Using CDBExpression With CDBCriteria In findAll - yii

Question

I am trying to generate and execute the following sql through CActiveRecord:
SELECT * FROM `bucket` `t`
WHERE bkt_user = unhex('A4FF2131E00C4696837689FCAAAC7DD2');
I came up with this:
$uuid = 'A4FF2131E00C4696837689FCAAAC7DD2';
$criteria = new CDbCriteria();
$expression = new CDbExpression(
'unhex(:value)',
array(':value'=>$uuid,));
$criteria->addCondition("bkt_user = :exp");
$criteria->params = array(':exp' => $expression);
$buckets = Bucket::model()->findAll($criteria);
The code executes without error or exception but does not return results as expected. A little debugging revealed that the snippet above generates the following sql:
SELECT * FROM `xpg_bucket` `t` WHERE bkt_user = :exp
and AFAIK only one CDbCommandBuilder::bindValue where :exp is bound to unhex(:value). There is no parameter binding done for :value. This is happening in CDbCommandBuilder::createFindCommand. CDbCommandBuilder::createInsertCommand, on the other hand seems to take care of a value itself being a CDbExpression and generated the appropriate bindValue's.
CDbExpression's documentation contains:
* CDbExpression is mainly used in {#link CActiveRecord} as attribute values.
* When inserting or updating a {#link CActiveRecord}, attribute values of
* type CDbExpression will be directly put into the corresponding SQL statement
* without escaping.
Does this mean CDbExpression is not meant to be used with CDbCriteria in findAll()? If yes, what is the alternative?

Answer 1

Actually, it turns out all that circus is not required. The following works with findAll:
$criteria->addCondition('bkt_user = unhex(:value)');
$criteria->params = array(':value'=>'665730BDEDA7489383E2519DB5DE6D60');
$buckets = Bucket::model()->findAll($criteria);
Be aware that the same will not work with add or update operations.