public function setFetchColumns($columns)
    {
        if (! is_array($columns)) {
            $columns = func_get_args();
        }

        $this->fetchColumns = $columns;

        return $this;
    }
public function setFetchColumns($columns)
    {
        if (! is_array($columns)) {
            $columns = func_get_args();
        }

        $this->fetchColumns = $columns;

        return $this;
    }
public function setFetchColumns ( $ columns ) { if ( ! is_array ( $ columns ) ) { $ columns = func_get_args ( ) ; } $ this -> fetchColumns = $ columns ; return $ this ; }
Set Only fetch columns.

If use {@link Select#setModelForOptions($model)}, on fetch
data from the $model table, only specified columns has be
feched.

Examples: <code>setFetchColumns('title')</code> or
<code>setFetchColumns(['title'])</code> or
<code>setFetchColumns('title', 'position')</code> or
<code>setFetchColumns(['title', 'position'])</code>.

@param string|array $columns

@return $this
Set Only fetch columns .