* public static function model($className=__CLASS__)
	 * {
	 *     return parent::model($className);
	 * }
	 * 

*
• BELONGS_TO: e.g. a member belongs to a team;
*
• HAS_ONE: e.g. a member has at most one profile;
*
• HAS_MANY: e.g. a team has many members;
*
• MANY_MANY: e.g. a member has many skills and a skill belongs to a member.
*

	 * 'varName'=>array('relationType', 'className', 'foreignKey', ...additional options)
	 * 

*
• 'select': string|array, a list of columns to be selected. Defaults to '*', meaning all columns. * Column names should be disambiguated if they appear in an expression (e.g. COUNT(relationName.name) AS name_count).
*
• 'condition': string, the WHERE clause. Defaults to empty. Note, column references need to * be disambiguated with prefix 'relationName.' (e.g. relationName.age>20)
*
• 'order': string, the ORDER BY clause. Defaults to empty. Note, column references need to * be disambiguated with prefix 'relationName.' (e.g. relationName.age DESC)
*
• 'with': string|array, a list of child related objects that should be loaded together with this object. * Note, this is only honored by lazy loading, not eager loading.
*
• 'joinType': type of join. Defaults to 'LEFT OUTER JOIN'.
*
• 'alias': the alias for the table associated with this relationship. * It defaults to null, * meaning the table alias is the same as the relation name.
*
• 'params': the parameters to be bound to the generated SQL statement. * This should be given as an array of name-value pairs.
*
• 'on': the ON clause. The condition specified here will be appended * to the joining condition using the AND operator.
*
• 'index': the name of the column whose values should be used as keys * of the array that stores related objects. This option is only available to * HAS_MANY and MANY_MANY relations.
*
• 'scopes': scopes to apply. In case of a single scope can be used like 'scopes'=>'scopeName', * in case of multiple scopes can be used like 'scopes'=>array('scopeName1','scopeName2'). * This option has been available since version 1.1.9.
*

*
• 'group': string, the GROUP BY clause. Defaults to empty. Note, column references need to * be disambiguated with prefix 'relationName.' (e.g. relationName.age). This option only applies to HAS_MANY and MANY_MANY relations.
*
• 'having': string, the HAVING clause. Defaults to empty. Note, column references need to * be disambiguated with prefix 'relationName.' (e.g. relationName.age). This option only applies to HAS_MANY and MANY_MANY relations.
*
• 'limit': limit of the rows to be selected. This option does not apply to BELONGS_TO relation.
*
• 'offset': offset of the rows to be selected. This option does not apply to BELONGS_TO relation.
*
• 'through': name of the model's relation that will be used as a bridge when getting related data. Can be set only for HAS_ONE and HAS_MANY. This option has been available since version 1.1.7.
*

	 * return array(
	 *     'author'=>array(self::BELONGS_TO, 'User', 'author_id'),
	 *     'comments'=>array(self::HAS_MANY, 'Comment', 'post_id', 'with'=>'author', 'order'=>'create_time DESC'),
	 *     'tags'=>array(self::MANY_MANY, 'Tag', 'post_tag(post_id, tag_id)', 'order'=>'name'),
	 * );
	 * 

	 * return array(
	 *     'published'=>array(
	 *           'condition'=>'status=1',
	 *     ),
	 *     'recently'=>array(
	 *           'order'=>'create_time DESC',
	 *           'limit'=>5,
	 *     ),
	 * );
	 * 

	 * $posts=Post::model()->published()->findAll();
	 * $posts=Post::model()->published()->recently()->findAll();
	 * $posts=Post::model()->published()->with('comments')->findAll();
	 * 

	 * $postRecord=Post::model()->findByPk($postID);
	 * $postRecord->attributes=$_POST['post'];
	 * $postRecord->save();
	 * 

	 * $postRecord=Post::model()->findByPk($postID);
	 * $postRecord->saveCounters(array('view_count'=>1));
	 * 

	 * // find all posts together with their author and comments
	 * Post::model()->with('author','comments')->findAll();
	 * // find all posts together with their author and the author's profile
	 * Post::model()->with('author','author.profile')->findAll();
	 * 

	 * Post::model()->with(array(
	 *     'author'=>array('select'=>'id, name'),
	 *     'comments'=>array('condition'=>'approved=1', 'order'=>'create_time'),
	 * ))->findAll();
	 *