Class: Mongo::Collection

Relationships & Source Files
Namespace Children
Modules: `Helpers`, `QueryableEncryption`
Classes: `View`
Super Chains via Extension / Inclusion / Inheritance
Class Chain: self, Forwardable
Instance Chain: self, `Helpers`, `QueryableEncryption`, `Retryable`
Inherits:	Object
Defined in:	lib/mongo/collection.rb, lib/mongo/collection/helpers.rb, lib/mongo/collection/queryable_encryption.rb, lib/mongo/collection/view.rb, lib/mongo/collection/view/aggregation.rb, lib/mongo/collection/view/change_stream.rb, lib/mongo/collection/view/explainable.rb, lib/mongo/collection/view/immutable.rb, lib/mongo/collection/view/iterable.rb, lib/mongo/collection/view/map_reduce.rb, lib/mongo/collection/view/readable.rb, lib/mongo/collection/view/writable.rb, lib/mongo/collection/view/builder/aggregation.rb, lib/mongo/collection/view/builder/map_reduce.rb, lib/mongo/collection/view/change_stream/retryable.rb

Overview

Represents a collection in the database and operations that can directly be applied to one.

Since:

2.0.0

Constant Summary

CAPPED =

The capped option.
Since:
- 2.1.0
# File 'lib/mongo/collection.rb', line 38
```
'capped'.freeze
```
CHANGEABLE_OPTIONS =

Options that can be updated on a new Collection instance via the #with method.
Since:
- 2.1.0
# File 'lib/mongo/collection.rb', line 63
```
[ :read, :read_concern, :write, :write_concern ].freeze
```

CREATE_COLLECTION_OPTIONS = Internal use only

Options map to transform create collection options.

Since:

2.0.0

# File 'lib/mongo/collection.rb', line 68

{
  :time_series => :timeseries,
  :expire_after => :expireAfterSeconds,
  :clustered_index => :clusteredIndex,
  :change_stream_pre_and_post_images => :changeStreamPreAndPostImages,
  :encrypted_fields => :encryptedFields,
  :validator => :validator,
  :view_on => :viewOn
}

NS =

The ns field constant.
Since:
- 2.1.0
# File 'lib/mongo/collection.rb', line 43
```
'ns'.freeze
```

`QueryableEncryption` - Included

QE2_MIN_WIRE_VERSION

Class Method Summary

.new(database, name, options = {}) ⇒ Collection constructor

Instantiate a new collection.

Instance Attribute Summary

#capped? ⇒ true | false readonly

Is the collection capped?
#database ⇒ Mongo::Database readonly
#name ⇒ String readonly
#options ⇒ Hash readonly
#system_collection? ⇒ Boolean readonly Internal use only Internal use only

Whether the collection is a system collection.

Instance Method Summary

#==(other) ⇒ true | false

Check if a collection is equal to another object.
#aggregate(pipeline, options = {}) ⇒ View::Aggregation

Perform an aggregation on the collection.
#bulk_write(requests, options = {}) ⇒ BulkWrite::Result

Execute a batch of bulk write operations.
#count(filter = nil, options = {}) ⇒ Integer deprecated
Deprecated.
Use #count_documents or estimated_document_count instead. However, note that the following operators will need to be substituted when switching to #count_documents:
```
* $where should be replaced with $expr (only works on 3.6+)
* $near should be replaced with $geoWithin with $center
* $nearSphere should be replaced with $geoWithin with $centerSphere
```
#count_documents(filter = {}, options = {}) ⇒ Integer

Gets the number of documents matching the query.
#create(opts = {}) ⇒ Result

Force the collection to be created in the database.
#delete_many(filter = nil, options = {}) ⇒ Result

Remove documents from the collection.
#delete_one(filter = nil, options = {}) ⇒ Result

Remove a document from the collection.
#distinct(field_name, filter = nil, options = {}) ⇒ Array<Object>

Get a list of distinct values for a specific field.
#drop(opts = {}) ⇒ Result

Drop the collection.
#estimated_document_count(options = {}) ⇒ Integer

Gets an estimate of the number of documents in the collection using the collection metadata.
#find(filter = nil, options = {}) ⇒ CollectionView

Find documents in the collection.
#find_one_and_delete(filter, options = {}) ⇒ BSON::Document^?

Finds a single document in the database via findAndModify and deletes it, returning the original document.
#find_one_and_replace(filter, replacement, options = {}) ⇒ BSON::Document

Finds a single document and replaces it, returning the original doc unless otherwise specified.
#find_one_and_update(filter, update, options = {}) ⇒ BSON::Document

Finds a single document via findAndModify and updates it, returning the original doc unless otherwise specified.
#indexes(options = {}) ⇒ Index::View

Get a view of all indexes for this collection.
#insert_many(documents, options = {}) ⇒ Result

Insert the provided documents into the collection.
#insert_one(document, opts = {}) ⇒ Result

Insert a single document into the collection.
#inspect ⇒ String

Get a pretty printed string inspection for the collection.
#namespace ⇒ String

Get the fully qualified namespace of the collection.
#parallel_scan(cursor_count, options = {}) ⇒ Array<Cursor>

Execute a parallel scan on the collection view.
#read_concern ⇒ Hash

Get the effective read concern for this collection instance.
#read_preference ⇒ Hash

Get the effective read preference for this collection.
#replace_one(filter, replacement, options = {}) ⇒ Result

Replaces a single document in the collection with the new document.
#search_indexes(options = {}) ⇒ SearchIndex::View

Get a view of all search indexes for this collection.
#server_selector ⇒ Mongo::ServerSelector

Get the server selector for this collection.
#update_many(filter, update, options = {}) ⇒ Result

Update documents in the collection.
#update_one(filter, update, options = {}) ⇒ Result

Update a single document in the collection.
#watch(pipeline = [], options = {}) ⇒ ChangeStream

As of version 3.6 of the MongoDB server, a “$changeStream“ pipeline stage is supported in the aggregation framework.
#with(new_options) ⇒ Mongo::Collection
#write_concern ⇒ Mongo::WriteConcern

Get the effective write concern on this collection.
#write_concern_with_session(session) ⇒ Mongo::WriteConcern Internal use only Internal use only

Get the write concern to use for an operation on this collection, given a session.

`Helpers` - Included

#do_drop

Executes drop operation and and ignores NamespaceNotFound error.

`QueryableEncryption` - Included

#maybe_create_qe_collections	Creates auxiliary collections and indices for queryable encryption if necessary.
#maybe_drop_emm_collections	Drops auxiliary collections and indices for queryable encryption if necessary.
#check_wire_version!	Creating encrypted collections is only supported on 7.0.0 and later (wire version 21+).
#create_operation_for	Returns a new create operation for the given collection.
#emm_collections	Checks if names for auxiliary collections are set and returns them, otherwise returns default names.
#encrypted_fields_for_drop_from_map	Tries to return the encrypted fields from the `{encrypted_fields_map`} value, for the current namespace.
#encrypted_fields_from	Tries to return the encrypted fields from the argument.

`Retryable` - Included

#read_worker	Returns the read worker for handling retryable reads.
#select_server	This is a separate method to make it possible for the test suite to assert that server selection is performed during retry attempts.
#write_worker	Returns the write worker for handling retryable writes.

Constructor Details

.new(database, name, options = {}) ⇒ `Collection`

Instantiate a new collection.

Examples:

Instantiate a new collection.

Mongo::Collection.new(database, 'test')

Parameters:

database (Mongo::Database) —

The collection’s database.
name (String, Symbol) —

The collection name.
options (Hash) (defaults to: {}) —

The collection options.
opts (Hash) —

a customizable set of options

Options Hash (options):

:read_concern (Hash) —
The read concern options hash, with the following optional keys:
- :level – the read preference level as a symbol; valid values
```
are *:local*, *:majority*, and *:snapshot*
```
:read (Hash) —
The read preference options. The hash may have the following items:
- :mode – read preference specified as a symbol; valid values are :primary, :primary_preferred, :secondary, :secondary_preferred and :nearest.
- :tag_sets – an array of hashes.
- :local_threshold.

Raises:

(Error::InvalidCollectionName)

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 158


def initialize(database, name, options = {})
  raise Error::InvalidCollectionName.new unless name
  if options[:write] && options[:write_concern] && options[:write] != options[:write_concern]
    raise ArgumentError, "If :write and :write_concern are both given, they must be identical: #{options.inspect}"
  end
  @database = database
  @name = name.to_s.freeze
  @options = options.dup
=begin WriteConcern object support
  if @options[:write_concern].is_a?(WriteConcern::Base)
    # Cache the instance so that we do not needlessly reconstruct it.
    @write_concern = @options[:write_concern]
    @options[:write_concern] = @write_concern.options
  end
=end
  @options.freeze
end

Instance Attribute Details

#capped? ⇒ `true` | `false` (readonly)

Is the collection capped?

Examples:

Is the collection capped?

collection.capped?

Returns:

(true | false) —

If the collection is capped.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 316


def capped?
  database.list_collections(filter: { name: name })
    .first
    &.dig('options', CAPPED) || false
end

#database ⇒ Mongo::Database (readonly)

Returns:

(Mongo::Database) —

The database the collection resides in.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 46


attr_reader :database

#name ⇒ `String` (readonly)

Returns:

(String) —

The name of the collection.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 49


attr_reader :name

#options ⇒ `Hash` (readonly)

Returns:

(Hash) —

The collection options.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 52


attr_reader :options

#system_collection? ⇒ `Boolean` (readonly)

This method is for internal use only.

Whether the collection is a system collection.

Returns:

(Boolean) —

Whether the system is a system collection.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 1152


def system_collection?
  name.start_with?('system.')
end

Instance Method Details

#==(other) ⇒ `true` | `false`

Check if a collection is equal to another object. Will check the name and the database for equality.

Examples:

Check collection equality.

collection == other

Parameters:

other (Object) —

The object to check.

Returns:

(true | false) —

If the objects are equal.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 89


def ==(other)
  return false unless other.is_a?(Collection)
  name == other.name && database == other.database && options == other.options
end

#aggregate(pipeline, options = {}) ⇒ View::Aggregation

Perform an aggregation on the collection.

Examples:

Perform an aggregation.

collection.aggregate([ { "$group" => { "_id" => "$city", "tpop" => { "$sum" => "$pop" }}} ])

Parameters:

pipeline (Array<Hash>) —

The aggregation pipeline.
options (Hash) (defaults to: {}) —

The aggregation options.

Options Hash (options):

:allow_disk_use (true | false) —

Set to true if disk usage is allowed during the aggregation.
:batch_size (Integer) —

The number of documents to return per batch.
:bypass_document_validation (true | false) —

Whether or not to skip document level validation.
:collation (Hash) —

The collation to use.
:comment (Object) —

A user-provided comment to attach to this command.
:hint (String) —

The index to use for the aggregation.
:let (Hash) —

Mapping of variables to use in the pipeline. See the server documentation for details.
:max_time_ms (Integer) —

The maximum amount of time in milliseconds to allow the aggregation to run.
:use_cursor (true | false) —

Indicates whether the command will request that the server provide results using a cursor. Note that as of server version 3.6, aggregations always provide results using a cursor and this option is therefore not valid.
:session (Session) —

The session to use.

Returns:

(View::Aggregation) —

The aggregation object.

Since:

2.1.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 540


def aggregate(pipeline, options = {})
  View.new(self, {}, options).aggregate(pipeline, options)
end

#bulk_write(requests, options = {}) ⇒ BulkWrite::Result

Execute a batch of bulk write operations.

Examples:

Execute a bulk write.

collection.bulk_write(operations, options)

Parameters:

requests (Enumerable<Hash>) —

The bulk write requests.
options (Hash) (defaults to: {}) —

The options.

Options Hash (options):

:ordered (true | false) —

Whether the operations should be executed in order.
:write_concern (Hash) —

The write concern options. Can be :w => Integer, :fsync => Boolean, :j => Boolean.
:bypass_document_validation (true | false) —

Whether or not to skip document level validation.
:session (Session) —

The session to use for the set of operations.
:let (Hash) —

Mapping of variables to use in the command. See the server documentation for details.

Returns:

(BulkWrite::Result) —

The result of the operation.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 871


def bulk_write(requests, options = {})
  BulkWrite.new(self, requests, options).execute
end

#count(filter = nil, options = {}) ⇒ `Integer`

Deprecated.

Use #count_documents or estimated_document_count instead. However, note that the following operators will need to be substituted when switching to #count_documents:

* $where should be replaced with $expr (only works on 3.6+)
* $near should be replaced with $geoWithin with $center
* $nearSphere should be replaced with $geoWithin with $centerSphere

Gets an estimated number of matching documents in the collection.

Examples:

Get the count.

collection.count(name: 1)

Parameters:

filter (Hash) (defaults to: nil) —

A filter for matching documents.
options (Hash) (defaults to: {}) —

The count options.

Options Hash (options):

:hint (Hash) —

The index to use.
:limit (Integer) —

The maximum number of documents to count.
:max_time_ms (Integer) —

The maximum amount of time to allow the command to run.
:skip (Integer) —

The number of documents to skip before counting.
:read (Hash) —

The read preference options.
:collation (Hash) —

The collation to use.
:session (Session) —

The session to use.
:comment (Object) —

A user-provided comment to attach to this command.

Returns:

(Integer) —

The document count.

Since:

2.1.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 644


def count(filter = nil, options = {})
  View.new(self, filter || {}, options).count(options)
end

#count_documents(filter = {}, options = {}) ⇒ `Integer`

Gets the number of documents matching the query. Unlike the deprecated #count method, this will return the exact number of documents matching the filter (or exact number of documents in the collection, if no filter is provided) rather than an estimate.

Use #estimated_document_count to retrieve an estimate of the number of documents in the collection using the collection metadata.

Parameters:

filter (Hash) (defaults to: {}) —

A filter for matching documents.
options (Hash) (defaults to: {}) —

Options for the operation.

Options Hash (options):

:skip (Integer) —

The number of documents to skip.
:hint (Hash) —

Override default index selection and force MongoDB to use a specific index for the query. Requires server version 3.6+.
:limit (Integer) —

Max number of docs to count.
:max_time_ms (Integer) —

The maximum amount of time to allow the command to run.
:read (Hash) —

The read preference options.
:collation (Hash) —

The collation to use.
:session (Session) —

The session to use.
:comment (Object) —

A user-provided comment to attach to this command.

Returns:

(Integer) —

The document count.

Since:

2.6.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 674


def count_documents(filter = {}, options = {})
  View.new(self, filter, options).count_documents(options)
end

#create(opts = {}) ⇒ `Result`

Force the collection to be created in the database.

Examples:

Force the collection to be created.

collection.create

Parameters:

opts (Hash) (defaults to: {}) —

The options for the create operation.

Options Hash (opts):

:capped (true | false) —

Create a fixed-sized collection.
:change_stream_pre_and_post_images (Hash) —
Used to enable pre- and post-images on the created collection. The hash may have the following items:
- :enabled – true or false.
:clustered_index (Hash) —
Create a clustered index. This option specifies how this collection should be clustered on _id. The hash may have the following items:
- :key – The clustered index key field. Must be set to { _id: 1 }.
- :unique – Must be set to true. The collection will not accept inserted or updated documents where the clustered index key value matches an existing value in the index.
- :name – Optional. A name that uniquely identifies the clustered index.
:collation (Hash) —

The collation to use when creating the collection. This option will not be sent to the server when calling collection methods.
:encrypted_fields (Hash) —

Hash describing encrypted fields for queryable encryption.
:expire_after (Integer) —

Number indicating after how many seconds old time-series data should be deleted.
:max (Integer) —

The maximum number of documents in a capped collection. The size limit takes precedents over max.
:pipeline (Array<Hash>) —

An array of pipeline stages. A view will be created by applying this pipeline to the view_on collection or view.
:session (Session) —

The session to use for the operation.
:size (Integer) —

The size of the capped collection.
:time_series (Hash) —
Create a time-series collection. The hash may have the following items:
- :timeField – The name of the field which contains the date in each time series document.
- :metaField – The name of the field which contains metadata in each time series document.
- :granularity – Set the granularity to the value that is the closest match to the time span between consecutive incoming measurements. Possible values are “seconds” (default), “minutes”, and “hours”.
:validator (Hash) —

Hash describing document validation options for the collection.
:view_on (String) —

The name of the source collection or view from which to create a view.
:write (Hash) —

Deprecated. Equivalent to :write_concern option.
:write_concern (Hash) —

The write concern options. Can be :w => Integer|String, :fsync => Boolean, :j => Boolean.

Returns:

(Result) —

The result of the command.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 377


def create(opts = {})
  # Passing read options to create command causes it to break.
  # Filter the read options out. Session is also excluded here as it gets
  # used by the call to with_session and should not be part of the
  # operation. If it gets passed to the operation it would fail BSON
  # serialization.
  # TODO put the list of read options in a class-level constant when
  # we figure out what the full set of them is.
  options = Hash[self.options.merge(opts).reject do |key, value|
    %w(read read_preference read_concern session).include?(key.to_s)
  end]
  # Converting Ruby options to server style.
  CREATE_COLLECTION_OPTIONS.each do |ruby_key, server_key|
    if options.key?(ruby_key)
      options[server_key] = options.delete(ruby_key)
    end
  end
  operation = { :create => name }.merge(options)
  operation.delete(:write)
  operation.delete(:write_concern)
  client.send(:with_session, opts) do |session|
    write_concern = if opts[:write_concern]
      WriteConcern.get(opts[:write_concern])
    else
      self.write_concern
    end

    context = Operation::Context.new(client: client, session: session)
    maybe_create_qe_collections(opts[:encrypted_fields], client, session) do |encrypted_fields|
      Operation::Create.new(
        selector: operation,
        db_name: database.name,
        write_concern: write_concern,
        session: session,
        # Note that these are collection options, collation isn't
        # taken from options passed to the create method.
        collation: options[:collation] || options['collation'],
        encrypted_fields: encrypted_fields,
        validator: options[:validator],
      ).execute(next_primary(nil, session), context: context)
    end
  end
end

#delete_many(filter = nil, options = {}) ⇒ `Result`

Remove documents from the collection.

Examples:

Remove multiple documents from the collection.

collection.delete_many

Parameters:

filter (Hash) (defaults to: nil) —

The filter to use.
options (Hash) (defaults to: {}) —

The options.

Options Hash (options):

:collation (Hash) —

The collation to use.
:session (Session) —

The session to use.
:hint (Hash | String) —

The index to use for this operation. May be specified as a Hash (e.g. { _id: 1 }) or a String (e.g. “id”).
:let (Hash) —

Mapping of variables to use in the command. See the server documentation for details.

Returns:

(Result) —

The response from the database.

Since:

2.1.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 915


def delete_many(filter = nil, options = {})
  find(filter, options).delete_many(options)
end

#delete_one(filter = nil, options = {}) ⇒ `Result`

Remove a document from the collection.

Examples:

Remove a single document from the collection.

collection.delete_one

Parameters:

filter (Hash) (defaults to: nil) —

The filter to use.
options (Hash) (defaults to: {}) —

The options.

Options Hash (options):

:collation (Hash) —

The collation to use.
:session (Session) —

The session to use.
:hint (Hash | String) —

The index to use for this operation. May be specified as a Hash (e.g. { _id: 1 }) or a String (e.g. “id”).
:let (Hash) —

Mapping of variables to use in the command. See the server documentation for details.

Returns:

(Result) —

The response from the database.

Since:

2.1.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 893


def delete_one(filter = nil, options = {})
  find(filter, options).delete_one(options)
end

#distinct(field_name, filter = nil, options = {}) ⇒ `Array`<`Object`>

Get a list of distinct values for a specific field.

Examples:

Get the distinct values.

collection.distinct('name')

Parameters:

field_name (Symbol, String) —

The name of the field.
filter (Hash) (defaults to: nil) —

The documents from which to retrieve the distinct values.
options (Hash) (defaults to: {}) —

The distinct command options.

Options Hash (options):

:max_time_ms (Integer) —

The maximum amount of time to allow the command to run.
:read (Hash) —

The read preference options.
:collation (Hash) —

The collation to use.
:session (Session) —

The session to use.

Returns:

(Array<Object>) —

The list of distinct values.

Since:

2.1.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 716


def distinct(field_name, filter = nil, options = {})
  View.new(self, filter || {}, options).distinct(field_name, options)
end

#drop(opts = {}) ⇒ `Result`

Note:

An error returned if the collection doesn’t exist is suppressed.

Drop the collection. Will also drop all indexes associated with the collection, as well as associated queryable encryption collections.

Examples:

Drop the collection.

collection.drop

Parameters:

opts (Hash) (defaults to: {}) —

The options for the drop operation.

Options Hash (opts):

:session (Session) —

The session to use for the operation.
:write_concern (Hash) —

The write concern options.
:encrypted_fields (Hash | nil) —

Encrypted fields hash that was provided to ‘create` collection helper.

Returns:

(Result) —

The result of the command.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 439


def drop(opts = {})
  client.send(:with_session, opts) do |session|
    maybe_drop_emm_collections(opts[:encrypted_fields], client, session) do
      temp_write_concern = write_concern
      write_concern = if opts[:write_concern]
        WriteConcern.get(opts[:write_concern])
      else
        temp_write_concern
      end
      context = Operation::Context.new(client: client, session: session)
      operation = Operation::Drop.new({
        selector: { :drop => name },
        db_name: database.name,
        write_concern: write_concern,
        session: session,
      })
      do_drop(operation, session, context)
    end
  end
end

#estimated_document_count(options = {}) ⇒ `Integer`

Gets an estimate of the number of documents in the collection using the collection metadata.

Use #count_documents to retrieve the exact number of documents in the collection, or to count documents matching a filter.

Parameters:

options (Hash) (defaults to: {}) —

Options for the operation.

Options Hash (options):

:max_time_ms (Integer) —

The maximum amount of time to allow the command to run for on the server.
:read (Hash) —

The read preference options.
:comment (Object) —

A user-provided comment to attach to this command.

Returns:

(Integer) —

The document count.

Since:

2.6.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 695


def estimated_document_count(options = {})
  View.new(self, {}, options).estimated_document_count(options)
end

#find(filter = nil, options = {}) ⇒ `CollectionView`

Find documents in the collection.

Examples:

Find documents in the collection by a selector.

collection.find(name: 1)

Get all documents in a collection.

collection.find

Parameters:

filter (Hash) (defaults to: nil) —

The filter to use in the find.
options (Hash) (defaults to: {}) —

The options for the find.

Options Hash (options):

:allow_disk_use (true | false) —

When set to true, the server can write temporary data to disk while executing the find operation. This option is only available on MongoDB server versions 4.4 and newer.
:allow_partial_results (true | false) —

Allows the query to get partial results if some shards are down.
:batch_size (Integer) —

The number of documents returned in each batch of results from MongoDB.
:collation (Hash) —

The collation to use.
:comment (Object) —

A user-provided comment to attach to this command.
:cursor_type (:tailable, :tailable_await) —

The type of cursor to use.
:limit (Integer) —

The max number of docs to return from the query.
:max_time_ms (Integer) —

The maximum amount of time to allow the query to run, in milliseconds.
:modifiers (Hash) —

A document containing meta-operators modifying the output or behavior of a query.
:no_cursor_timeout (true | false) —

The server normally times out idle cursors after an inactivity period (10 minutes) to prevent excess memory use. Set this option to prevent that.
:oplog_replay (true | false) —

For internal replication use only, applications should not set this option.
:projection (Hash) —

The fields to include or exclude from each doc in the result set.
:session (Session) —

The session to use.
:skip (Integer) —

The number of docs to skip before returning results.
:sort (Hash) —

The key and direction pairs by which the result set will be sorted.
:let (Hash) —

Mapping of variables to use in the command. See the server documentation for details.

Returns:

(CollectionView) —

The collection view.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 505


def find(filter = nil, options = {})
  View.new(self, filter || {}, options)
end

#find_one_and_delete(filter, options = {}) ⇒ `BSON::Document`^?

Finds a single document in the database via findAndModify and deletes it, returning the original document.

Examples:

Find one document and delete it.

collection.find_one_and_delete(name: 'test')

Parameters:

filter (Hash) —

The filter to use.
options (Hash) (defaults to: {}) —

The options.

Options Hash (options):

:max_time_ms (Integer) —

The maximum amount of time to allow the command to run in milliseconds.
:projection (Hash) —

The fields to include or exclude in the returned doc.
:sort (Hash) —

The key and direction pairs by which the result set will be sorted.
:write_concern (Hash) —

The write concern options. Defaults to the collection’s write concern.
:collation (Hash) —

The collation to use.
:session (Session) —

The session to use.
:hint (Hash | String) —

The index to use for this operation. May be specified as a Hash (e.g. { _id: 1 }) or a String (e.g. “id”).
:let (Hash) —

Mapping of variables to use in the command. See the server documentation for details.

Returns:

(BSON::Document, nil) —

The document, if found.

Since:

2.1.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 1053


def find_one_and_delete(filter, options = {})
  find(filter, options).find_one_and_delete(options)
end

#find_one_and_replace(filter, replacement, options = {}) ⇒ `BSON::Document`

Finds a single document and replaces it, returning the original doc unless otherwise specified.

Examples:

Find a document and replace it, returning the original.

collection.find_one_and_replace({ name: 'test' }, { name: 'test1' })

Find a document and replace it, returning the new document.

collection.find_one_and_replace({ name: 'test' }, { name: 'test1' }, :return_document => :after)

Parameters:

filter (Hash) —

The filter to use.
replacement (BSON::Document) —

The replacement document.
options (Hash) (defaults to: {}) —

The options.

Options Hash (options):

:max_time_ms (Integer) —

The maximum amount of time to allow the command to run in milliseconds.
:projection (Hash) —

The fields to include or exclude in the returned doc.
:sort (Hash) —

The key and direction pairs by which the result set will be sorted.
:return_document (Symbol) —

Either :before or :after.
:upsert (true | false) —

Whether to upsert if the document doesn’t exist.
:bypass_document_validation (true | false) —

Whether or not to skip document level validation.
:write_concern (Hash) —

The write concern options. Defaults to the collection’s write concern.
:collation (Hash) —

The collation to use.
:session (Session) —

The session to use.
:hint (Hash | String) —

The index to use for this operation. May be specified as a Hash (e.g. { _id: 1 }) or a String (e.g. “id”).
:let (Hash) —

Mapping of variables to use in the command. See the server documentation for details.

Returns:

(BSON::Document) —

The document.

Since:

2.1.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 1131


def find_one_and_replace(filter, replacement, options = {})
  find(filter, options).find_one_and_update(replacement, options)
end

#find_one_and_update(filter, update, options = {}) ⇒ `BSON::Document`

Finds a single document via findAndModify and updates it, returning the original doc unless otherwise specified.

Examples:

Find a document and update it, returning the original.

collection.find_one_and_update({ name: 'test' }, { "$set" => { name: 'test1' }})

Find a document and update it, returning the updated document.

collection.find_one_and_update({ name: 'test' }, { "$set" => { name: 'test1' }}, :return_document => :after)

Parameters:

filter (Hash) —

The filter to use.
update (Hash | Array<Hash>) —

The update document or pipeline.
options (Hash) (defaults to: {}) —

The options.

Options Hash (options):

:max_time_ms (Integer) —

The maximum amount of time to allow the command to run in milliseconds.
:projection (Hash) —

The fields to include or exclude in the returned doc.
:sort (Hash) —

The key and direction pairs by which the result set will be sorted.
:return_document (Symbol) —

Either :before or :after.
:upsert (true | false) —

Whether to upsert if the document doesn’t exist.
:bypass_document_validation (true | false) —

Whether or not to skip document level validation.
:write_concern (Hash) —

The write concern options. Defaults to the collection’s write concern.
:collation (Hash) —

The collation to use.
:array_filters (Array) —

A set of filters specifying to which array elements an update should apply.
:session (Session) —

The session to use.
:hint (Hash | String) —

The index to use for this operation. May be specified as a Hash (e.g. { _id: 1 }) or a String (e.g. “id”).
:let (Hash) —

Mapping of variables to use in the command. See the server documentation for details.

Returns:

(BSON::Document) —

The document.

Since:

2.1.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 1093


def find_one_and_update(filter, update, options = {})
  find(filter, options).find_one_and_update(update, options)
end

#indexes(options = {}) ⇒ Index::View

Get a view of all indexes for this collection. Can be iterated or has more operations.

Examples:

Get the index view.

collection.indexes

Parameters:

options (Hash) (defaults to: {}) —

Options for getting a list of all indexes.

Options Hash (options):

:session (Session) —

The session to use.

Returns:

(Index::View) —

The index view.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 733


def indexes(options = {})
  Index::View.new(self, options)
end

#insert_many(documents, options = {}) ⇒ `Result`

Insert the provided documents into the collection.

Examples:

Insert documents into the collection.

collection.insert_many([{ name: 'test' }])

Parameters:

documents (Enumerable<Hash>) —

The documents to insert.
options (Hash) (defaults to: {}) —

The insert options.

Options Hash (options):

:bypass_document_validation (true | false) —

Whether or not to skip document level validation.
:comment (Object) —

A user-provided comment to attach to this command.
:ordered (true | false) —

Whether the operations should be executed in order.
:session (Session) —

The session to use for the operation.
:write_concern (Hash) —

The write concern options. Can be :w => Integer, :fsync => Boolean, :j => Boolean.

Returns:

(Result) —

The database response wrapper.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 843


def insert_many(documents, options = {})
  QueryCache.clear_namespace(namespace)

  inserts = documents.map{ |doc| { :insert_one => doc }}
  bulk_write(inserts, options)
end

#insert_one(document, opts = {}) ⇒ `Result`

Insert a single document into the collection.

Examples:

Insert a document into the collection.

collection.insert_one({ name: 'test' })

Parameters:

document (Hash) —

The document to insert.
opts (Hash) (defaults to: {}) —

The insert options.

Options Hash (opts):

:bypass_document_validation (true | false) —

Whether or not to skip document level validation.
:comment (Object) —

A user-provided comment to attach to this command.
:session (Session) —

The session to use for the operation.
:write_concern (Hash) —

The write concern options. Can be :w => Integer, :fsync => Boolean, :j => Boolean.

Returns:

(Result) —

The database response wrapper.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 790


def insert_one(document, opts = {})
  QueryCache.clear_namespace(namespace)

  client.with_session(opts) do |session|
    write_concern = if opts[:write_concern]
      WriteConcern.get(opts[:write_concern])
    else
      write_concern_with_session(session)
    end

    if document.nil?
      raise ArgumentError, "Document to be inserted cannot be nil"
    end

    context = Operation::Context.new(client: client, session: session)
    write_with_retry(write_concern, context: context) do |connection, txn_num, context|
      Operation::Insert.new(
        :documents => [ document ],
        :db_name => database.name,
        :coll_name => name,
        :write_concern => write_concern,
        :bypass_document_validation => !!opts[:bypass_document_validation],
        :options => opts,
        :id_generator => client.options[:id_generator],
        :session => session,
        :txn_num => txn_num,
        :comment => opts[:comment]
      ).execute_with_connection(connection, context: context)
    end
  end
end

#inspect ⇒ `String`

Get a pretty printed string inspection for the collection.

Examples:

Inspect the collection.

collection.inspect

Returns:

(String) —

The collection inspection.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 767


def inspect
  "#<Mongo::Collection:0x#{object_id} namespace=#{namespace}>"
end

#namespace ⇒ `String`

Get the fully qualified namespace of the collection.

Examples:

Get the fully qualified namespace.

collection.namespace

Returns:

(String) —

The collection namespace.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 1143


def namespace
  "#{database.name}.#{name}"
end

#parallel_scan(cursor_count, options = {}) ⇒ `Array`<Cursor>

Execute a parallel scan on the collection view.

Returns a list of up to cursor_count cursors that can be iterated concurrently. As long as the collection is not modified during scanning, each document appears once in one of the cursors’ result sets.

Examples:

Execute a parallel collection scan.

collection.parallel_scan(2)

Parameters:

cursor_count (Integer) —

The max number of cursors to return.
options (Hash) (defaults to: {}) —

The parallel scan command options.

Options Hash (options):

:max_time_ms (Integer) —

The maximum amount of time to allow the command to run in milliseconds.
:session (Session) —

The session to use.

Returns:

(Array<Cursor>) —

An array of cursors.

Since:

[ GitHub ]

# File 'lib/mongo/collection.rb', line 938


def parallel_scan(cursor_count, options = {})
  find({}, options).send(:parallel_scan, cursor_count, options)
end

#read_concern ⇒ `Hash`

Get the effective read concern for this collection instance.

If a read concern was provided in collection options, that read concern will be returned, otherwise the database’s effective read concern will be returned.

Examples:

Get the read concern.

collection.read_concern

Returns:

(Hash) —

The read concern.

Since:

2.2.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 188


def read_concern
  options[:read_concern] || database.read_concern
end

#read_preference ⇒ `Hash`

Get the effective read preference for this collection.

If a read preference was provided in collection options, that read preference will be returned, otherwise the database’s effective read preference will be returned.

Examples:

Get the read preference.

collection.read_preference

Returns:

(Hash) —

The read preference.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 216


def read_preference
  @read_preference ||= options[:read] || database.read_preference
end

#replace_one(filter, replacement, options = {}) ⇒ `Result`

Replaces a single document in the collection with the new document.

Examples:

Replace a single document.

collection.replace_one({ name: 'test' }, { name: 'test1' })

Parameters:

filter (Hash) —

The filter to use.
replacement (Hash) —

The replacement document..
options (Hash) (defaults to: {}) —

The options.

Options Hash (options):

:upsert (true | false) —

Whether to upsert if the document doesn’t exist.
:bypass_document_validation (true | false) —

Whether or not to skip document level validation.
:collation (Hash) —

The collation to use.
:session (Session) —

The session to use.
:hint (Hash | String) —

The index to use for this operation. May be specified as a Hash (e.g. { _id: 1 }) or a String (e.g. “id”).
:let (Hash) —

Mapping of variables to use in the command. See the server documentation for details.

Returns:

(Result) —

The response from the database.

Since:

2.1.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 965


def replace_one(filter, replacement, options = {})
  find(filter, options).replace_one(replacement, options)
end

#search_indexes(options = {}) ⇒ SearchIndex::View

Note:

Only one of id or name may be given; it is an error to specify both, although both may be omitted safely.

Get a view of all search indexes for this collection. Can be iterated or operated on directly. If id or name are given, the iterator will return only the indicated index. For all other operations, id and name are ignored.

Parameters:

options (Hash) (defaults to: {}) —

The options to use to configure the view.

Options Hash (options):

:id (String) —

The id of the specific index to query (optional)
:name (String) —

The name of the specific index to query (optional)
:aggregate (Hash) —

The options hash to pass to the aggregate command (optional)

Returns:

(SearchIndex::View) —

The search index view.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 755


def search_indexes(options = {})
  SearchIndex::View.new(self, options)
end

#server_selector ⇒ Mongo::ServerSelector

Get the server selector for this collection.

Examples:

Get the server selector.

collection.server_selector

Returns:

(Mongo::ServerSelector) —

The server selector.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 200


def server_selector
  @server_selector ||= ServerSelector.get(read_preference || database.server_selector)
end

#update_many(filter, update, options = {}) ⇒ `Result`

Update documents in the collection.

Examples:

Update multiple documents in the collection.

collection.update_many({ name: 'test'}, '$set' => { name: 'test1' })

Parameters:

filter (Hash) —

The filter to use.
update (Hash | Array<Hash>) —

The update document or pipeline.
options (Hash) (defaults to: {}) —

The options.

Options Hash (options):

:upsert (true | false) —

Whether to upsert if the document doesn’t exist.
:bypass_document_validation (true | false) —

Whether or not to skip document level validation.
:collation (Hash) —

The collation to use.
:array_filters (Array) —

A set of filters specifying to which array elements an update should apply.
:session (Session) —

The session to use.
:hint (Hash | String) —

The index to use for this operation. May be specified as a Hash (e.g. { _id: 1 }) or a String (e.g. “id”).
:let (Hash) —

Mapping of variables to use in the command. See the server documentation for details.

Returns:

(Result) —

The response from the database.

Since:

2.1.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 994


def update_many(filter, update, options = {})
  find(filter, options).update_many(update, options)
end

#update_one(filter, update, options = {}) ⇒ `Result`

Update a single document in the collection.

Examples:

Update a single document in the collection.

collection.update_one({ name: 'test'}, '$set' => { name: 'test1'})

Parameters:

filter (Hash) —

The filter to use.
update (Hash | Array<Hash>) —

The update document or pipeline.
options (Hash) (defaults to: {}) —

The options.

Options Hash (options):

:upsert (true | false) —

Whether to upsert if the document doesn’t exist.
:bypass_document_validation (true | false) —

Whether or not to skip document level validation.
:collation (Hash) —

The collation to use.
:array_filters (Array) —

A set of filters specifying to which array elements an update should apply.
:session (Session) —

The session to use.
:hint (Hash | String) —

The index to use for this operation. May be specified as a Hash (e.g. { _id: 1 }) or a String (e.g. “id”).
:let (Hash) —

Mapping of variables to use in the command. See the server documentation for details.

Returns:

(Result) —

The response from the database.

Since:

2.1.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 1023


def update_one(filter, update, options = {})
  find(filter, options).update_one(update, options)
end

#watch(pipeline = [], options = {}) ⇒ `ChangeStream`

Note:

A change stream only allows ‘majority’ read concern.

Note:

This helper method is preferable to running a raw aggregation with a $changeStream stage, for the purpose of supporting resumability.

As of version 3.6 of the MongoDB server, a “$changeStream“ pipeline stage is supported in the aggregation framework. This stage allows users to request that notifications are sent for all changes to a particular collection.

Examples:

Get change notifications for a given collection.

collection.watch([{ '$match' => { operationType: { '$in' => ['insert', 'replace'] } } }])

Parameters:

pipeline (Array<Hash>) (defaults to: []) —

Optional additional filter operators.
options (Hash) (defaults to: {}) —

The change stream options.

Options Hash (options):

:full_document (String) —

Allowed values: nil, ‘default’, ‘updateLookup’, ‘whenAvailable’, ‘required’.

The default is to not send a value (i.e. nil), which is equivalent to ‘default’. By default, the change notification for partial updates will include a delta describing the changes to the document.

When set to ‘updateLookup’, the change notification for partial updates will include both a delta describing the changes to the document as well as a copy of the entire document that was changed from some time after the change occurred.

When set to ‘whenAvailable’, configures the change stream to return the post-image of the modified document for replace and update change events if the post-image for this event is available.

When set to ‘required’, the same behavior as ‘whenAvailable’ except that an error is raised if the post-image is not available.
:full_document_before_change (String) —

Allowed values: nil, ‘whenAvailable’, ‘required’, ‘off’.

The default is to not send a value (i.e. nil), which is equivalent to ‘off’.

When set to ‘whenAvailable’, configures the change stream to return the pre-image of the modified document for replace, update, and delete change events if it is available.

When set to ‘required’, the same behavior as ‘whenAvailable’ except that an error is raised if the pre-image is not available.
:resume_after (BSON::Document, Hash) —

Specifies the logical starting point for the new change stream.
:max_await_time_ms (Integer) —

The maximum amount of time for the server to wait on new documents to satisfy a change stream query.
:batch_size (Integer) —

The number of documents to return per batch.
:collation (BSON::Document, Hash) —

The collation to use.
:session (Session) —

The session to use.
:start_at_operation_time (BSON::Timestamp) —

Only return changes that occurred at or after the specified timestamp. Any command run against the server will return a cluster time that can be used here. Only recognized by server versions 4.0+.
:comment (Object) —

A user-provided comment to attach to this command.
:show_expanded_events (Boolean) —

Enables the server to send the ‘expanded’ list of change stream events. The list of additional events included with this flag set are: createIndexes, dropIndexes, modify, create, shardCollection, reshardCollection, refineCollectionShardKey.

Returns:

(ChangeStream) —

The change stream object.

Since:

2.5.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 611


def watch(pipeline = [], options = {})
  view_options = options.dup
  view_options[:await_data] = true if options[:max_await_time_ms]
  View::ChangeStream.new(View.new(self, {}, view_options), pipeline, nil, options)
end

#with(new_options) ⇒ `Collection`

Examples:

Get a collection with a changed read concern.

collection.with(read_concern: { level: :majority })

Get a collection with a changed write concern.

collection.with(write_concern: { w:  3 })

Parameters:

new_options (Hash) —

The new options to use.

Options Hash (new_options):

:read (Hash) —
The read preference options. The hash may have the following items:
- :mode – read preference specified as a symbol; valid values are :primary, :primary_preferred, :secondary, :secondary_preferred and :nearest.
- :tag_sets – an array of hashes.
- :local_threshold.
:read_concern (Hash) —
The read concern options hash, with the following optional keys:
- :level – the read preference level as a symbol; valid values
```
are *:local*, *:majority*, and *:snapshot*
```
:write (Hash) —

Deprecated. Equivalent to :write_concern option.
:write_concern (Hash) —

The write concern options. Can be :w => Integer|String, :fsync => Boolean, :j => Boolean.

Returns:

(Collection) —

A new collection instance.

Since:

2.1.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 294


def with(new_options)
  new_options.keys.each do |k|
    raise Error::UnchangeableCollectionOption.new(k) unless CHANGEABLE_OPTIONS.include?(k)
  end
  options = @options.dup
  if options[:write] && new_options[:write_concern]
    options.delete(:write)
  end
  if options[:write_concern] && new_options[:write]
    options.delete(:write_concern)
  end
  Collection.new(database, name, options.update(new_options))
end

#write_concern ⇒ Mongo::WriteConcern

Get the effective write concern on this collection.

If a write concern was provided in collection options, that write concern will be returned, otherwise the database’s effective write concern will be returned.

Examples:

Get the write concern.

collection.write_concern

Returns:

(Mongo::WriteConcern) —

The write concern.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 232


def write_concern
  @write_concern ||= WriteConcern.get(
    options[:write_concern] || options[:write] || database.write_concern)
end

#write_concern_with_session(session) ⇒ Mongo::WriteConcern

This method is for internal use only.

Get the write concern to use for an operation on this collection, given a session.

If the session is in a transaction and the collection has an unacknowledged write concern, remove the write concern’s :w option. Otherwise, return the unmodified write concern.

Returns:

(Mongo::WriteConcern) —

The write concern.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/collection.rb', line 248


def write_concern_with_session(session)
  wc = write_concern
  if session && session.in_transaction?
    if wc && !wc.acknowledged?
      opts = wc.options.dup
      opts.delete(:w)
      return WriteConcern.get(opts)
    end
  end
  wc
end

Class: Mongo::Collection

Overview

Constant Summary

QueryableEncryption - Included

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Helpers - Included

QueryableEncryption - Included

Retryable - Included

Constructor Details

.new(database, name, options = {}) ⇒ Collection

Instance Attribute Details

#capped? ⇒ true | false (readonly)

#database ⇒ Mongo::Database (readonly)

#name ⇒ String (readonly)

#options ⇒ Hash (readonly)

#system_collection? ⇒ Boolean (readonly)

Instance Method Details

#==(other) ⇒ true | false

#aggregate(pipeline, options = {}) ⇒ View::Aggregation

#bulk_write(requests, options = {}) ⇒ BulkWrite::Result

#count(filter = nil, options = {}) ⇒ Integer

#count_documents(filter = {}, options = {}) ⇒ Integer

#create(opts = {}) ⇒ Result

#delete_many(filter = nil, options = {}) ⇒ Result

#delete_one(filter = nil, options = {}) ⇒ Result

#distinct(field_name, filter = nil, options = {}) ⇒ Array<Object>

#drop(opts = {}) ⇒ Result

#estimated_document_count(options = {}) ⇒ Integer

#find(filter = nil, options = {}) ⇒ CollectionView

#find_one_and_delete(filter, options = {}) ⇒ BSON::Document?

#find_one_and_replace(filter, replacement, options = {}) ⇒ BSON::Document

#find_one_and_update(filter, update, options = {}) ⇒ BSON::Document

#indexes(options = {}) ⇒ Index::View

#insert_many(documents, options = {}) ⇒ Result

#insert_one(document, opts = {}) ⇒ Result

#inspect ⇒ String

#namespace ⇒ String

#parallel_scan(cursor_count, options = {}) ⇒ Array<Cursor>

#read_concern ⇒ Hash

#read_preference ⇒ Hash

#replace_one(filter, replacement, options = {}) ⇒ Result

#search_indexes(options = {}) ⇒ SearchIndex::View

#server_selector ⇒ Mongo::ServerSelector

#update_many(filter, update, options = {}) ⇒ Result

#update_one(filter, update, options = {}) ⇒ Result

#watch(pipeline = [], options = {}) ⇒ ChangeStream

#with(new_options) ⇒ Collection

#write_concern ⇒ Mongo::WriteConcern

#write_concern_with_session(session) ⇒ Mongo::WriteConcern

`QueryableEncryption` - Included

`Helpers` - Included

`QueryableEncryption` - Included

`Retryable` - Included

.new(database, name, options = {}) ⇒ `Collection`

#capped? ⇒ `true` | `false` (readonly)

#name ⇒ `String` (readonly)

#options ⇒ `Hash` (readonly)

#system_collection? ⇒ `Boolean` (readonly)

#==(other) ⇒ `true` | `false`

#count(filter = nil, options = {}) ⇒ `Integer`

#count_documents(filter = {}, options = {}) ⇒ `Integer`

#create(opts = {}) ⇒ `Result`

#delete_many(filter = nil, options = {}) ⇒ `Result`

#delete_one(filter = nil, options = {}) ⇒ `Result`

#distinct(field_name, filter = nil, options = {}) ⇒ `Array`<`Object`>

#drop(opts = {}) ⇒ `Result`

#estimated_document_count(options = {}) ⇒ `Integer`

#find(filter = nil, options = {}) ⇒ `CollectionView`

#find_one_and_delete(filter, options = {}) ⇒ `BSON::Document`^?

#find_one_and_replace(filter, replacement, options = {}) ⇒ `BSON::Document`

#find_one_and_update(filter, update, options = {}) ⇒ `BSON::Document`

#insert_many(documents, options = {}) ⇒ `Result`

#insert_one(document, opts = {}) ⇒ `Result`

#inspect ⇒ `String`

#namespace ⇒ `String`

#parallel_scan(cursor_count, options = {}) ⇒ `Array`<Cursor>

#read_concern ⇒ `Hash`

#read_preference ⇒ `Hash`

#replace_one(filter, replacement, options = {}) ⇒ `Result`

#update_many(filter, update, options = {}) ⇒ `Result`

#update_one(filter, update, options = {}) ⇒ `Result`

#watch(pipeline = [], options = {}) ⇒ `ChangeStream`

#with(new_options) ⇒ `Collection`