Cdbcriteria::$Having - Parameters Escaping?

Hi Everybody,

I have quick question regarding CDbCriteria model.

I need to make simple list of purchases (| total price | list of items |) with filters using CGridView widget.

Part of model's code is as follows:

$criteria = new CDbCriteria;
$criteria->select = array(
    "*",
    "SUM(t.amount) AS amount",
    "GROUP_CONCAT(t.description SEPARATOR ', ') AS description",
);
$criteria->group = 't.payment_id';

And I would like to allow searching by SUM(t.amount), so I added:

$criteria->having = 'amount = ' . (float)$this->amount;

Then I wanted to allow searching by description:

$criteria->having = "description LIKE '%" . $this->description . "%'";    // don't do this at home

Of course above solution is SQL Injection vulnerable, so it cannot be used without escaping parameter first.

My question is - how should I get rid of this issues? Is there any way to escape string "manually"?

Why isn't there any solution like below?

$havingCriteria = new CDbCriteria();
$havingCriteria->compare('description', $this->description, true);
$criteria->having = $havingCriteria;

Regards,
KS