Php/docs/mongodb.createdbref

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• MongoDB
• Creates a database reference

MongoDB::createDBRef

(PECL mongo >=0.9.0)

MongoDB::createDBRef — Creates a database reference

Description

public MongoDB::createDBRef ( string $collection , mixed $document_or_id ) : array

This method is a flexible interface for creating database refrences (see MongoDBRef).

Parameters

collection

The collection to which the database reference will point.

document_or_id

If an array or object is given, its _id field will be used as the reference ID. If a MongoId or scalar is given, it will be used as the reference ID.

Return Values

Returns a database reference array.

If an array without an _id field was provided as the document_or_id parameter, NULL will be returned.

Examples

Example #1 MongoDB::createDBRef() example

Example demonstrating how to programatically create a DB reference array from a document.

<?php$articles = $db->articles;$article = array( 'title' => 'Test article', 'description' => 'Test article description');$articles->insert($article);$ref = $db->createDBRef('articles', $article);print_r($article);print_r($ref);?>

The above example will output something similar to:

     Array
     (
         [title] => Test article
         [description] => Test article description
         [_id] => MongoId Object
             (
             )

     )
     Array
     (
         [$ref] => articles
         [$id] => MongoId Object
             (
             )

     )
     

Now the $ref can be stored on another document and retrieved later with MongoDB::getDBRef() or MongoCollection::getDBRef().

Example #2 MongoDB::createDBRef() example

Example demonstrating how to programatically create a DB reference from just an id.

<?php$id = new MongoId('47cc67093475061e3d9536d2');$ref = $db->createDBRef('articles', $id);?>