Saving many to many relation

CCActiveRecord

<?php
class CCActiveRecord extends CActiveRecord
{
	/**
	 * @var Boolean when set to true we need to save many to many relation
	 */
	protected $MMRelation = false;
	
	/**
	 * A multidimentional array holding relation data
	 * KEY = related model
	 * VALUE = array of one or more related ids
	 * @var array
	 */
	protected $MMRelationData = array();
	
	
	/**
	 * Inserts a record in many to many relation
	 * @param String $modelName Name of related model
	 * @param array $data one or more ids of related model
	 */
	public function addMMRelation($modelName, $data){
		$this->MMRelation = true;
		$this->MMRelationData[$modelName] = $data;
	}
	
	/**
	 * (non-PHPdoc)
	 * @see CActiveRecord::afterSave()
	 */
	public function afterSave(){
		//check if model has specified any MMRelation
		if($this->MMRelation){
			foreach ($this->MMRelationData as $key => $value){
				
				//key is related model. check i fany such relation is specified
				$relations = $this->relations();
				if(		count($relations) < 1 
					|| !isset($relations[$key]) 
					|| $relations[$key][0]!=self::MANY_MANY){
					Logger::error(__CLASS__.': Relation '.$key.' not found');
				}
				
				$relation = $relations[$key];
				$arr = explode('(', $relation[2]);
				$modelName = $arr[0];
				$arr2 = explode(')', $arr[1]);
				$attributes = explode(',', $arr2[0]);
				
				if(count($value) > 0){
					foreach($value as $val){
						
						Yii::app()->db->createCommand()->insert(
							$modelName, array(
								trim($attributes[0])=>$val,
								trim($attributes[1])=>$this->id,
						));
						
						/* $model = new $$modelName;
						$model->$$attributes[1] = $this->id;
						$model->$$attributes[0] = $val;
						
						//TODO : validate both keys exists in respective tables before saving
						if(!$model->save()){
							Logger::error('Error while storing many to many relation');
						} */
					}
				}
			}
		}
	}
	
}

Department model

<?php

class Department extends CCActiveRecord
{
	/**
	 * @return array relational rules.
	 */
	public function relations()
	{
		// NOTE: you may need to adjust the relation name and the related
		// class name for the relations automatically generated below.
		return array(
				'relUser'=> array(self::HAS_ONE, 'User', 'group_id'),
				//specify your many to many relation 
			  //array(self::MANY_MANY, 'relatedModelName', 'RelationTable(foreignKey, localKey)')
				'user'=>array(self::MANY_MANY, 'User', 'cc_user_group_relation(user_id, group_id)')
		);
	}

}

Testing

<?php

class someController extends Controller
{

	public function actionTest(){
		
		$user = User::model()->findByPk('13');
		
		//you just need to add this line
		$user->addMMRelation('department', array('10'));
		
		//and then normal save
		$user->save();
		
	}
	
}

User model

<?php

class User extends CCActiveRecord
{
	/**
	 * @return array relational rules.
	 */
	public function relations()
	{
		// NOTE: you may need to adjust the relation name and the related
		// class name for the relations automatically generated below.
		return array( 
			//'department'=> array(self::BELONGS_TO, 'Department', 'group_id'),
			//specify your many to many relation 
			//array(self::MANY_MANY, 'relatedModelName', 'RelationTable(foreignKey, localKey)')
			'department'=>array(self::MANY_MANY, 'Department', 'cc_user_group_relation(group_id, user_id)'),
			'profile'=>array(self::HAS_ONE, 'UserProfile', 'id')
		);
	
		
		
	}

}