$columnlist = preg_grep( '/^img/', array_keys( $this->getFieldNames() ) );
$options = [ 'GROUP BY' => array_merge( [ 'img_user' ], $columnlist ) ];
$columnlist = preg_grep( '/^img/', array_keys( $this->getFieldNames() ) );
$options = [ 'GROUP BY' => array_merge( [ 'img_user' ], $columnlist ) ];