Yii中对数据库的错误请求？

Question

I need to select from the database values on such a request "select * from prem_message where to_id 12 and del_to 0"? I writed this query but it is incorrect, please correct it by writing:

        $criteria = new CDbCriteria();

        // Select a fields from the database
        $criteria->select='id';
        $criteria->select='from_id';
        $criteria->select='to_id';
        $criteria->select='msg';
        $criteria->select='is_read';
        $criteria->select='from_del';
        $criteria->select='to_del';
        $criteria->select='date';

        // Where to_id == current user id and not delete
        $criteria->condition='to_id=:to';
        $criteria->addCondition('to_del=:del','AND');
        $criteria->params=array(':to'=>Yii::app()->user->id);
        $criteria->params=array(':del'=> 0 );

        $model = Message::model()->findAll($criteria);

Error:

CDbException

CDbCommand failed to execute the SQL statement: SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens. The SQL statement executed was: SELECT date FROM prem_message t WHERE (to_id=:to) AND (to_del=:del)

Answer 1

It should be rewritten as:

    $criteria = new CDbCriteria();

    // Select a fields from the database
    $criteria->select='id, from_id, to_id, msg, is_read, from_del, to_del, date';

    // Where to_id == current user id and not delete
    $criteria->condition='to_id=:to';
    $criteria->addCondition('to_del=:del','AND');
    $criteria->params=array(':to'=>Yii::app()->user->id, ':del'=> 0 );

    $model = Message::model()->findAll($criteria);

It is because if you assign variable few times - new value overrides all previous one.