Updating and delete Related Models (Relational tables) in Yii

Question

UPDATED
I have two related models i.e. Candidate and Qualifications. They have one to one relationship between them. I am using CActiveForm and want to perform CRUD operation on the relational data. I had been able to insert the data but i am having issues with the update and delete. The function is displaying the $id but that the only thing that is displayed on the page.
CandidateController

public function actionUpdate($id)
{
    echo $id;// this is printing the id on page
    $model = Candidate::model()->findByPk($id);
    $q =  Qualification::model()->findAllByAttributes(array('candidate_id' => $id));
    if (isset($_POST['Candidate'], $_POST['Qualification'])) {
        $model->attributes=$_POST['Candidate'];
        $q->attributes=$_POST['Qualification'];

        $error = false;
        $transaction = Yii::app()->db->beginTransaction();
        try {
            if (!$model->save()) {
                throw new CException(CHtml::errorSummary($model));
            }
            $q->candidate_id = $model->id;
            if (!$q->save()) {
                throw new CException(CHtml::errorSummary($q));
                echo $error;
            }
            $transaction->commit();
        } catch (Exception $e) {
            $transaction->rollBack();
            $error = $e->getMessage();
        }

        if (!$error) {
            $this->redirect(array('view','id'=>$model->id));
        }
    }
}



 public function actionView($id)
    {
        /*$this->render('view',array(
            'model'=>$this->loadModel($id),

        ));*/
        $model = $this->loadModel($id);
        $this->render('view',array(
            'Candidate'=>$model,
            'Qualification'=>Qualification::model()->findAllByAttributes(array('candidate_id' => $id))
    ));
    }

I can't understand how to make the data visible in form with edit option.

Answer 1

UPDATING

It seems, you only have a one-to-one relationship so if that is the case you only have to link $q to the specific qualification:

public function actionUpdate()
   {
    //load model
    $q=&$model->qualifications[0];
    if (isset($_POST['Candidate'], $_POST['Qualification'])) {
        $model->attributes=$_POST['Candidate'];
        $q->attributes=$_POST['Qualification'];

        $error = false;
        $transaction = Yii::app()->db->beginTransaction();
        try {
            if (!$model->save()) {
                throw new CException(CHtml::errorSummary($model));
            }
            if (!$q->save()) {
                throw new CException(CHtml::errorSummary($q));
                echo $error;
            }
            $transaction->commit();
        } catch (Exception $e) {
            $transaction->rollBack();
            $error = $e->getMessage();
        }

        if (!$error) {
            $this->redirect(array('view','id'=>$model->id));
        }
    }

With some tweaks i.e a loop and tabular data input the above code can work for one-to-many.

DELETING

For deletion edit Candidate::beforeDelete() to delete all qualifications linked to it as follows:

public function beforeDelete(){
    foreach($this->qualifications as $q)
        $q->delete();
    return parent::beforeDelete();
}

You should wrap the call to Candidate::delete() in a transaction.