pure SQL in Yii (LEFT JOIN)

Recently I need it to make a LEFT JOIN using Yii. I try with $criteria, but it was impossible (for me). So I came across with a “pure” solution. That was:

public function actionGetListBeneficioSegunAnioProcesoInstancia($anio, $proceso, $instancia) {

    $consulta = Yii::app()->db->createCommand("
        SELECT 
            B.BEN_ID_NUM,
            B.BEN_NOMBRE_TXT,
            CASE WHEN LB.BEN_ID_NUM IS NULL THEN 'false' ELSE 'true' END AS MARCA
        FROM 
            PRM_BENEFICIO_BEN B
        LEFT JOIN
            (
                SELECT
                    BEN_ID_NUM
                FROM
                    ALG_RELACION_PROCESO_REL
                WHERE
                    ANI_ID_NUM = ".$anio."
                    AND PAS_ID_NUM = ".$proceso."
                    AND IAS_ID_NUM = ".$instancia."
                GROUP BY
                    BEN_ID_NUM
            ) LB
        ON
            B.BEN_ID_NUM = LB.BEN_ID_NUM
        WHERE 
            B.BEN_ESTADO_NUM <> 0
        ORDER BY
            B.BEN_NOMBRE_TXT ASC"
    )->queryAll();

    $tupla = array(
        'data' => CJSON::encode($consulta)
    );

    echo CJSON::encode($tupla);
}

So, then I can call this service like this:

http://sbyc.byc.local/nmod/M00ALGRELACIONPROCESOREL/getListBeneficioSegunAnioProcesoInstancia?anio=2018&proceso=428&instancia=273