licass
(L R M D)
1
public function actionCreate() {
$model = new Preco();
$this->actionValida();
$cod_casa = Yii::app()->getRequest()->getQuery('cod_casa');
$this->actionCalendar($cod_casa, 0);
// $this->performAjaxValidation($model);
if (isset($_POST['Preco'])) {
$model->attributes = $_POST['Preco'];
$model->validate();
$model->save();
}
$this->redirect(array('casa/view', 'id' => $cod_casa, 'fromP' => '1',));
}
Because you gave it no chance to show errors 
$model->validate() - returns false, no error output,
$model->save() - returns false, no error output,
$this->redirect() - redirects to some page, no error output.
Instead, do this:
if (isset($_POST['Preco'])) {
$model->attributes = $_POST['Preco'];
if ($model->save()) {
// optionally set success flash message
$this->redirect(array('casa/view', 'id' => $cod_casa, 'fromP' => '1',));
} else {
// optionally set error flash message
}
}
$this->render('create');