How can I show two attributes values in one row of dropdownlist through relation in yii2

I have a size table and i am displaying a dropdown list through relation i have fld_id,fld_width,and fld_height in size i want to show the drop down whose value will be the record fld_id and the dropdown will show value like fld_width.‘x’.fld_height

my view code is


		$form->field($model, 'fld_size_id')->dropDownList(ArrayHelper::map(Size::find()->all(), 'fld_id','fld_width'),['style'=>'width:25%;', 'prompt'=>'-Choose a Size-']);


i can only give fld_width or fld_height in map function how can i do this to show the values like

fld_width.' x '.fld_height

try this way:

Size::find()->select(['fld_id', '(fld_width + " x " + fld_height) as fld_width'])->all()

thanks for your suggestion i did it like follow


$sizes = Size::find()->all();

$temp = array();

foreach($sizes as $size){

	$temp[$size['fld_id']]= $size->fld_width ." x ". $size->fld_height;


echo $form->field($model, 'fld_size_id')->dropDownList($temp,['style'=>'width:25%;', 'prompt'=>'-Choose a Size-']);


If that works then Okay.