• NAME
• VERSION
• SYNOPSIS
• DESCRIPTION
• USAGE
  • Error handling
• ATTRIBUTES
  • name
  • read_preference
  • write_concern
  • read_concern
  • max_time_ms
  • bson_codec
• METHODS
  • list_collections
  • collection_names
  • get_collection, coll
  • get_gridfsbucket, gfs
  • get_gridfs (DEPRECATED)
  • drop
  • run_command
• DEPRECATIONS
• AUTHORS
• COPYRIGHT AND LICENSE

NAME

MongoDB::Database - A MongoDB Database

VERSION

version v1.6.1

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 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 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 <[email protected]>

• Rassi <[email protected]>

• Mike Friedman <[email protected]>

• Kristina Chodorow <[email protected]>

• Florian Ragwitz <[email protected]>

COPYRIGHT AND LICENSE

This software is Copyright (c) 2017 by MongoDB, Inc.

This is free software, licensed under:

  The Apache License, Version 2.0, January 2004

                    cpanm MongoDB::Database

                    perl -MCPAN -e shell
                    install MongoDB::Database