('there are %d jungle adventures', count);
  3. });

If you want to count all documents in a large collection, use the instead. If you call countDocuments({}), MongoDB will always execute a full collection scan and not use any indexes.

The countDocuments() function is similar to count(), but there are a few operators that countDocuments() does not support. Below are the operators that count() supports but countDocuments() does not, and the suggested replacement:

Parameters

  • docs «Array|Object» Documents to insert, as a spread or array

  • [options] «Object» Options passed down to save(). To specify options, docs must be an array, not a spread.

  • [callback] «Function» callback

Returns:
  • «Promise»

Shortcut for saving one or more documents to the database. MyModel.create(docs) does new MyModel(doc).save() for every doc in docs.

This function triggers the following middleware.

  • save()

Example:

  1. // Insert one new `Character` document
  2. await Character.create({ name: 'Jean-Luc Picard' });
  4. // Insert multiple new `Character` documents
  5. await Character.create([{ name: 'Will Riker' }, { name: 'Geordi LaForge' }]);
  7. // Create a new character within a transaction. Note that you **must**
  8. // pass an array as the first parameter to `create()` if you want to
  9. // specify options.
  10. await Character.create([{ name: 'Jean-Luc Picard' }], { session });

Model.createCollection()

Parameters

Create the collection for this model. By default, if no indexes are specified, mongoose will not create the collection for the model until any documents are created. Use this method to create the collection explicitly.

Note 1: You may need to call this before starting a transaction See

Note 2: You don’t have to call this if your schema contains index or unique field. In that case, just use Model.init()

Example:

  1. const userSchema = new Schema({ name: String })
  2. const User = mongoose.model('User', userSchema);
  4. User.createCollection().then(function(collection) {
  5.   console.log('Collection is created!');
  6. });

Model.createIndexes()

Parameters

  • [options] «Object» internal options

  • [cb] «Function» optional callback

Returns:
  • «Promise»

Similar to ensureIndexes(), except for it uses the function.

Parameters
  • conditions «Object»

  • [options] «Object» optional see

  • [callback] «Function»

Returns:
  • «Query»

Deletes all of the documents that match conditions from the collection. It returns an object with the property deletedCount containing the number of documents deleted. Behaves like remove(), but deletes all documents that match conditions regardless of the single option.

Example:

  1. await Character.deleteMany({ name: /Stark/, age: { $gte: 18 } }); // returns {deletedCount: x} where x is the number of documents deleted.

Note:

This function triggers deleteMany query hooks. Read the to learn more.

Parameters
  • conditions «Object»

  • [options] «Object» optional see

  • [callback] «Function»

Returns:
  • «Query»

Deletes the first document that matches conditions from the collection. It returns an object with the property deletedCount indicating how many documents were deleted. Behaves like remove(), but deletes at most one document regardless of the single option.

Example:

  1. await Character.deleteOne({ name: 'Eddard Stark' }); // returns {deletedCount: 1}

Note:

This function triggers deleteOne query hooks. Read the to learn more.

Parameters

  • options «Object» not used at all.

  • callback «Function» optional callback

Does a dry-run of Model.syncIndexes(), meaning that the result of this function would be the result of Model.syncIndexes().

Model.discriminator()

Parameters

  • name «String» discriminator model name

  • schema «Schema» discriminator model schema

  • [options] «Object|String» If string, same as options.value.

  • [options.value] «String» the string stored in the discriminatorKey property. If not specified, Mongoose uses the name parameter.

  • [options.clone=true] «Boolean» By default, discriminator() clones the given schema. Set to false to skip cloning.

Returns:
  • «Model» The newly created discriminator model

Adds a discriminator type.

Example:

  1. function BaseSchema() {
  2.   Schema.apply(this, arguments);
  4.   this.add({
  5.     name: String,
  6.     createdAt: Date
  7.   });
  8. }
  9. util.inherits(BaseSchema, Schema);
  11. const PersonSchema = new BaseSchema();
  12. const BossSchema = new BaseSchema({ department: String });
  14. const Person = mongoose.model('Person', PersonSchema);
  15. const Boss = Person.discriminator('Boss', BossSchema);
  16. new Boss().__t; // "Boss". `__t` is the default `discriminatorKey`
  18. const employeeSchema = new Schema({ boss: ObjectId });
  19. const Employee = Person.discriminator('Employee', employeeSchema, 'staff');
  20. new Employee().__t; // "staff" because of 3rd argument above

Parameters
  • field «String»

  • [conditions] «Object» optional

  • [callback] «Function»

Returns:
  • «Query»

Creates a Query for a distinct operation.

Passing a callback executes the query.

Example

  1. Link.distinct('url', { clicks: {$gt: 100}}, function (err, result) {
  2.   if (err) return handleError(err);
  4.   assert(Array.isArray(result));
  5.   console.log('unique urls with more than 100 clicks', result);
  6. })
  8. const query = Link.distinct('url');
  9. query.exec(callback);

Model.ensureIndexes()

Parameters

  • [options] «Object» internal options

  • [cb] «Function» optional callback

Returns:
  • «Promise»

Sends createIndex commands to mongo for each index declared in the schema. The createIndex commands are sent in series.

Example:

  1. Event.ensureIndexes(function (err) {
  2.   if (err) return handleError(err);
  3. });

After completion, an index event is emitted on this Model passing an error if one occurred.

Example:

  1. const eventSchema = new Schema({ thing: { type: 'string', unique: true }})
  2. const Event = mongoose.model('Event', eventSchema);
  4. Event.on('index', function (err) {
  5.   if (err) console.error(err); // error occurred during index creation
  6. })

NOTE: It is not recommended that you run this in production. Index creation may impact database performance depending on your load. Use with caution.

Model.estimatedDocumentCount()

Parameters
  • [options] «Object»
  • [callback] «Function»
Returns:
  • «Query»

Estimates the number of documents in the MongoDB collection. Faster than using countDocuments() for large collections because estimatedDocumentCount() uses collection metadata rather than scanning the entire collection.

Example:

  1. const numAdventures = Adventure.estimatedDocumentCount();

Type:
  • «property»

Event emitter that reports any errors that occurred. Useful for global error handling.

Example:

  1. MyModel.events.on('error', err => console.log(err.message));
  3. // Prints a 'CastError' because of the above handler
  4. await MyModel.findOne({ _id: 'notanid' }).catch(noop);

Parameters
  • filter «Object»

  • [options] «Object» optional see

  • [callback] «Function» callback

Returns:
  • «Query»

Returns true if at least one document exists in the database that matches the given filter, and false otherwise.

Under the hood, MyModel.exists({ answer: 42 }) is equivalent to MyModel.findOne({ answer: 42 }).select({ _id: 1 }).lean()

Example:

  1. await Character.deleteMany({});
  2. await Character.create({ name: 'Jean-Luc Picard' });
  4. await Character.exists({ name: /picard/i }); // { _id: ... }
  5. await Character.exists({ name: /riker/i }); // null

This function triggers the following middleware.

  • findOne()
Parameters
  • filter «Object|ObjectId»

  • [projection] «Object|String|Array<String>» optional fields to return, see

  • [options] «Object» optional see Query.prototype.setOptions()

  • [callback] «Function»

Returns:
  • «Query»

Finds documents.

Mongoose casts the filter to match the model’s schema before the command is sent. See our query casting tutorial for more information on how Mongoose casts filter.

Examples:

  1. // find all documents
  2. await MyModel.find({});
  4. // find all documents named john and at least 18
  5. await MyModel.find({ name: 'john', age: { $gte: 18 } }).exec();
  7. // executes, passing results to callback
  8. MyModel.find({ name: 'john', age: { $gte: 18 }}, function (err, docs) {});
  10. // executes, name LIKE john and only selecting the "name" and "friends" fields
  11. await MyModel.find({ name: /john/i }, 'name friends').exec();
  13. // passing options
  14. await MyModel.find({ name: /john/i }, null, { skip: 10 }).exec();

Parameters

  • [projection] «Object|String|Array<String>» optional fields to return, see

  • [options] «Object» optional see Query.prototype.setOptions()

  • [callback] «Function»

Returns:
  • «Query»

Finds a single document by its _id field. findById(id) is almost* equivalent to findOne({ _id: id }). If you want to query by a document’s _id, use findById() instead of findOne().

The id is cast based on the Schema before sending the command.

This function triggers the following middleware.

  • findOne()

* Except for how it treats undefined. If you use findOne(), you’ll see that findOne(undefined) and findOne({ _id: undefined }) are equivalent to findOne({}) and return arbitrary documents. However, mongoose translates findById(undefined) into findOne({ _id: null }).

Example:

  1. // Find the adventure with the given `id`, or `null` if not found
  2. await Adventure.findById(id).exec();
  4. // using callback
  5. Adventure.findById(id, function (err, adventure) {});
  7. // select only the adventures name and length
  8. await Adventure.findById(id, 'name length').exec();

Model.findByIdAndDelete()

Parameters

  • id «Object|Number|String» value of _id to query by

  • [options] «Object» optional see Query.prototype.setOptions()

  • [options.strict] «Boolean|String» overwrites the schema’s

  • [callback] «Function»

Returns:
  • «Query»

Issue a MongoDB findOneAndDelete() command by a document’s _id field. In other words, findByIdAndDelete(id) is a shorthand for .

This function triggers the following middleware.

  • findOneAndDelete()

Model.findByIdAndRemove()

Parameters

  • id «Object|Number|String» value of _id to query by

  • [options] «Object» optional see Query.prototype.setOptions()

  • [options.strict] «Boolean|String» overwrites the schema’s

  • [options.session=null] «ClientSession» The session associated with this query. See transactions docs.

  • [options.projection=null] «Object|String|Array<String>» optional fields to return, see

  • [callback] «Function»

Returns:
  • «Query»

Issue a mongodb findAndModify remove command by a document’s _id field. findByIdAndRemove(id, ...) is equivalent to findOneAndRemove({ _id: id }, ...).

Finds a matching document, removes it, passing the found document (if any) to the callback.

Executes the query if callback is passed.

This function triggers the following middleware.

  • findOneAndRemove()

Options:

  • sort: if multiple docs are found by the conditions, sets the sort order to choose which doc to update
  • select: sets the document fields to return
  • rawResult: if true, returns the raw result from the MongoDB driver
  • strict: overwrites the schema’s for this update

Examples:

  1. A.findByIdAndRemove(id, options, callback) // executes
  2. A.findByIdAndRemove(id, options)  // return Query
  3. A.findByIdAndRemove(id, callback) // executes
  4. A.findByIdAndRemove(id) // returns Query
  5. A.findByIdAndRemove()           // returns Query

Model.findByIdAndUpdate()

Parameters

  • id «Object|Number|String» value of _id to query by

  • [update] «Object»

  • [options] «Object» optional see Query.prototype.setOptions()

  • [options.returnDocument=’before’] «String» Has two possible values, 'before' and 'after'. By default, it will return the document before the update was applied.

  • [options.lean] «Object» if truthy, mongoose will return the document as a plain JavaScript object rather than a mongoose document. See and the Mongoose lean tutorial.

  • [options.session=null] «ClientSession» The session associated with this query. See .

  • [options.strict] «Boolean|String» overwrites the schema’s strict mode option

  • [options.timestamps=null] «Boolean» If set to false and are enabled, skip timestamps for this update. Note that this allows you to overwrite timestamps. Does nothing if schema-level timestamps are not set.

  • [options.overwrite=false] «Boolean» By default, if you don’t include any update operators in update, Mongoose will wrap update in $set for you. This prevents you from accidentally overwriting the document. This option tells Mongoose to skip adding $set. An alternative to this would be using .

  • [callback] «Function»

Returns:
  • «Query»

Issues a mongodb findAndModify update command by a document’s _id field. findByIdAndUpdate(id, ...) is equivalent to findOneAndUpdate({ _id: id }, ...).

Finds a matching document, updates it according to the update arg, passing any options, and returns the found document (if any) to the callback. The query executes if callback is passed.

This function triggers the following middleware.

  • findOneAndUpdate()

Options:

  • new: bool - true to return the modified document rather than the original. defaults to false
  • upsert: bool - creates the object if it doesn’t exist. defaults to false.
  • runValidators: if true, runs update validators on this command. Update validators validate the update operation against the model’s schema.
  • setDefaultsOnInsert: true by default. If setDefaultsOnInsert and upsert are true, mongoose will apply the specified in the model’s schema if a new document is created.
  • sort: if multiple docs are found by the conditions, sets the sort order to choose which doc to update
  • select: sets the document fields to return
  • rawResult: if true, returns the raw result from the MongoDB driver
  • strict: overwrites the schema’s for this update

Examples:

  1. A.findByIdAndUpdate(id, update, options, callback) // executes
  2. A.findByIdAndUpdate(id, update, options)  // returns Query
  3. A.findByIdAndUpdate(id, update, callback) // executes
  4. A.findByIdAndUpdate(id, update)           // returns Query
  5. A.findByIdAndUpdate()                     // returns Query

Note:

All top level update keys which are not atomic operation names are treated as set operations:

Example:

This helps prevent accidentally overwriting your document with { name: 'jason bourne' }.

Note:

findOneAndX and findByIdAndX functions support limited validation. You can enable validation by setting the runValidators option.

If you need full-fledged validation, use the traditional approach of first retrieving the document.

  1. Model.findById(id, function (err, doc) {
  2.   if (err) ..
  3.   doc.name = 'jason bourne';
  4.   doc.save(callback);
  5. });

Parameters
  • [conditions] «Object»

  • [projection] «Object|String|Array<String>» optional fields to return, see

  • [options] «Object» optional see Query.prototype.setOptions()

  • [callback] «Function»

Returns:
  • «Query»

Finds one document.

The conditions are cast to their respective SchemaTypes before the command is sent.

Note: conditions is optional, and if conditions is null or undefined, mongoose will send an empty findOne command to MongoDB, which will return an arbitrary document. If you’re querying by _id, use findById() instead.

Example:

  1. // Find one adventure whose `country` is 'Croatia', otherwise `null`
  2. await Adventure.findOne({ country: 'Croatia' }).exec();
  4. // using callback
  5. Adventure.findOne({ country: 'Croatia' }, function (err, adventure) {});
  7. // select only the adventures name and length
  8. await Adventure.findOne({ country: 'Croatia' }, 'name length').exec();

Model.findOneAndDelete()

Parameters
  • conditions «Object»

  • [options] «Object» optional see Query.prototype.setOptions()

  • [options.strict] «Boolean|String» overwrites the schema’s

  • [options.projection=null] «Object|String|Array<String>» optional fields to return, see Query.prototype.select()

  • [options.session=null] «ClientSession» The session associated with this query. See .

  • [callback] «Function»

Returns:
  • «Query»

Issue a MongoDB findOneAndDelete() command.

Finds a matching document, removes it, and passes the found document (if any) to the callback.

Executes the query if callback is passed.

This function triggers the following middleware.

  • findOneAndDelete()

This function differs slightly from Model.findOneAndRemove() in that findOneAndRemove() becomes a , as opposed to a findOneAndDelete() command. For most mongoose use cases, this distinction is purely pedantic. You should use findOneAndDelete() unless you have a good reason not to.

Options:

  • sort: if multiple docs are found by the conditions, sets the sort order to choose which doc to update
  • maxTimeMS: puts a time limit on the query - requires mongodb >= 2.6.0
  • select: sets the document fields to return, ex. { projection: { _id: 0 } }
  • projection: equivalent to select
  • rawResult: if true, returns the
  • strict: overwrites the schema’s strict mode option for this update

Examples:

  1. A.findOneAndDelete(conditions, options, callback) // executes
  2. A.findOneAndDelete(conditions, options)  // return Query
  3. A.findOneAndDelete(conditions, callback) // executes
  4. A.findOneAndDelete(conditions) // returns Query
  5. A.findOneAndDelete()           // returns Query

findOneAndX and findByIdAndX functions support limited validation. You can enable validation by setting the runValidators option.

If you need full-fledged validation, use the traditional approach of first retrieving the document.

  1. Model.findById(id, function (err, doc) {
  2.   if (err) ..
  3.   doc.name = 'jason bourne';
  4.   doc.save(callback);
  5. });

Parameters
  • conditions «Object»

  • [options] «Object» optional see

  • [options.session=null] «ClientSession» The session associated with this query. See transactions docs.

  • [options.strict] «Boolean|String» overwrites the schema’s

  • [options.projection=null] «Object|String|Array<String>» optional fields to return, see Query.prototype.select()

  • [callback] «Function»

Returns:
  • «Query»

Issue a mongodb findAndModify remove command.

Finds a matching document, removes it, passing the found document (if any) to the callback.

Executes the query if callback is passed.

This function triggers the following middleware.

  • findOneAndRemove()

Options:

  • sort: if multiple docs are found by the conditions, sets the sort order to choose which doc to update
  • maxTimeMS: puts a time limit on the query - requires mongodb >= 2.6.0
  • select: sets the document fields to return
  • projection: like select, it determines which fields to return, ex. { projection: { _id: 0 } }
  • rawResult: if true, returns the
  • strict: overwrites the schema’s strict mode option for this update

Examples:

  1. A.findOneAndRemove(conditions, options, callback) // executes
  2. A.findOneAndRemove(conditions, options)  // return Query
  3. A.findOneAndRemove(conditions, callback) // executes
  4. A.findOneAndRemove(conditions) // returns Query
  5. A.findOneAndRemove()           // returns Query

findOneAndX and findByIdAndX functions support limited validation. You can enable validation by setting the runValidators option.

If you need full-fledged validation, use the traditional approach of first retrieving the document.

  1. Model.findById(id, function (err, doc) {
  2.   if (err) ..
  3.   doc.name = 'jason bourne';
  4.   doc.save(callback);
  5. });

Parameters

  • filter «Object» Replace the first document that matches this filter

  • [replacement] «Object» Replace with this document

  • [options] «Object» optional see

  • [options.returnDocument=’before’] «String» Has two possible values, 'before' and 'after'. By default, it will return the document before the update was applied.

  • [options.lean] «Object» if truthy, mongoose will return the document as a plain JavaScript object rather than a mongoose document. See Query.lean() and .

  • [options.session=null] «ClientSession» The session associated with this query. See transactions docs.

  • [options.strict] «Boolean|String» overwrites the schema’s

  • [options.timestamps=null] «Boolean» If set to false and schema-level timestamps are enabled, skip timestamps for this update. Note that this allows you to overwrite timestamps. Does nothing if schema-level timestamps are not set.

  • [options.projection=null] «Object|String|Array<String>» optional fields to return, see

  • [callback] «Function»

Returns:
  • «Query»

Issue a MongoDB findOneAndReplace() command.

Finds a matching document, replaces it with the provided doc, and passes the returned doc to the callback.

Executes the query if callback is passed.

This function triggers the following query middleware.

  • findOneAndReplace()

Options:

  • sort: if multiple docs are found by the conditions, sets the sort order to choose which doc to update
  • maxTimeMS: puts a time limit on the query - requires mongodb >= 2.6.0
  • select: sets the document fields to return
  • projection: like select, it determines which fields to return, ex. { projection: { _id: 0 } }
  • rawResult: if true, returns the raw result from the MongoDB driver
  • strict: overwrites the schema’s for this update

Examples:

  1. A.findOneAndReplace(conditions, options, callback) // executes
  2. A.findOneAndReplace(conditions, options)  // return Query
  3. A.findOneAndReplace(conditions, callback) // executes
  4. A.findOneAndReplace()           // returns Query

Model.findOneAndUpdate()

Parameters
  • [conditions] «Object»
  • [update] «Object»

  • [options] «Object» optional see Query.prototype.setOptions()

  • [options.returnDocument=’before’] «String» Has two possible values, 'before' and 'after'. By default, it will return the document before the update was applied.

  • [options.lean] «Object» if truthy, mongoose will return the document as a plain JavaScript object rather than a mongoose document. See and the Mongoose lean tutorial.

  • [options.session=null] «ClientSession» The session associated with this query. See .

  • [options.strict] «Boolean|String» overwrites the schema’s strict mode option

  • [options.timestamps=null] «Boolean» If set to false and are enabled, skip timestamps for this update. Note that this allows you to overwrite timestamps. Does nothing if schema-level timestamps are not set.

  • [options.overwrite=false] «Boolean» By default, if you don’t include any update operators in update, Mongoose will wrap update in $set for you. This prevents you from accidentally overwriting the document. This option tells Mongoose to skip adding $set. An alternative to this would be using .

  • [options.upsert=false] «Boolean» if true, and no documents found, insert a new document

  • [options.projection=null] «Object|String|Array<String>» optional fields to return, see Query.prototype.select()

  • [callback] «Function»

Returns:
  • «Query»

Issues a mongodb findAndModify update command.

Finds a matching document, updates it according to the update arg, passing any options, and returns the found document (if any) to the callback. The query executes if callback is passed else a Query object is returned.

Options:

  • new: bool - if true, return the modified document rather than the original. defaults to false (changed in 4.0)
  • upsert: bool - creates the object if it doesn’t exist. defaults to false.
  • overwrite: bool - if true, replace the entire document.
  • fields: {Object|String} - Field selection. Equivalent to .select(fields).findOneAndUpdate()
  • maxTimeMS: puts a time limit on the query - requires mongodb >= 2.6.0
  • sort: if multiple docs are found by the conditions, sets the sort order to choose which doc to update
  • runValidators: if true, runs on this command. Update validators validate the update operation against the model’s schema.
  • setDefaultsOnInsert: true by default. If setDefaultsOnInsert and upsert are true, mongoose will apply the defaults specified in the model’s schema if a new document is created.
  • rawResult: if true, returns the
  • strict: overwrites the schema’s strict mode option for this update

Examples:

  1. A.findOneAndUpdate(conditions, update, options, callback) // executes
  2. A.findOneAndUpdate(conditions, update, options)  // returns Query
  3. A.findOneAndUpdate(conditions, update, callback) // executes
  4. A.findOneAndUpdate(conditions, update)           // returns Query
  5. A.findOneAndUpdate()                             // returns Query

Note:

All top level update keys which are not atomic operation names are treated as set operations:

Example:

  1. const query = { name: 'borne' };
  2. Model.findOneAndUpdate(query, { name: 'jason bourne' }, options, callback)
  4. // is sent as
  5. Model.findOneAndUpdate(query, { $set: { name: 'jason bourne' }}, options, callback)

This helps prevent accidentally overwriting your document with { name: 'jason bourne' }.

Note:

findOneAndX and findByIdAndX functions support limited validation that you can enable by setting the runValidators option.

If you need full-fledged validation, use the traditional approach of first retrieving the document.

  1. const doc = await Model.findById(id);
  2. doc.name = 'jason bourne';
  3. await doc.save();

Model.hydrate()

Parameters
  • obj «Object»
  • [projection] «Object|String|Array<String>» optional projection containing which fields should be selected for this document
Returns:
  • «Document» document instance

Shortcut for creating a new Document from existing raw data, pre-saved in the DB. The document returned has no paths marked as modified initially.

Example:

  1. // hydrate previous data into a Mongoose document
  2. const mongooseCandy = Candy.hydrate({ _id: '54108337212ffb6d459f854c', type: 'jelly bean' });

Parameters
  • [callback] «Function»

This function is responsible for building , unless autoIndex is turned off.

Mongoose calls this function automatically when a model is created using or connection.model(), so you don’t need to call it. This function is also idempotent, so you may call it to get back a promise that will resolve when your indexes are finished building as an alternative to

Example:

  1. const eventSchema = new Schema({ thing: { type: 'string', unique: true }})
  2. // This calls `Event.init()` implicitly, so you don't need to call
  3. // `Event.init()` on your own.
  4. const Event = mongoose.model('Event', eventSchema);
  6. Event.init().then(function(Event) {
  7.   // You can also use `Event.on('index')` if you prefer event emitters
  8.   // over promises.
  9.   console.log('Indexes are done building!');
  10. });

Model.insertMany()

Parameters
  • doc(s) «Array|Object|*»

  • [options] «Object» see the mongodb driver options

  • [options.ordered «Boolean» = true] if true, will fail fast on the first error encountered. If false, will insert all the documents it can and report errors later. An insertMany() with ordered = false is called an “unordered” insertMany().

  • [options.rawResult «Boolean» = false] if false, the returned promise resolves to the documents that passed mongoose document validation. If true, will return the with a mongoose property that contains validationErrors if this is an unordered insertMany.

  • [options.lean «Boolean» = false] if true, skips hydrating and validating the documents. This option is useful if you need the extra performance, but Mongoose won’t validate the documents before inserting.

  • [options.limit «Number» = null] this limits the number of documents being processed (validation/casting) by mongoose in parallel, this does NOT send the documents in batches to MongoDB. Use this option if you’re processing a large number of documents and your app is running out of memory.

  • [options.populate «String|Object|Array» = null] populates the result documents. This option is a no-op if rawResult is set.

  • [callback] «Function» callback

Returns:
  • «Promise» resolving to the raw result from the MongoDB driver if options.rawResult was true, or the documents that passed validation, otherwise

Shortcut for validating an array of documents and inserting them into MongoDB if they’re all valid. This function is faster than .create() because it only sends one operation to the server, rather than one for each document.

Mongoose always validates each document before sending insertMany to MongoDB. So if one document has a validation error, no documents will be saved, unless you set .

This function does not trigger save middleware.

This function triggers the following middleware.

  • insertMany()

Example:

  1. const arr = [{ name: 'Star Wars' }, { name: 'The Empire Strikes Back' }];
  2. Movies.insertMany(arr, function(error, docs) {});

Model.inspect()

Helper for console.log. Given a model named ‘MyModel’, returns the string 'Model { MyModel }'.

Example:

  1. const MyModel = mongoose.model('Test', Schema({ name: String }));
  2. MyModel.inspect(); // 'Model { Test }'
  3. console.log(MyModel); // Prints 'Model { Test }'

Parameters
  • [cb] «Function» optional callback
Returns:
  • «Promise,undefined» Returns undefined if callback is specified, returns a promise if no callback.

Lists the indexes currently defined in MongoDB. This may or may not be the same as the indexes defined in your schema depending on whether you use the autoIndex option and if you build indexes manually.

Model.mapReduce()

Parameters

  • o «Object» an object specifying map-reduce options

  • [callback] «Function» optional callback

Returns:
  • «Promise»

Executes a mapReduce command.

This function does not trigger any middleware.

Example:

  1. const o = {};
  2. // `map()` and `reduce()` are run on the MongoDB server, not Node.js,
  3. // these functions are converted to strings
  4. o.map = function () { emit(this.name, 1) };
  5. o.reduce = function (k, vals) { return vals.length };
  6. User.mapReduce(o, function (err, results) {
  7.   console.log(results)
  8. })

Other options:

  • query {Object} query filter object.
  • sort {Object} sort input objects using this key
  • limit {Number} max number of documents
  • keeptemp {Boolean, default:false} keep temporary data
  • finalize {Function} finalize function
  • scope {Object} scope variables exposed to map/reduce/finalize during execution
  • jsMode {Boolean, default:false} it is possible to make the execution stay in JS. Provided in MongoDB > 2.0.X
  • verbose {Boolean, default:false} provide statistics on job execution time.
  • readPreference {String}
  • out* {Object, default: {inline:1}} sets the output target for the map reduce job.

* out options:

  • {inline:1} the results are returned in an array
  • {replace: 'collectionName'} add the results to collectionName: the results replace the collection
  • {reduce: 'collectionName'} add the results to collectionName: if dups are detected, uses the reducer / finalize functions
  • {merge: 'collectionName'} add the results to collectionName: if dups exist the new docs overwrite the old

If options.out is set to replace, merge, or reduce, a Model instance is returned that can be used for further querying. Queries run against this model are all executed with the lean option; meaning only the js object is returned and no Mongoose magic is applied (getters, setters, etc).

Example:

  1. const o = {};
  2. // You can also define `map()` and `reduce()` as strings if your
  3. // linter complains about `emit()` not being defined
  5. o.reduce = 'function (k, vals) { return vals.length }';
  6. o.out = { replace: 'createdCollectionNameForResults' }
  7. o.verbose = true;
  9. User.mapReduce(o, function (err, model, stats) {
  10.   console.log('map reduce took %d ms', stats.processtime)
  11.   model.find().where('value').gt(10).exec(function (err, docs) {
  12.     console.log(docs);
  13.   });
  14. })
  16. // `mapReduce()` returns a promise. However, ES6 promises can only
  17. // resolve to exactly one value,
  18. o.resolveToObject = true;
  19. const promise = User.mapReduce(o);
  20. promise.then(function (res) {
  21.   const model = res.model;
  22.   const stats = res.stats;
  23.   console.log('map reduce took %d ms', stats.processtime)
  24.   return model.find().where('value').gt(10).exec();
  25. }).then(function (docs) {
  26.    console.log(docs);
  27. }).then(null, handleError).end()

Parameters

  • docs «Document|Array» Either a single document or array of documents to populate.

  • options «Object|String» Either the paths to populate or an object specifying all parameters

  • [options.path=null] «string» The path to populate.

  • [options.retainNullValues=false] «boolean» By default, Mongoose removes null and undefined values from populated arrays. Use this option to make populate() retain null and undefined array entries.

  • [options.getters=false] «boolean» If true, Mongoose will call any getters defined on the localField. By default, Mongoose gets the raw value of localField. For example, you would need to set this option to true if you wanted to .

  • [options.clone=false] «boolean» When you do BlogPost.find().populate('author'), blog posts with the same author will share 1 copy of an author doc. Enable this option to make Mongoose clone populated docs before assigning them.

  • [options.match=null] «Object|Function» Add an additional filter to the populate query. Can be a filter object containing MongoDB query syntax, or a function that returns a filter object.

  • [options.skipInvalidIds=false] «Boolean» By default, Mongoose throws a cast error if localField and foreignField schemas don’t line up. If you enable this option, Mongoose will instead filter out any localField properties that cannot be casted to foreignField‘s schema type.

  • [options.perDocumentLimit=null] «Number» For legacy reasons, limit with populate() may give incorrect results because it only executes a single query for every document being populated. If you set perDocumentLimit, Mongoose will ensure correct limit per document by executing a separate query for each document to populate(). For example, .find().populate({ path: 'test', perDocumentLimit: 2 }) will execute 2 additional queries if .find() returns 2 documents.

  • [options.strictPopulate=true] «Boolean» Set to false to allow populating paths that aren’t defined in the given model’s schema.

  • [options.options=null] «Object» Additional options like limit and lean.

  • [options.transform=null] «Function» Function that Mongoose will call on every populated document that allows you to transform the populated document.

  • [callback(err,doc)] «Function» Optional callback, executed upon completion. Receives err and the doc(s).

Returns:
  • «Promise»

Populates document references.

Changed in Mongoose 6: the model you call populate() on should be the “local field” model, not the “foreign field” model.

Available top-level options:

  • path: space delimited path(s) to populate
  • select: optional fields to select
  • match: optional query conditions to match
  • model: optional name of the model to use for population
  • options: optional query options like sort, limit, etc
  • justOne: optional boolean, if true Mongoose will always set path to an array. Inferred from schema by default.
  • strictPopulate: optional boolean, set to false to allow populating paths that aren’t in the schema.

Examples:

  1. const Dog = mongoose.model('Dog', new Schema({ name: String, breed: String }));
  2. const Person = mongoose.model('Person', new Schema({
  3.   name: String,
  4.   pet: { type: mongoose.ObjectId, ref: 'Dog' }
  5. }));
  7. const pets = await Pet.create([
  8.   { name: 'Daisy', breed: 'Beagle' },
  9.   { name: 'Einstein', breed: 'Catalan Sheepdog' }
  10. ]);
  12. // populate many plain objects
  13. const users = [
  14.   { name: 'John Wick', dog: pets[0]._id },
  15.   { name: 'Doc Brown', dog: pets[1]._id }
  16. ];
  17. await User.populate(users, { path: 'dog', select: 'name' });
  18. users[0].dog.name; // 'Daisy'
  19. users[0].dog.breed; // undefined because of `select`

Type:
  • «property»

Additional properties to attach to the query when calling save() and isNew is false.

Model.prototype.$where()

Parameters
  • argument «String|Function» is a javascript string or anonymous function
Returns:
  • «Query»

Creates a Query and specifies a $where condition.

Sometimes you need to query for things in mongodb using a JavaScript expression. You can do so via find({ $where: javascript }), or you can use the mongoose shortcut method $where via a Query chain or from your mongoose Model.

  1. Blog.$where('this.username.indexOf("val") !== -1').exec(function (err, docs) {});

Model.prototype.base

Type:
  • «property»

Base Mongoose instance the model uses.

Type:
  • «property»

If this is a discriminator model, baseModelName is the name of the base model.

Model.prototype.collection

Type:
  • «property»

Collection the model uses.

This property is read-only. Modifying this property is a no-op.

Type:
  • «property»

Connection the model uses.

Model.prototype.deleteOne()

Parameters
  • [fn] «function(err|product)» optional callback
Returns:
  • «Promise» Promise

Removes this document from the db. Equivalent to .remove().

Example:

  1. product = await product.deleteOne();
  2. await Product.findById(product._id); // null

Type:
  • «property»

Registered discriminators for this model.

Model.prototype.model()

Parameters
  • name «String» model name

Returns another Model instance.

Example:

Model.prototype.modelName

Type:
  • «property»

The name of the model

Parameters

  • [options] «Object»

  • [options.session=null] «Session» the associated with this operation. If not specified, defaults to the document’s associated session.

  • [fn] «function(err|product)» optional callback

Returns:
  • «Promise» Promise

Removes this document from the db.

Example:

  1. product.remove(function (err, product) {
  2.   if (err) return handleError(err);
  3.   Product.findById(product._id, function (err, product) {
  4.     console.log(product) // null
  5.   })
  6. })

As an extra measure of flow control, remove will return a Promise (bound to fn if passed) so it could be chained, or hooked to recieve errors

Example:

  1. product.remove().then(function (product) {
  2.    ...
  3. }).catch(function (err) {
  4.    assert.ok(err)
  5. })

Parameters

  • [options] «Object» options optional options

  • [options.session=null] «Session» the associated with this save operation. If not specified, defaults to the document’s associated session.

  • [options.safe] «Object» (DEPRECATED) overrides . Use the w option instead.

  • [options.validateBeforeSave] «Boolean» set to false to save without validating.

  • [options.validateModifiedOnly=false] «Boolean» if true, Mongoose will only validate modified paths, as opposed to modified paths and required paths.

  • [options.w] «Number|String» set the write concern. Overrides the

  • [options.j] «Boolean» set to true for MongoDB to wait until this save() has been journaled before resolving the returned promise. Overrides the

  • [options.wtimeout] «Number» sets a timeout for the write concern. Overrides the .

  • [options.checkKeys=true] «Boolean» the MongoDB driver prevents you from saving keys that start with ‘$’ or contain ‘.’ by default. Set this option to false to skip that check. See restrictions on field names

  • [options.timestamps=true] «Boolean» if false and are enabled, skip timestamps for this save().

  • [fn] «Function» optional callback

Returns:
  • «Promise,undefined» Returns undefined if used with callback or a Promise otherwise.

Saves this document by inserting a new document into the database if is true, or sends an updateOne operation with just the modified paths if isNew is false.

Example:

  1. product.sold = Date.now();
  2. product = await product.save();

If save is successful, the returned promise will fulfill with the document saved.

Example:

  1. const newProduct = await product.save();
  2. newProduct === product; // true

Model.prototype.schema

Type:
  • «property»

Schema the model uses.

Parameters
  • conditions «Object»

  • [options] «Object»

  • [options.session=null] «Session» the associated with this operation.

  • [callback] «Function»

Returns:
  • «Query»

Removes all documents that match conditions from the collection. To remove just the first document that matches conditions, set the single option to true.

This method is deprecated. See for details.

Example:

  1. const res = await Character.remove({ name: 'Eddard Stark' });
  2. res.deletedCount; // Number of documents removed

Note:

This method sends a remove command directly to MongoDB, no Mongoose documents are involved. Because no Mongoose documents are involved, Mongoose does not execute document middleware.

Model.replaceOne()

Parameters
  • filter «Object»
  • doc «Object»

  • [options] «Object» optional see Query.prototype.setOptions()

  • [options.strict] «Boolean|String» overwrites the schema’s

  • [options.upsert=false] «Boolean» if true, and no documents found, insert a new document

  • [options.writeConcern=null] «Object» sets the write concern for replica sets. Overrides the

  • [options.timestamps=null] «Boolean» If set to false and schema-level timestamps are enabled, skip timestamps for this update. Does nothing if schema-level timestamps are not set.

  • [callback] «Function» function(error, res) {} where res has 3 properties: n, nModified, ok.

Returns:
  • «Query»

Same as update(), except MongoDB replace the existing document with the given document (no atomic operators like $set).

Example:

  1. const res = await Person.replaceOne({ _id: 24601 }, { name: 'Jean Valjean' });
  2. res.matchedCount; // Number of documents matched
  3. res.modifiedCount; // Number of documents modified
  4. res.acknowledged; // Boolean indicating everything went smoothly.
  5. res.upsertedId; // null or an id containing a document that had to be upserted.
  6. res.upsertedCount; // Number indicating how many documents had to be upserted. Will either be 0 or 1.

This function triggers the following middleware.

  • replaceOne()

Model.startSession()

Parameters

  • [options] «Object» see the mongodb driver options

  • [options.causalConsistency=true] «Boolean» set to false to disable causal consistency

  • [callback] «Function»

Returns:
  • «Promise<ClientSession>» promise that resolves to a MongoDB driver ClientSession

Requires MongoDB >= 3.6.0. Starts a MongoDB session for benefits like causal consistency, , and transactions.

Calling MyModel.startSession() is equivalent to calling MyModel.db.startSession().

This function does not trigger any middleware.

Example:

  1. const session = await Person.startSession();
  2. let doc = await Person.findOne({ name: 'Ned Stark' }, null, { session });
  3. await doc.remove();
  4. // `doc` will always be null, even if reading from a replica set
  5. // secondary. Without causal consistency, it is possible to
  6. // get a doc back from the below query if the query reads from a
  7. // secondary that is experiencing replication lag.
  8. doc = await Person.findOne({ name: 'Ned Stark' }, null, { session, readPreference: 'secondary' });

Parameters

  • [options] «Object» options to pass to ensureIndexes()

  • [options.background=null] «Boolean» if specified, overrides each index’s background property

  • [callback] «Function» optional callback

Returns:
  • «Promise,undefined» Returns undefined if callback is specified, returns a promise if no callback.

Makes the indexes in MongoDB match the indexes defined in this model’s schema. This function will drop any indexes that are not defined in the model’s schema except the _id index, and build any indexes that are in your schema but not in MongoDB.

See the introductory blog post for more information.

Example:

  1. const schema = new Schema({ name: { type: String, unique: true } });
  2. const Customer = mongoose.model('Customer', schema);
  3. await Customer.collection.createIndex({ age: 1 }); // Index is not in schema
  4. // Will drop the 'age' index and create an index on `name`
  5. await Customer.syncIndexes();

Parameters
  • raw «Object» fields/conditions that may contain aliased keys
Returns:
  • «Object» the translated ‘pure’ fields/conditions

Translate any aliases fields/conditions so the final query or document object is pure

Example:

  1. Character
  2.   .find(Character.translateAliases({
  3.     '名': 'Eddard Stark' // Alias for 'name'
  4.   })
  5.   .exec(function(err, characters) {})

Note:

Only translate arguments of object type anything else is returned raw

Parameters
  • filter «Object»
  • doc «Object»

  • [options] «Object» optional see

  • [options.strict] «Boolean|String» overwrites the schema’s strict mode option

  • [options.upsert=false] «Boolean» if true, and no documents found, insert a new document

  • [options.writeConcern=null] «Object» sets the for replica sets. Overrides the schema-level write concern

  • [options.multi=false] «Boolean» whether multiple documents should be updated or just the first one that matches filter.

  • [options.runValidators=false] «Boolean» if true, runs on this command. Update validators validate the update operation against the model’s schema.

  • [options.setDefaultsOnInsert=false] «Boolean» true by default. If setDefaultsOnInsert and upsert are true, mongoose will apply the defaults specified in the model’s schema if a new document is created.

  • [options.timestamps=null] «Boolean» If set to false and are enabled, skip timestamps for this update. Does nothing if schema-level timestamps are not set.

  • [options.overwrite=false] «Boolean» By default, if you don’t include any update operators in doc, Mongoose will wrap doc in $set for you. This prevents you from accidentally overwriting the document. This option tells Mongoose to skip adding $set.

  • [callback] «Function» params are (error, )

  • [callback] «Function»

Returns:
  • «Query»

Updates one document in the database without returning it.

This function triggers the following middleware.

  • update()

This method is deprecated. See for details.

Examples:

  1. MyModel.update({ age: { $gt: 18 } }, { oldEnough: true }, fn);
  3. const res = await MyModel.update({ name: 'Tobi' }, { ferret: true });
  4. res.n; // Number of documents that matched `{ name: 'Tobi' }`
  5. // Number of documents that were changed. If every doc matched already
  6. // had `ferret` set to `true`, `nModified` will be 0.
  7. res.nModified;

Valid options:

  • strict (boolean): overrides the schema-level strict option for this update
  • upsert (boolean): whether to create the doc if it doesn’t match (false)
  • writeConcern (object): sets the for replica sets. Overrides the schema-level write concern
  • multi (boolean): whether multiple documents should be updated (false)
  • runValidators: if true, runs on this command. Update validators validate the update operation against the model’s schema.
  • setDefaultsOnInsert (boolean): if this and upsert are true, mongoose will apply the defaults specified in the model’s schema if a new document is created. This option only works on MongoDB >= 2.4 because it relies on .
  • timestamps (boolean): If set to false and schema-level timestamps are enabled, skip timestamps for this update. Does nothing if schema-level timestamps are not set.
  • overwrite (boolean): disables update-only mode, allowing you to overwrite the doc (false)

All update values are cast to their appropriate SchemaTypes before being sent.

The callback function receives (err, rawResponse).

  • err is the error if any occurred
  • rawResponse is the full response from Mongo

Note:

All top level keys which are not atomic operation names are treated as set operations:

Example:

  1. const query = { name: 'borne' };
  2. Model.update(query, { name: 'jason bourne' }, options, callback);
  4. // is sent as
  5. Model.update(query, { $set: { name: 'jason bourne' }}, options, function(err, res));
  6. // if overwrite option is false. If overwrite is true, sent without the $set wrapper.

This helps prevent accidentally overwriting all documents in your collection with { name: 'jason bourne' }.

Note:

Be careful to not use an existing model instance for the update clause (this won’t work and can cause weird behavior like infinite loops). Also, ensure that the update clause does not have an _id property, which causes Mongo to return a “Mod on _id not allowed” error.

Parameters
  • filter «Object»
  • update «Object|Array»

  • [options] «Object» optional see

  • [options.strict] «Boolean|String» overwrites the schema’s strict mode option

  • [options.upsert=false] «Boolean» if true, and no documents found, insert a new document

  • [options.writeConcern=null] «Object» sets the for replica sets. Overrides the schema-level write concern

  • [options.timestamps=null] «Boolean» If set to false and are enabled, skip timestamps for this update. Does nothing if schema-level timestamps are not set.

  • [callback] «Function» function(error, res) {} where res has 5 properties: modifiedCount, matchedCount, acknowledged, upsertedId, and upsertedCount.

Returns:
  • «Query»

Same as update(), except MongoDB will update all documents that match filter (as opposed to just the first one) regardless of the value of the multi option.

Note updateMany will not fire update middleware. Use pre('updateMany') and post('updateMany') instead.

Example:

  1. const res = await Person.updateMany({ name: /Stark$/ }, { isDeleted: true });
  2. res.matchedCount; // Number of documents matched
  3. res.modifiedCount; // Number of documents modified
  4. res.acknowledged; // Boolean indicating everything went smoothly.
  5. res.upsertedId; // null or an id containing a document that had to be upserted.
  6. res.upsertedCount; // Number indicating how many documents had to be upserted. Will either be 0 or 1.

This function triggers the following middleware.

  • updateMany()

Parameters
  • filter «Object»
  • update «Object|Array»

  • [options] «Object» optional see

  • [options.strict] «Boolean|String» overwrites the schema’s strict mode option

  • [options.upsert=false] «Boolean» if true, and no documents found, insert a new document

  • [options.writeConcern=null] «Object» sets the for replica sets. Overrides the schema-level write concern

  • [options.timestamps=null] «Boolean» If set to false and are enabled, skip timestamps for this update. Note that this allows you to overwrite timestamps. Does nothing if schema-level timestamps are not set.

  • [callback] «Function» params are (error, writeOpResult)

Returns:
  • «Query»

Same as update(), except it does not support the multi or overwrite options.

  • MongoDB will update only the first document that matches filter regardless of the value of the multi option.
  • Use replaceOne() if you want to overwrite an entire document rather than using atomic operators like $set.

Example:

  1. const res = await Person.updateOne({ name: 'Jean-Luc Picard' }, { ship: 'USS Enterprise' });
  2. res.matchedCount; // Number of documents matched
  3. res.modifiedCount; // Number of documents modified
  4. res.acknowledged; // Boolean indicating everything went smoothly.
  5. res.upsertedId; // null or an id containing a document that had to be upserted.
  6. res.upsertedCount; // Number indicating how many documents had to be upserted. Will either be 0 or 1.

This function triggers the following middleware.

  • updateOne()

Parameters
  • obj «Object»
  • pathsToValidate «Array»
  • [context] «Object»
  • [callback] «Function»
Returns:
  • «Promise,undefined»

Casts and validates the given object against this model’s schema, passing the given context to custom validators.

Example:

  1. const Model = mongoose.model('Test', Schema({
  2.   name: { type: String, required: true },
  3.   age: { type: Number, required: true }
  4. });
  6. try {
  7.   await Model.validate({ name: null }, ['name'])
  8. } catch (err) {
  9.   err instanceof mongoose.Error.ValidationError; // true
  10.   Object.keys(err.errors); // ['name']
  11. }

Model.watch()

Parameters
Returns:
  • «ChangeStream» mongoose-specific change stream wrapper, inherits from EventEmitter

Requires a replica set running MongoDB >= 3.6.0. Watches the underlying collection for changes using MongoDB change streams.

This function does not trigger any middleware. In particular, it does not trigger aggregate middleware.

  • ‘change’: A change occurred, see below example
  • ‘error’: An unrecoverable error occurred. In particular, change streams currently error out if they lose connection to the replica set primary. Follow for updates.
  • ‘end’: Emitted if the underlying stream is closed
  • ‘close’: Emitted if the underlying stream is closed

Example:

  1. const doc = await Person.create({ name: 'Ned Stark' });
  2. const changeStream = Person.watch().on('change', change => console.log(change));
  3. // Will print from the above `console.log()`:
  4. // { _id: { _data: ... },
  5. //   operationType: 'delete',
  6. //   ns: { db: 'mydb', coll: 'Person' },
  7. //   documentKey: { _id: 5a51b125c5500f5aa094c7bd } }
  8. await doc.remove();
Parameters
  • path «String»
  • [val] «Object» optional value
Returns:
  • «Query»

Creates a Query, applies the passed conditions, and returns the Query.

For example, instead of writing:

  1. User.find({age: {$gte: 21, $lte: 65}}, callback);

we can instead write:

  1. User.where('age').gte(21).lte(65).exec(callback);

Since the Query class also supports where you can continue chaining

  1. User
  2. .where('age').gte(21).lte(65)
  3. .where('name', /^b/i)
  4. ... etc

increment()

Example:

  1. Model.findById(id, function (err, doc) {
  2.   doc.increment();
  3.   doc.save(function (err) { .. })
  4. })