变量选择的步进功能不起作用

Question

我正在尝试使用R中的create unique_index(:people, [:phone_number) 函数进行变量选择。但它一直出错。 然后我发现现在没有像以前那样的基本step()功能。混合模型的step()包中有一个阶梯函数。

有没有人知道替代功能呢？

以下是错误的屏幕截图：

Answer 1

显然private void OnMenuItemSelected(object sender, SelectedItemChangedEventArgs e) { var item = (SideMenuItem)e.SelectedItem; var page = item.TargetType; if (page == typeof(PageToDisableMenu)) IsGestureEnabled = false; Detail = new NavigationPage((Page)Activator.CreateInstance(page)); IsPresented = false; } （我假设它是你想要使用的函数）被另一个包掩盖（可能是class DB { private static $_instance = null; private $_conn, $_query, $_error = false, $_result, $_count = 0; /** * */ private function __construct() { $servername = Config::get("mysql/host"); $username = Config::get("mysql/username"); $password = Config::get("mysql/password"); $database = Config::get("mysql/db"); $this->_conn = new mysqli($servername, $username, $password, $database); } public static function getInstance() { if(!isset(self::$_instance)){ self::$_instance = new DB; } return self::$_instance; } public function query($sql) { $this->_error = false; if ($this->_query = $this->_conn->query($sql)) { $this->_result = $this->_query->fetch_object(); $this->_count = $this->_query->num_rows; } else { $this->_error = true; } return $this; } private function action($action, $table, $where = array()) { if(count($where) === 3) { $operators = array('=', '>', '<', '>=', '<='); $field = $where[0]; $operator = $where[1]; $value = $where[2]; if(in_array($operator, $operators)) { $sql = "{$action} FROM {$table} WHERE {$field} {$operator} '{$value}'"; if (!$this->query($sql)->error()) { return $this; } } } elseif (count($where) === 0) { $sql = "{$action} FROM {$table}"; if (!$this->query($sql)->error()) { return $this; } } return false; } public function get($table, $where = array()) { return $this->action("SELECT *", $table, $where); } ）。

您是否尝试使用包名？

    $db = DB::getInstance();
    $results1 = $db->get('pages')->results();
    $results2 = $db->get('pages', ["id", "=", 2])->results();

    var_dump($results1); // Returns first row
    var_dump($results2); // Returns second row