Provided by: libmongodb-perl_2.2.2-2_all 
NAME
MongoDB::Collection - A MongoDB Collection
VERSION
version v2.2.2
SYNOPSIS
# get a Collection via the Database object
$coll = $db->get_collection("people");
# insert a document
$coll->insert_one( { name => "John Doe", age => 42 } );
# insert one or more documents
$coll->insert_many( \@documents );
# delete a document
$coll->delete_one( { name => "John Doe" } );
# update a document
$coll->update_one( { name => "John Doe" }, { '$inc' => { age => 1 } } );
# find a single document
$doc = $coll->find_one( { name => "John Doe" } )
# Get a MongoDB::Cursor for a query
$cursor = $coll->find( { age => 42 } );
# Cursor iteration
while ( my $doc = $cursor->next ) {
...
}
DESCRIPTION
This class models a MongoDB collection and provides an API for interacting with it.
Generally, you never construct one of these directly with "new". Instead, you call "get_collection" on a
MongoDB::Database object.
USAGE
Error handling
Unless otherwise explicitly documented, all methods throw exceptions if an error occurs. The error types
are documented in MongoDB::Error.
To catch and handle errors, the Try::Tiny and Safe::Isa modules are recommended:
use Try::Tiny;
use Safe::Isa; # provides $_isa
try {
$coll->insert_one( $doc )
}
catch {
if ( $_->$_isa("MongoDB::DuplicateKeyError" ) {
...
}
else {
...
}
};
To retry failures automatically, consider using Try::Tiny::Retry.
Transactions
To conduct operations in a transactions, get a MongoDB::ClientSession from "start_session" in
MongoDB::MongoClient. Start the transaction on the session using "start_transaction" and pass the
session as an option to all operations. Then call "commit_transaction" or "abort_transaction" on the
session. See the MongoDB::ClientSession for options and usage details.
For detailed instructions on using transactions with MongoDB, see the MongoDB manual page: Transactions
<https://docs.mongodb.com/master/core/transactions>.
Terminology
Document
A collection of key-value pairs. A Perl hash is a document. Array references with an even number of
elements and Tie::IxHash objects may also be used as documents.
Ordered document
Many MongoDB::Collection method parameters or options require an ordered document: an ordered list of
key/value pairs. Perl's hashes are not ordered and since Perl v5.18 are guaranteed to have random order.
Therefore, when an ordered document is called for, you may use an array reference of pairs or a
Tie::IxHash object. You may use a hash reference if there is only one key/value pair.
Filter expression
A filter expression provides the query criteria <http://docs.mongodb.org/manual/tutorial/query-
documents/> to select a document for deletion. It must be an "Ordered document".
ATTRIBUTES
database
The MongoDB::Database representing the database that contains the collection.
name
The name of the collection.
read_preference
A MongoDB::ReadPreference object. It may be initialized with a string corresponding to one of the valid
read preference modes or a hash reference that will be coerced into a new MongoDB::ReadPreference object.
By default it will be inherited from a MongoDB::Database object.
write_concern
A MongoDB::WriteConcern object. It may be initialized with a hash reference that will be coerced into a
new MongoDB::WriteConcern object. By default it will be inherited from a MongoDB::Database object.
read_concern
A MongoDB::ReadConcern object. May be initialized with a hash reference or a string that will be coerced
into the level of read concern.
By default it will be inherited from a MongoDB::Database object.
max_time_ms
Specifies the default maximum amount of time in milliseconds that the server should use for working on a
query.
Note: this will only be used for server versions 2.6 or greater, as that was when the $maxTimeMS meta-
operator was introduced.
bson_codec
An object that provides the "encode_one" and "decode_one" methods, such as from BSON. It may be
initialized with a hash reference that will be coerced into a new BSON object. By default it will be
inherited from a MongoDB::Database object.
METHODS
client
$client = $coll->client;
Returns the MongoDB::MongoClient object associated with this object.
full_name
$full_name = $coll->full_name;
Returns the full name of the collection, including the namespace of the database it's in prefixed with a
dot character. E.g. collection "foo" in database "test" would result in a "full_name" of "test.foo".
indexes
$indexes = $collection->indexes;
$collection->indexes->create_one( [ x => 1 ], { unique => 1 } );
$collection->indexes->drop_all;
Returns a MongoDB::IndexView object for managing the indexes associated with the collection.
clone
$coll2 = $coll1->clone( write_concern => { w => 2 } );
Constructs a copy of the original collection, but allows changing attributes in the copy.
with_codec
$coll2 = $coll1->with_codec( $new_codec );
$coll2 = $coll1->with_codec( prefer_numeric => 1 );
Constructs a copy of the original collection, but clones the "bson_codec". If given an object that does
"encode_one" and "decode_one", it is equivalent to:
$coll2 = $coll1->clone( bson_codec => $new_codec );
If given a hash reference or a list of key/value pairs, it is equivalent to:
$coll2 = $coll1->clone(
bson_codec => $coll1->bson_codec->clone( @list )
);
insert_one
$res = $coll->insert_one( $document );
$res = $coll->insert_one( $document, $options );
$id = $res->inserted_id;
Inserts a single document into the database and returns a MongoDB::InsertOneResult or
MongoDB::UnacknowledgedResult object.
If no "_id" field is present, one will be added when a document is serialized for the database without
modifying the original document. The generated "_id" may be retrieved from the result object.
An optional hash reference of options may be given.
Valid options include:
• "bypassDocumentValidation" - skips document validation, if enabled; this is ignored for MongoDB
servers older than version 3.2.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
insert_many
$res = $coll->insert_many( [ @documents ] );
$res = $coll->insert_many( [ @documents ], { ordered => 0 } );
Inserts each of the documents in an array reference into the database and returns a
MongoDB::InsertManyResult or MongoDB::UnacknowledgedResult. This is syntactic sugar for doing a
MongoDB::BulkWrite operation.
If no "_id" field is present, one will be added when a document is serialized for the database without
modifying the original document. The generated "_id" may be retrieved from the result object.
An optional hash reference of options may be provided.
Valid options include:
• "bypassDocumentValidation" - skips document validation, if enabled; this is ignored for MongoDB
servers older than version 3.2.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
• "ordered" – when true, the server will halt insertions after the first error (if any). When false,
all documents will be processed and any error will only be thrown after all insertions are attempted.
The default is true.
On MongoDB servers before version 2.6, "insert_many" bulk operations are emulated with individual inserts
to capture error information. On 2.6 or later, this method will be significantly faster than individual
"insert_one" calls.
delete_one
$res = $coll->delete_one( $filter );
$res = $coll->delete_one( { _id => $id } );
$res = $coll->delete_one( $filter, { collation => { locale => "en_US" } } );
Deletes a single document that matches a filter expression and returns a MongoDB::DeleteResult or
MongoDB::UnacknowledgedResult object.
A hash reference of options may be provided.
Valid options include:
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
delete_many
$res = $coll->delete_many( $filter );
$res = $coll->delete_many( { name => "Larry" } );
$res = $coll->delete_many( $filter, { collation => { locale => "en_US" } } );
Deletes all documents that match a filter expression and returns a MongoDB::DeleteResult or
MongoDB::UnacknowledgedResult object.
Valid options include:
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
replace_one
$res = $coll->replace_one( $filter, $replacement );
$res = $coll->replace_one( $filter, $replacement, { upsert => 1 } );
Replaces one document that matches a filter expression and returns a MongoDB::UpdateResult or
MongoDB::UnacknowledgedResult object.
The replacement document must not have any field-update operators in it (e.g. $set).
A hash reference of options may be provided.
Valid options include:
• "bypassDocumentValidation" - skips document validation, if enabled; this is ignored for MongoDB
servers older than version 3.2.
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
• "upsert" – defaults to false; if true, a new document will be added if one is not found
update_one
$res = $coll->update_one( $filter, $update );
$res = $coll->update_one( $filter, $update, { upsert => 1 } );
Updates one document that matches a filter expression and returns a MongoDB::UpdateResult or
MongoDB::UnacknowledgedResult object.
The update document must have only field-update operators in it (e.g. $set).
A hash reference of options may be provided.
Valid options include:
• "arrayFilters" - An array of filter documents that determines which array elements to modify for an
update operation on an array field. Only available for MongoDB servers of version 3.6+.
• "bypassDocumentValidation" - skips document validation, if enabled; this is ignored for MongoDB
servers older than version 3.2.
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
• "upsert" – defaults to false; if true, a new document will be added if one is not found by taking the
filter expression and applying the update document operations to it prior to insertion.
update_many
$res = $coll->update_many( $filter, $update );
$res = $coll->update_many( $filter, $update, { upsert => 1 } );
Updates one or more documents that match a filter expression and returns a MongoDB::UpdateResult or
MongoDB::UnacknowledgedResult object.
The update document must have only field-update operators in it (e.g. $set).
A hash reference of options may be provided.
Valid options include:
• "arrayFilters" - An array of filter documents that determines which array elements to modify for an
update operation on an array field. Only available for MongoDB servers of version 3.6+.
• "bypassDocumentValidation" - skips document validation, if enabled; this is ignored for MongoDB
servers older than version 3.2.
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
• "upsert" – defaults to false; if true, a new document will be added if one is not found by taking the
filter expression and applying the update document operations to it prior to insertion.
find
$cursor = $coll->find( $filter );
$cursor = $coll->find( $filter, $options );
$cursor = $coll->find({ i => { '$gt' => 42 } }, {limit => 20});
Executes a query with a filter expression and returns a lazy "MongoDB::Cursor" object. (The query is not
immediately issued to the server; see below for details.)
The query can be customized using MongoDB::Cursor methods, or with an optional hash reference of options.
Valid options include:
• "allowPartialResults" - get partial results from a mongos if some shards are down (instead of
throwing an error).
• "batchSize" – the number of documents to return per batch.
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "comment" – attaches a comment to the query.
• "cursorType" – indicates the type of cursor to use. It must be one of three string values:
'non_tailable' (the default), 'tailable', and 'tailable_await'.
• "hint" – specify an index to use <http://docs.mongodb.org/manual/reference/command/count/#specify-
the-index-to-use>; must be a string, array reference, hash reference or Tie::IxHash object.
• "limit" – the maximum number of documents to return.
• "max" – specify the exclusive upper bound for a specific index.
• "maxAwaitTimeMS" – the maximum amount of time for the server to wait on new documents to satisfy a
tailable cursor query. This only applies to a "cursorType" of 'tailable_await'; the option is
otherwise ignored. (Note, this will be ignored for servers before version 3.2.)
• "maxScan" – (DEPRECATED) maximum number of documents or index keys to scan.
• "maxTimeMS" – the maximum amount of time to allow the query to run. (Note, this will be ignored for
servers before version 2.6.)
• "min" – specify the inclusive lower bound for a specific index.
• "modifiers" – (DEPRECATED) a hash reference of dollar-prefixed query modifiers
<http://docs.mongodb.org/manual/reference/operator/query-modifier/> modifying the output or behavior
of a query. Top-level options will always take precedence over corresponding modifiers. Supported
modifiers include $comment, $hint, $maxScan, $maxTimeMS, $max, $min, $orderby, $returnKey,
$showDiskLoc, and $snapshot. Some options may not be supported by newer server versions.
• "noCursorTimeout" – if true, prevents the server from timing out a cursor after a period of
inactivity.
• "projection" - a hash reference defining fields to return. See "limit fields to return
<http://docs.mongodb.org/manual/tutorial/project-fields-from-query-results/>" in the MongoDB
documentation for details.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
• "returnKey" – Only return the index field or fields for the results of the query
<https://docs.mongodb.com/manual/reference/operator/meta/returnKey/>.
• "showRecordId" – modifies the output of a query by adding a field $recordId
<https://docs.mongodb.com/manual/reference/method/cursor.showRecordId/> that uniquely identifies a
document in a collection.
• "skip" – the number of documents to skip before returning.
• "sort" – an ordered document defining the order in which to return matching documents. See the
$orderby documentation <https://docs.mongodb.com/manual/reference/operator/meta/orderby/> for
examples.
For more information, see the Read Operations Overview <http://docs.mongodb.org/manual/core/read-
operations-introduction/> in the MongoDB documentation.
Note, a MongoDB::Cursor object holds the query and does not issue the query to the server until the
result method is called on it or until an iterator method like next is called. Performance will be
better directly on a MongoDB::QueryResult object:
my $query_result = $coll->find( $filter )->result;
while ( my $next = $query_result->next ) {
...
}
find_one
$doc = $collection->find_one( $filter, $projection );
$doc = $collection->find_one( $filter, $projection, $options );
Executes a query with a filter expression and returns a single document.
If a projection argument is provided, it must be a hash reference specifying fields to return. See Limit
fields to return <http://docs.mongodb.org/manual/tutorial/project-fields-from-query-results/> in the
MongoDB documentation for details.
If only a filter is provided or if the projection document is an empty hash reference, all fields will be
returned.
my $doc = $collection->find_one( $filter );
my $doc = $collection->find_one( $filter, {}, $options );
A hash reference of options may be provided as a third argument. Valid keys include:
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "maxTimeMS" – the maximum amount of time in milliseconds to allow the command to run. (Note, this
will be ignored for servers before version 2.6.)
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
• "sort" – an ordered document defining the order in which to return matching documents. If $orderby
also exists in the modifiers document, the sort field overwrites $orderby. See docs for $orderby
<http://docs.mongodb.org/manual/reference/operator/meta/orderby/>.
See also core documentation on querying: <http://docs.mongodb.org/manual/core/read/>.
find_id
$doc = $collection->find_id( $id );
$doc = $collection->find_id( $id, $projection );
$doc = $collection->find_id( $id, $projection, $options );
Executes a query with a filter expression of "{ _id => $id }" and returns a single document.
See the find_one documentation for details on the $projection and $options parameters.
See also core documentation on querying: <http://docs.mongodb.org/manual/core/read/>.
find_one_and_delete
$doc = $coll->find_one_and_delete( $filter );
$doc = $coll->find_one_and_delete( $filter, $options );
Given a filter expression, this deletes a document from the database and returns it as it appeared before
it was deleted.
A hash reference of options may be provided. Valid keys include:
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "maxTimeMS" – the maximum amount of time in milliseconds to allow the command to run. (Note, this
will be ignored for servers before version 2.6.)
• "projection" - a hash reference defining fields to return. See "limit fields to return
<http://docs.mongodb.org/manual/tutorial/project-fields-from-query-results/>" in the MongoDB
documentation for details.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
• "sort" – an ordered document defining the order in which to return matching documents. See docs for
$orderby <http://docs.mongodb.org/manual/reference/operator/meta/orderby/>.
find_one_and_replace
$doc = $coll->find_one_and_replace( $filter, $replacement );
$doc = $coll->find_one_and_replace( $filter, $replacement, $options );
Given a filter expression and a replacement document, this replaces a document from the database and
returns it as it was either right before or right after the replacement. The default is 'before'.
The replacement document must not have any field-update operators in it (e.g. $set).
A hash reference of options may be provided. Valid keys include:
• "bypassDocumentValidation" - skips document validation, if enabled; this is ignored for MongoDB
servers older than version 3.2.
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "maxTimeMS" – the maximum amount of time in milliseconds to allow the command to run.
• "projection" - a hash reference defining fields to return. See "limit fields to return
<http://docs.mongodb.org/manual/tutorial/project-fields-from-query-results/>" in the MongoDB
documentation for details.
• "returnDocument" – either the string 'before' or 'after', to indicate whether the returned document
should be the one before or after replacement. The default is 'before'.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
• "sort" – an ordered document defining the order in which to return matching documents. See docs for
$orderby <http://docs.mongodb.org/manual/reference/operator/meta/orderby/>.
• "upsert" – defaults to false; if true, a new document will be added if one is not found
find_one_and_update
$doc = $coll->find_one_and_update( $filter, $update );
$doc = $coll->find_one_and_update( $filter, $update, $options );
Given a filter expression and a document of update operators, this updates a single document and returns
it as it was either right before or right after the update. The default is 'before'.
The update document must contain only field-update operators (e.g. $set).
A hash reference of options may be provided. Valid keys include:
• "arrayFilters" - An array of filter documents that determines which array elements to modify for an
update operation on an array field. Only available for MongoDB servers of version 3.6+.
• "bypassDocumentValidation" - skips document validation, if enabled; this is ignored for MongoDB
servers older than version 3.2.
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "maxTimeMS" – the maximum amount of time in milliseconds to allow the command to run. (Note, this
will be ignored for servers before version 2.6.)
• "projection" - a hash reference defining fields to return. See "limit fields to return
<http://docs.mongodb.org/manual/tutorial/project-fields-from-query-results/>" in the MongoDB
documentation for details.
• "returnDocument" – either the string 'before' or 'after', to indicate whether the returned document
should be the one before or after replacement. The default is 'before'.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
• "sort" – an ordered document defining the order in which to return matching documents. See docs for
$orderby <http://docs.mongodb.org/manual/reference/operator/meta/orderby/>.
• "upsert" – defaults to false; if true, a new document will be added if one is not found
watch
Watches for changes on this collection-
Perform an aggregation with an implicit initial $changeStream stage and returns a MongoDB::ChangeStream
result which can be used to iterate over the changes in the collection. This functionality is available
since MongoDB 3.6.
my $stream = $collection->watch();
my $stream = $collection->watch( \@pipeline );
my $stream = $collection->watch( \@pipeline, \%options );
while (1) {
# This inner loop will only run until no more changes are
# available.
while (my $change = $stream->next) {
# process $change
}
}
The returned stream will not block forever waiting for changes. If you want to respond to changes over a
longer time use "maxAwaitTimeMS" and regularly call "next" in a loop.
Note: Using this helper method is preferred to manually aggregating with a $changeStream stage, since it
will automatically resume when the connection was terminated.
The optional first argument must be an array-ref of aggregation pipeline
<http://docs.mongodb.org/manual/core/aggregation-pipeline/> documents. Each pipeline document must be a
hash reference. Not all pipeline stages are supported after $changeStream.
The optional second argument is a hash reference with options:
• "fullDocument" - The fullDocument to pass as an option to the $changeStream stage. Allowed values:
"default", "updateLookup". Defaults to "default". When set to "updateLookup", the change
notification for partial updates will include both a delta describing the changes to the document, as
well as a copy of the entire document that was changed from some time after the change occurred.
• "resumeAfter" - The logical starting point for this change stream. This value can be obtained from
the "_id" field of a document returned by "next" in MongoDB::ChangeStream. Cannot be specified
together with "startAtOperationTime"
• "maxAwaitTimeMS" - The maximum number of milliseconds for the server to wait before responding.
• "startAtOperationTime" - A BSON::Timestamp specifying at what point in time changes will start being
watched. Cannot be specified together with "resumeAfter". Plain values will be coerced to
BSON::Timestamp objects.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
See "aggregate" for more available options.
See the manual section on Change Streams <https://docs.mongodb.com/manual/changeStreams/> for general
usage information on change streams.
See the Change Streams specification
<https://github.com/mongodb/specifications/blob/master/source/change-streams.rst> for details on change
streams.
aggregate
@pipeline = (
{ '$group' => { _id => '$state,' totalPop => { '$sum' => '$pop' } } },
{ '$match' => { totalPop => { '$gte' => 10 * 1000 * 1000 } } }
);
$result = $collection->aggregate( \@pipeline );
$result = $collection->aggregate( \@pipeline, $options );
Runs a query using the MongoDB 2.2+ aggregation framework and returns a MongoDB::QueryResult object.
The first argument must be an array-ref of aggregation pipeline
<http://docs.mongodb.org/manual/core/aggregation-pipeline/> documents. Each pipeline document must be a
hash reference.
Note: Some pipeline documents have ordered arguments, such as $sort. Be sure to provide these argument
using Tie::IxHash. E.g.:
{ '$sort' => Tie::IxHash->new( age => -1, posts => 1 ) }
A hash reference of options may be provided. Valid keys include:
• "allowDiskUse" – if, true enables writing to temporary files.
• "batchSize" – the number of documents to return per batch.
• "bypassDocumentValidation" - skips document validation, if enabled. (Note, this will be ignored for
servers before version 3.2.)
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "explain" – if true, return a single document with execution information.
• "maxTimeMS" – the maximum amount of time in milliseconds to allow the command to run. (Note, this
will be ignored for servers before version 2.6.)
• "hint" - An index to use for this aggregation. (Only compatible with servers above version 3.6.) For
more information, see the other aggregate options here:
<https://docs.mongodb.com/manual/reference/command/aggregate/index.html>
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
Note MongoDB 2.6+ added the '$out' pipeline operator. If this operator is used to write aggregation
results directly to a collection, an empty result will be returned. Create a new collection> object to
query the generated result collection. When $out is used, the command is treated as a write operation
and read preference is ignored.
See Aggregation <http://docs.mongodb.org/manual/aggregation/> in the MongoDB manual for more information
on how to construct aggregation queries.
Note The use of aggregation cursors is automatic based on your server version. However, if migrating a
sharded cluster from MongoDB 2.4 to 2.6 or later, you must upgrade your mongod servers first before your
mongos routers or aggregation queries will fail. As a workaround, you may pass "cursor => undef" as an
option.
count_documents
$count = $coll->count_documents( $filter );
$count = $coll->count_documents( $filter, $options );
Returns a count of documents matching a filter expression. To return a count of all documents, use an
empty hash reference as the filter.
NOTE: this may result in a scan of all documents in the collection. For a fast count of the total
documents in a collection see "estimated_document_count" instead.
A hash reference of options may be provided. Valid keys include:
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "hint" – specify an index to use; must be a string, array reference, hash reference or Tie::IxHash
object. (Requires server version 3.6 or later.)
• "limit" – the maximum number of documents to count.
• "maxTimeMS" – the maximum amount of time in milliseconds to allow the command to run. (Note, this
will be ignored for servers before version 2.6.)
• "skip" – the number of documents to skip before counting documents.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
NOTE: When upgrading from the deprecated "count" method, some legacy operators are not supported and must
be replaced:
+-------------+--------------------------------+
| Legacy | Modern Replacement |
+=============+================================+
| $where | $expr (Requires MongoDB 3.6+) |
+-------------+--------------------------------+
| $near | $geoWithin with $center |
+-------------+--------------------------------+
| $nearSphere | $geoWithin with $centerSphere |
+-------------+--------------------------------+
estimated_document_count
$count = $coll->estimated_document_count();
$count = $coll->estimated_document_count($options);
Returns an estimated count of documents based on collection metadata.
NOTE: this method does not support sessions or transactions.
A hash reference of options may be provided. Valid keys include:
• "maxTimeMS" – the maximum amount of time in milliseconds to allow the command to run. (Note, this
will be ignored for servers before version 2.6.)
distinct
$result = $coll->distinct( $fieldname );
$result = $coll->distinct( $fieldname, $filter );
$result = $coll->distinct( $fieldname, $filter, $options );
Returns a MongoDB::QueryResult object that will provide distinct values for a specified field name.
The query may be limited by an optional filter expression.
A hash reference of options may be provided. Valid keys include:
• "collation" - a document defining the collation for this operation. See docs for the format of the
collation document here: <https://docs.mongodb.com/master/reference/collation/>.
• "maxTimeMS" – the maximum amount of time in milliseconds to allow the command to run. (Note, this
will be ignored for servers before version 2.6.)
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
See documentation for the distinct command <http://docs.mongodb.org/manual/reference/command/distinct/>
for details.
rename
$newcollection = $collection->rename("mynewcollection");
Renames the collection. If a collection already exists with the new collection name, this method will
throw an exception.
A hashref of options may be provided.
Valid options include:
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
It returns a new MongoDB::Collection object corresponding to the renamed collection.
drop
$collection->drop;
Deletes a collection as well as all of its indexes.
ordered_bulk
$bulk = $coll->ordered_bulk;
$bulk->insert_one( $doc1 );
$bulk->insert_one( $doc2 );
...
$result = $bulk->execute;
Returns a MongoDB::BulkWrite object to group write operations into fewer network round-trips. This
method creates an ordered operation, where operations halt after the first error. See MongoDB::BulkWrite
for more details.
The method "initialize_ordered_bulk_op" may be used as an alias.
A hash reference of options may be provided.
Valid options include:
• "bypassDocumentValidation" - skips document validation, if enabled; this is ignored for MongoDB
servers older than version 3.2.
unordered_bulk
This method works just like "ordered_bulk" except that the order that operations are sent to the database
is not guaranteed and errors do not halt processing. See MongoDB::BulkWrite for more details.
The method "initialize_unordered_bulk_op" may be used as an alias.
A hash reference of options may be provided.
Valid options include:
• "bypassDocumentValidation" - skips document validation, if enabled; this is ignored for MongoDB
servers older than version 3.2.
bulk_write
$res = $coll->bulk_write( [ @requests ], $options )
This method provides syntactic sugar to construct and execute a bulk operation directly, without using
"initialize_ordered_bulk" or "initialize_unordered_bulk" to generate a MongoDB::BulkWrite object and then
calling methods on it. It returns a MongoDB::BulkWriteResponse object just like the MongoDB::BulkWrite
execute method.
The first argument must be an array reference of requests. Requests consist of pairs of a
MongoDB::Collection write method name (e.g. "insert_one", "delete_many") and an array reference of
arguments to the corresponding method name. They may be given as pairs, or as hash or array references:
# pairs -- most efficient
@requests = (
insert_one => [ { x => 1 } ],
replace_one => [ { x => 1 }, { x => 4 } ],
delete_one => [ { x => 4 } ],
update_many => [ { x => { '$gt' => 5 } }, { '$inc' => { x => 1 } } ],
);
# hash references
@requests = (
{ insert_one => [ { x => 1 } ] },
{ replace_one => [ { x => 1 }, { x => 4 } ] },
{ delete_one => [ { x => 4 } ] },
{ update_many => [ { x => { '$gt' => 5 } }, { '$inc' => { x => 1 } } ] },
);
# array references
@requests = (
[ insert_one => [ { x => 1 } ] ],
[ replace_one => [ { x => 1 }, { x => 4 } ] ],
[ delete_one => [ { x => 4 } ] ],
[ update_many => [ { x => { '$gt' => 5 } }, { '$inc' => { x => 1 } } ] ],
);
Valid method names include "insert_one", "insert_many", "delete_one", "delete_many" "replace_one",
"update_one", "update_many".
An optional hash reference of options may be provided.
Valid options include:
• "bypassDocumentValidation" - skips document validation, if enabled; this is ignored for MongoDB
servers older than version 3.2.
• "ordered" – when true, the bulk operation is executed like "initialize_ordered_bulk". When false, the
bulk operation is executed like "initialize_unordered_bulk". The default is true.
• "session" - the session to use for these operations. If not supplied, will use an implicit session.
For more information see MongoDB::ClientSession
See MongoDB::BulkWrite for more details on bulk writes. Be advised that the legacy Bulk API method names
differ slightly from MongoDB::Collection method names.
AUTHORS
• David Golden <david@mongodb.com>
• Rassi <rassi@mongodb.com>
• Mike Friedman <friedo@friedo.com>
• Kristina Chodorow <k.chodorow@gmail.com>
• Florian Ragwitz <rafl@debian.org>
COPYRIGHT AND LICENSE
This software is Copyright (c) 2020 by MongoDB, Inc.
This is free software, licensed under:
The Apache License, Version 2.0, January 2004
perl v5.34.0 2022-06-30 MongoDB::Collection(3pm)