NAME
MongoDB::DBRef - A MongoDB database reference
VERSION
version v1.3.0
SYNOPSIS
my $dbref = MongoDB::DBRef->new(
ref => 'my_collection',
id => 123
);
$coll->insert( { foo => 'bar', other_doc => $dbref } );
DESCRIPTION
This module provides support for database references (DBRefs) in the Perl MongoDB driver. A DBRef is a special embedded document which points to another document in the database. DBRefs are not the same as foreign keys and do not provide any referential integrity or constraint checking. For example, a DBRef may point to a document that no longer exists (or never existed.)
Generally, these are not recommended and "manual references" are preferred.
See "http://docs.mongodb.org/manual/reference/database-references/" in Database references en the MongoDB manual for more information.
ATTRIBUTES
id
Required. The _id
value of the referenced document. If the _id
is an ObjectID, then you must use a MongoDB::OID object.
This may also be specified in the constructor as '$id'
.
ref
Required. The collection in which the referenced document lives. Either a MongoDB::Collection object or a string containing the collection name. The object will be coerced to string form.
This may also be specified in the constructor as '$ref'
.
db
Optional. The database in which the referenced document lives. Either a MongoDB::Database object or a string containing the database name. The object will be coerced to string form.
Not all other language drivers support the $db
field, so using this field is not recommended.
This may also be specified in the constructor as '$db'
.
extra
Optional. A hash reference of additional fields in the DBRef document. Not all MongoDB drivers support this feature and you should not rely on it. This attribute exists solely to ensure DBRefs generated by drivers that do allow extra fields will round-trip correctly.
USE OF THIS FIELD FOR NEW DBREFS IS NOT RECOMMENDED.
AUTHORS
David Golden <david@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) 2015 by MongoDB, Inc..
This is free software, licensed under:
The Apache License, Version 2.0, January 2004