php/www/protected/extensions/YiiMongoDbSuite/doc/input/en/advanced.relations.txt

Title: Relations
Author: Dariusz Górecki <darek.krk@gmail.com>

---

- In NoSQL World Relations are not so obvious as in RDBMS
- Because NoSQL databases are designed for performance, there is no need of defining something more complex than correct use of find() method and indexing for fetching related records
- This is just an *idea/concept/example* you can do things in yours preferred way! this is schema-less world, think different!
- MongoDB Documentation has a clean examples and how-to's for handling relations, *please* read them for better understanding of relations in NoSQL world

# HAS_ONE relation {#hasone}

~~~
[php]
// just define method in yours model class (assume we have client collection, and address collection in client model
public function address()
{
	return Address::model()->findByAttributes(array('attribute_with_client_id'=>$this->primaryKey()));
}
~~~

# BELONGS_TO relation {#belongsto}

~~~
[php]
// define in address model
public function client()
{
	return Client::model()->findByPk($this->attribute_with_client_id);
}
~~~

# HAS_MANY relation {#hasmany}

~~~
[php]


// assume we have clients and orders collection
// define in client:
public function orders()
{
	return Client::model()->findAllByAttributes(array('client_id'=>$this->primaryKey()));
}
~~~

# MANY_MANY relation {#manymany}

As simple as defining reverse HAS_MANY relation in orders model. You can view the Example models for details.