yii2判断数据库字段不为空

yii2判断数据库字段is null，如下：

相关教程推荐：yii框架

示例：

$query = new Query;               $query->select('ID, City,State,StudentName')        ->from('student')                                       ->where(['IsActive' => 1])        ->andWhere(['not', ['City' => null]])        ->andWhere(['not', ['State' => null]])        ->orderBy(['rand()' => SORT_DESC])              ->limit(10);