NAME

       BSON::DBRef - BSON type wrapper for MongoDB DBRefs

VERSION

       version v1.4.0

SYNOPSIS

           use BSON::Types ':all';

           my $dbref = bson_dbref( $oid, $collection_name );

DESCRIPTION

       This module provides a BSON type wrapper for MongoDB Database References
       <http://docs.mongodb.org/manual/reference/database-references/>.

       A DBRef is a special document format which references 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.)

       Use of DBRefs is discouraged, so this module is provided for backwards compatibility.
       "Manual references" <https://docs.mongodb.com/manual/reference/database-
       references/#document-references> are preferred when there is a need to reference other
       documents.

ATTRIBUTES

   id
       Required. The "_id" value of the referenced document. If the "_id" is an ObjectID, then
       you must use a BSON::OID object.

   ref
       Required. The name of 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.

METHODS

   TO_JSON
       If the "BSON_EXTJSON" option is true, returns a hashref compatible with MongoDB's extended
       JSON <https://docs.mongodb.org/manual/reference/mongodb-extended-json/> format, which
       represents it as a document as follows:

           { "$ref": "<collection name>", "$id": "<id>" }

       If the "BSON_EXTJSON" option is false, an error is thrown, as this value can't otherwise
       be represented in JSON.

AUTHORS

       •   David Golden <david@mongodb.com>

       •   Stefan G. <minimalist@lavabit.com>

COPYRIGHT AND LICENSE

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

       This is free software, licensed under:

         The Apache License, Version 2.0, January 2004