Help With Relations

Hi, so here’s my problem.

table 1: equipment with id_equipment. ex: Notebooks, Printers.

table 2: brand with id_brand. ex: Sony, HP.

There’s a many to many relation between these two, so I have another table equipment_brand , with double PRIMARY(id_equipment, id_brand) and foreign keys for the two tables.

Now I have table 3: distributor with id_distributor. ex: 2Net, KLD.

Between the distributor and equipment_brand table, there is also a many to many relation. Which means I have another table 4: distributor_equipment_brand with triple PRIMARY(id_distributor, id_equipment, id_brand) where :

id_distributor foreign to table distributor


(id_equipment, id_brand) double foreign to equipment_brand table

Now, how do I translate this into the relations method of my Distributor model, so that using a downloaded behaviour, the relations are also saved in the triple primary key table.

I would need something like : 'varName' => array(self::MANY_MANY, 'equipment_brand', 'distributor_equipment_brand(id_distributor, array (id_equipment, id_brand))'  );

Why ? Cause I have 2 foreign keys, one of which is double, and references another MANY to MANY table.

That, of course, does not work. Any help ? Or does somebody have an example of using composite foreign keys when defining a self::MANY_MANY variable.

Thank you very much.

Hi tehmaestro,

you could replace the old primary key in equipment_brand by a new, auto-incrementing one and set a unique index to (id_equipment, id_brand).

Depending on how big your application is, this might take a lot of time for refactoring (findByPk -> findByAttributes etc…)

To give you an advice about how to handle your relations with the downloaded behavior I need to know where you downloaded it.

I agree, however that would be pretty difficult to modify, as I would need to shift the primary key of the equipment_brand … many modifications would follow.

This is the behavior http://www.yiiframework.com/extension/activerecord-relation-behavior/

I think the answer is here http://www.yiiframework.com/doc/api/1.1/CActiveRecord#relations-detail , using composite keys, however, I could not find an example anywhere and I did not managed to create one on my own.

I made it work. I used CSaveRelationsBehavior, which has a method, setRelationRecords that accepts composite keys.

For everyone, here’s how the code looks like.

relations() defined in Distributor table:

'myVar' => array(self::MANY_MANY, 'equipment_brand', 'distributor_equipment_brand(id_distributor, id_equipment, id_brand)')

DistributorController , actionCreate for example:

$model->setRelationRecords('myVar',$data);

      $model->save();

Where $data is an array:

$data = array(array('id_equipment' => 1, 'id_brand' =>2), ... )

Where … means that you can put other foreign keys, that can also be arrays.

Good luck.

The thing is, I had to create a model for the equipment_brand table, which I wanted to avoid, but I don’t see any other way.