问在grocery-crud中是否有仅导出两列的选项。我不想导出所有列

EN

$state = $crud->getState();

if ($state == 'export' || $state == 'print') {
    $crud->columns('first_name','last_name','email');
} else {
    $crud->columns('first_name','last_name','email','phone','city','country');
}

function example1()
{
    $crud = new grocery_CRUD();

    $crud->set_table('customers');
    $crud->set_subject('Customer');
    $crud->required_fields('first_name', 'last_name','email');

    $state = $crud->getState();

    if ($state == 'export' || $state == 'print') {
        $crud->columns('first_name','last_name','email');
    } else {
        $crud->columns('first_name','last_name','email','phone','city','country');
    }

    $output = $crud->render();

    $this->_example_output($output);
}