[Yii Framework] About the MANY_MANY

Let say we have three table as:

 

product:
　　id;
　　name;
category:
　　id;
　　name;
category_product:
　　category_id;
　　product_id;

 

 

From their structure we can know that product table and category table are MANY_MANY relation, category_product is the middle table, then how can we get the product records when we have a category.id? 

 

Set the models

Product: 

 代码

class Product extends CActiveRecord
{
    //other codes
    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(
            'categories'=>array(
                self::MANY_MANY,
                'Category',
                'category_product(category_id, product_id)'
            ),
            'category_product'=>array(
                self::HAS_MANY,
                'CategoryProduct',
                'product_id'
            ),
        );
    }
    //other codes
}

 

 Category:

class Category extends CActiveRecord
{
    //other codes
    public function relations()
    {
        return array(
            'products'=>array(
                self::MANY_MANY,
                'Product',
                'category_product(category_id, product_id)',
            ),
            'category_product'=>array(
                self::HAS_MANY,
                'CategoryProduct',
                'category_id',
            ),
        );
    }
    //other codes
}