Question

I am looking at YII for the first day, and i’m having some problems trying to work out the relations between some tables.

my table structure is as follows:

Pets:
pet_id
pet_name
….

Pet_Owner_Link
pet_id
owner_id

Owner:
owner_id
owner_name

How would I go about getting all of the pets that belong to an owner? Really struggling to get my head around the AR relations at the moment.

Answer 1

Per this comment by DD.Jarod on the Yii AR documentation page: http://www.yiiframework.com/doc/guide/1.1/en/database.arr#c970

“If you declare a many to many relationship, the order of keys inside the jointable declaration must be ‘my_id, other_id’:

class Post extends CActiveRecord
{
  public function relations()
  {
    return array(
        'categories'=>array(self::MANY_MANY, 'Category',
            'tbl_post_category(post_id, category_id)'),
    );
  }
}
class Category extends CActiveRecord
{
  public function relations()
  {
    return array(
        'Posts'=>array(self::MANY_MANY, 'Post',
            'tbl_post_category(category_id, post_id)'),
    );
  }
}

So your code would look like:

class Owner extends CActiveRecord
{
  public function relations()
  {
    return array(
        'pets'=>array(self::MANY_MANY, 'Pet',
            'tbl_post_category(pet_id, owner_id)'),
    );
  }
}
class Pet extends CActiveRecord
{
  public function relations()
  {
    return array(
        'owners'=>array(self::MANY_MANY, 'Post',
            'tbl_post_category(owner_id, pet_id)'),
    );
  }
}

Your problem may be that your primary keys for Pet and Owner by default should be id (not pet_id / owner_id). Yii may be getting confused if you don’t clarify that your primary keys don’t match the default naming convention / aren’t setup as primary keys in the database. You can specify what your primary key is in a model like this:

public function primaryKey()
{
    return 'owner_id';
}

Finally, you would retrive the information like this:

$owner = Owner::model()->findByPk((int)$id);
foreach($owner->pets as $pet)
{
    print $pet->name;
}