Handling uuid pk column in yii - yii

Question

I'm using UUID's as PK in my tables. They're stored in a BINARY(16) MySQL column. I find that they're being mapped to string type in YII. The CRUD code I generate breaks down though, because these binary column types are being HTML encoded in the views. Example:
<?php echo
CHtml::link(CHtml::encode($data->usr_uuid), /* This is my binary uuid field */
array('view', 'id'=>$data->usr_uuid)); ?>
To work around this problem, I overrode afterFind() and beforeSave() in my model where I convert the values to/from hex using bin2hex and hex2bin respectively. See this for more details.
This takes care of the view problems.
However, now the search on PK when accessing a url of the form:
http://myhost.com/mysite/user/ec12ef8ebf90460487abd77b3f534404
results in User::loadModel($id) being called which in turn calls:
User::model()->findByPk($id);
This doesn't work since the SQL is being generated (on account of it being mapped to php string type) is
select ... where usr_uuid='EC12EF8EBF90460487ABD77B3F534404'
What would have worked is if I could, for these uuid fields change the condition to:
select ... where usr_uuid=unhex('EC12EF8EBF90460487ABD77B3F534404')
I was wondering how I take care of this problem cleanly. I see one possiblity - extend CMysqlColumnSchema and override the necessary methods to special case and handle binary(16) columns as uuid type.
This doesn't seem neat as there's no support for uuid natively either in php (where it is treated as string) or in mysql (where I have it as binary(16) column).
Does anyone have any recommendation?

Answer 1

If you plan using it within your own code then I'd create my own base AR class:
class ActiveRecord extends CActiveRecord
{
// ...
public function findByUUID($uuid)
{
return $this->find('usr_uuid=unhex(:uuid)', array('uuid' => $uuid));
}
}
If it's about using generated code etc. then customizing schema a bit may be a good idea.

Answer 2

I used the following method to make working with uuid (binary(16)) columns using Yii/MySQL possible and efficient. I mention efficient, because I could have just made the column a CHAR(32) or (36) with dashes, but that would really chuck efficient out of the window.
I extended CActiveRecord and added a virtual attribute uuid to it. Also overloaded two of the base class methods getPrimaryKey and setPrimaryKey. With these changes most of Yii is happy.
class UUIDActiveRecord extends CActiveRecord
{
public function getUuid()
{
$pkColumn = $this->primaryKeyColumn;
return UUIDUtils::bin2hex($this->$pkColumn);
}
public function setUuid($value)
{
$pkColumn = $this->primaryKeyColumn;
$this->$pkColumn = UUIDUtils::hex2bin($value);
}
public function getPrimaryKey()
{
return $this->uuid;
}
public function setPrimaryKey($value)
{
$this->uuid = $value;
}
abstract public function getPrimaryKeyColumn();
}
Now I get/set UUID using this virtual attribute:
$model->uuid = generateUUID(); // return UUID as 32 char string without the dashes (-)
The last bit, is about how I search. That is accomplished using:
$criteria = new CDbCriteria();
$criteria->addCondition('bkt_user = unhex(:value)');
$criteria->params = array(':value'=>Yii::app()->user->getId()); //Yii::app()->user->getId() returns id as hex string
$buckets = Bucket::model()->findAll($criteria);
A final note though, parameter logging i.e. the following line in main.php:
'db'=>array(
...
'enableParamLogging' => true,
);
Still doesn't work, as once again, Yii will try to html encode binary data (not a good idea). I haven't found a workaround for it so I have disabled it in my config file.