MongoDB::DBRef(3) A MongoDB database reference

VERSION

version v1.2.3

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

COPYRIGHT AND LICENSE

This software is Copyright (c) 2016 by MongoDB, Inc..

This is free software, licensed under: 

  The Apache License, Version 2.0, January 2004

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