Relations:how To Find Authors Without Posts?

Yii 1.1 General Discussion
1

in the classic example 1 author has many posts…

How can I create a Cdbcriteria to find authors WITHOUT posts ?

2

I would add an relation to the Post model in the Author model.

Then get al the authors and then in a foreach check if(count($authors->posts) == 0) then add to authorswithzeroposts array.

3

and if I need a cdataprovider to use with a cgridview?

4

Hi,

I think you will find the exact answer in this wiki: http://www.yiiframework.com/wiki/319/searching-and-sorting-by-count-of-related-items-in-cgridview

5

Create a named scope in Author model:




public function scopes()

{

  return array(

	'withNoPosts' => array(

  	'condition' => 'NOT EXISTS (SELECT * FROM post WHERE post.author_id = ' . $this->tableAlias . '.id)',

	),

  );

}

And use it with CDbCriteria, when needed.

Note: I know that it can be optimized using JOIN instead of NOT EXISTS. I just wanted to keep the example simple.