Provided by: libmongodb-perl_1.8.1-1_amd64 
NAME
MongoDB::Database - A MongoDB Database
VERSION
version v1.8.1
SYNOPSIS
# get a Database object via MongoDB::MongoClient
my $db = $client->get_database("foo");
# get a Collection via the Database object
my $coll = $db->get_collection("people");
# run a command on a database
my $res = $db->run_command([ismaster => 1]);
DESCRIPTION
This class models a MongoDB database. Use it to construct MongoDB::Collection objects. It also provides
the "run_command" method and some convenience methods that use it.
Generally, you never construct one of these directly with "new". Instead, you call "get_database" on a
MongoDB::MongoClient 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 {
$db->run_command( @command )
}
catch {
if ( $_->$_isa("MongoDB::DuplicateKeyError" ) {
...
}
else {
...
}
};
To retry failures automatically, consider using Try::Tiny::Retry.
ATTRIBUTES
name
The name of the database.
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::MongoClient 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::MongoClient 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::MongoClient object.
max_time_ms
Specifies the 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 MongoDB::BSON. It may be
initialized with a hash reference that will be coerced into a new MongoDB::BSON object. By default it
will be inherited from a MongoDB::MongoClient object.
METHODS
list_collections
$result = $coll->list_collections( $filter );
$result = $coll->list_collections( $filter, $options );
Returns a MongoDB::QueryResult object to iterate over collection description documents. These will
contain "name" and "options" keys like so:
use boolean;
{
name => "my_capped_collection",
options => {
capped => true,
size => 10485760,
}
},
An optional filter document may be provided, which cause only collection description documents matching a
filter expression to be returned. See the listCollections command documentation
<http://docs.mongodb.org/manual/reference/command/listCollections/> for more details on filtering for
specific collections.
A hash reference of options may be provided. Valid keys include:
• "batchSize" – the number of documents to return per batch.
• "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.)
collection_names
my @collections = $database->collection_names;
my @collections = $database->collection_names( $filter );
Returns the list of collections in this database.
An optional filter document may be provided, which cause only collection description documents matching a
filter expression to be returned. See the listCollections command documentation
<http://docs.mongodb.org/manual/reference/command/listCollections/> for more details on filtering for
specific collections.
Warning: if the number of collections is very large, this may return a very large result. Either pass an
appropriate filter, or use "list_collections" to iterate over collections instead.
get_collection, coll
my $collection = $database->get_collection('foo');
my $collection = $database->get_collection('foo', $options);
my $collection = $database->coll('foo', $options);
Returns a MongoDB::Collection for the given collection name within this database.
It takes an optional hash reference of options that are passed to the MongoDB::Collection constructor.
The "coll" method is an alias for "get_collection".
get_gridfsbucket, gfs
my $grid = $database->get_gridfsbucket;
my $grid = $database->get_gridfsbucket($options);
my $grid = $database->gfs($options);
This method returns a MongoDB::GridFSBucket object for storing and retrieving files from the database.
It takes an optional hash reference of options that are passed to the MongoDB::GridFSBucket constructor.
See MongoDB::GridFSBucket for more information.
The "gfs" method is an alias for "get_gridfsbucket".
get_gridfs (DEPRECATED)
my $grid = $database->get_gridfs;
my $grid = $database->get_gridfs("fs");
my $grid = $database->get_gridfs("fs", $options);
The MongoDB::GridFS class has been deprecated in favor of the new MongoDB driver-wide standard GridFS
API, available via MongoDB::GridFSBucket and the "get_gridfsbucket"/"gfs" methods.
This method returns a MongoDB::GridFS for storing and retrieving files from the database. Default prefix
is "fs", making "$grid->files" "fs.files" and "$grid->chunks" "fs.chunks".
It takes an optional hash reference of options that are passed to the MongoDB::GridFS constructor.
See MongoDB::GridFS for more information.
drop
$database->drop;
Deletes the database.
run_command
my $output = $database->run_command([ some_command => 1 ]);
my $output = $database->run_command(
[ some_command => 1 ],
{ mode => 'secondaryPreferred' }
);
This method runs a database command. The first argument must be a document with the command and its
arguments. It should be given as an array reference of key-value pairs or a Tie::IxHash object with the
command name as the first key. The use of a hash reference will only reliably work for commands without
additional parameters.
By default, commands are run with a read preference of 'primary'. An optional second argument may
specify an alternative read preference. If given, it must be a MongoDB::ReadPreference object or a hash
reference that can be used to construct one.
It returns the output of the command (a hash reference) on success or throws a MongoDB::DatabaseError
exception if the command fails.
For a list of possible database commands, run:
my $commands = $db->run_command([listCommands => 1]);
There are a few examples of database commands in the "DATABASE COMMANDS" in MongoDB::Examples section.
See also core documentation on database commands: <http://dochub.mongodb.org/core/commands>.
DEPRECATIONS
The methods still exist, but are no longer documented. In a future version they will warn when used,
then will eventually be removed.
• last_error
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) 2018 by MongoDB, Inc.
This is free software, licensed under:
The Apache License, Version 2.0, January 2004
perl v5.26.1 2018-01-18 MongoDB::Database(3pm)