Yii 条件 - 修改以包含 OR 条件

Yii criteria - modify to include OR Condition

我有以下代码行执行简单查询

if ($this->fulfilled)
   $criteria->addCondition('fulfilled ' . (($this->fulfilled == 1) ? "IS NOT NULL" : "IS NULL"));

如何修改它来执行包含 OR 命令的查询,以便基本上 运行 使用框架而不是原始的查询 SQL

if ($this->fulfilled)
AND (fulfilled is null OR fulfilled = 0)

尝试类似的东西

 $criteriaOr = new CDbCriteria();
    $criteriaOr->addCondition('fulfilled IS NULL', 'OR');
    $criteriaOr->addCondition('fulfilled = 0', 'OR');

然后if($this->fulfielled) {$criteria->mergeWith($criteriaOr);}