Question

您好我正在使用PDO DB类连接数据库。但我真的很想知道我是否正确。所有连接设置都很好，但i get error when i run a query

我的目录结构

/root
 /dbops <-- Directory contains `config.php` -->
   /dbfunctions <-- Directory contains `DBclass.php` & `DBFuncts.php` -->

现在config.php的内容是：

define( 'DB_HOST', 'localhost' );
define( 'DB_USERNAME', 'root');
define( 'DB_PASSWORD', '');
define( 'DB_NAME', 'testDB');
define('DB_CHAR', 'utf8');

function __autoload($class){
   $parts = explode('__', $class);
   $path = implode(DIRECTORY_SEPARATOR,$parts);
   require_once $path . '.php';
}

DBclass.php包含：

class dbdunctions__DBclass{
  public $instance = null;
  public function __construct() {}
  final private function __clone() {}

   public static function instance()
   {
        if (self::$instance === null)
        {
          $opt  = array(
            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            PDO::ATTR_EMULATE_PREPARES   => TRUE,
            PDO::ATTR_STATEMENT_CLASS    => array('myPDOStatement'),
           );
            $dsn = 'mysql:host='.DB_HOST.';dbname='.DB_NAME.';
            charset='.DB_CHAR;
            self::$instance = new PDO($dsn, DB_USERNAME, DB_PASSWORD, 
            $opt);
        }
        return self::$instance;
   }
   public static function __callStatic($method, $args) {
    return call_user_func_array(array(self::instance(), $method), $args);
   }
}

class myPDOStatement extends PDOStatement
{
   function execute($data = array())
    {
       parent::execute($data);
       return $this;
    }
}

DBFuncts.php包含以下内容：

class dbfunctions__DBFuncts
{
  protected $_con;
  public function __construct()
  {
    $db = new dbfunctions__DBclass();
    $this->_con = $db->con;
  }

  function gotodb(array $data){
    $result = 
  $this->_con::instance()->prepare($qry)->execute(array(/*parameters*/));
  }
}

现在，当使用$result触发查询时，我会收到以下错误

解析错误： 12行 dbops / dbfunctions / DBFuncts.php 中的语法错误，意外的'::'（T_PAAMAYIM_NEKUDOTAYIM） BR />

请指导。我已经花了2个小时来解决这个问题，然后用Google搜索。

Answer 1

而不是

$this->_con::instance()

你应该能够做到

$this->_con->instance()->prepare($qry)->execute(array(/*parameters*/));

不确定当你输入代码时它是否是一个错字 - 但我注意到在DBclass.php你有类dbdunctions__DBclass - 当然这应该是类dbfunctions__DBclass（）？

此外，您的示例代码中似乎还有其他一些错误......但是让我们一次解决一个问题:)

Answer 2

尝试以这种方式调整。我有一些调整在我的服务器上工作。值得注意的是在__construct()类的dbdunctions__DBclass()中实例化连接，并将$this->_con分配给self::$instance（dbdunctions__DBclass::$instance;）：

class dbdunctions__DBclass
    {
        // Make the instance static
        public  static  $instance = null;

        public  function __construct()
            {
                // Create the static connection in the construct
                $this->init();
            }

        private function init()
            {
                if (self::$instance === null) {
                    $opt  = array(
                                PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
                                PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
                                PDO::ATTR_EMULATE_PREPARES   => TRUE,
                                PDO::ATTR_STATEMENT_CLASS    => array('myPDOStatement'),
                               );

                    self::$instance =   new PDO('mysql:host='.DB_HOST.';dbname='.DB_NAME.'; charset='.DB_CHAR, DB_USERNAME, DB_PASSWORD, $opt);
                }
            }

        final private function __clone()
            {
            }

        public  static  function __callStatic($method, $args)
            {
                return call_user_func_array(array(self::instance(), $method), $args);
            }
    }

class myPDOStatement extends PDOStatement
    {
        public  function execute($data = array())
            {
                parent::execute($data);
                return $this;
            }
    }

class dbfunctions__DBFuncts
    {
        protected $_con;

        public function __construct()
            {
                // Create instance of database
                $database   =   new dbdunctions__DBclass();
                // Assign the connection to the $this->_con
                $this->_con =   dbdunctions__DBclass::$instance;
            }

        public  function gotodb($statement = false,$bind = false)
            {
                // Incase the statement or bind is empty, return 0
                if(empty($statement) || empty($bind))
                    return 0;
                // Create the query with method chain
                $query  =   $this   ->_con->prepare($statement)
                                    ->execute($bind);
                // Fetch results
                while($row = $query->fetch())
                    $result[]   =   $row;
                // If results return array else return 0 for consistency
                return (!empty($result))? $result : 0;
            }
    }

// Instantiate
$dbFunc =   new dbfunctions__DBFuncts();
// Use whatever you use to return a result here. This statement happens
// to work for my database...but likely not yours
print_r($dbFunc->gotodb("select * from `users` where `ID` = :ID",array(":ID"=>"29")));

Answer 3

class dbfunctions__DBFuncts
{
  protected $_con;
  public function __construct()
  {
    $db = new dbfunctions__DBclass();
    $this->db = $db;
  }

  function gotodb(array $data){
    $result = 
  $stmt = $this->db->prepare($qry);
$stmt->execute(array(/*parameters*/));
  }

创建PDO对象，然后将其创建为“成员对象”。 gotodb对象使用“成员对象”PDO实例。以下是我正在处理的网站的代码示例，该代码应该有助于更好地解释它：

    try {
                $sql="
                    SELECT
                          id
                        , name
                        , description
                    FROM    
                        ue_bug_project                  
                ";
// $stmt objected created by preparing the SQL query for execution, using the PDO object, which in this case is $this->db
                $stmt = $this->db->prepare($sql);
// The execute method of the $stmt object is run executing the query, in this case no query data is bound as there is no user submitted data being used
                $stmt->execute();
// The result set is grabbed in one hit and placed into the projects array (I really should have set up the $projects variable as an empty array beforehand)
                $projects = $stmt->fetchAll(PDO::FETCH_ASSOC);
                return $projects;
            }
// If the query fails with an error, the catch block is run, in this case i log the error.
            catch (PDOException $e) {
                error_log('Error when getting the list of projects!');
                error_log(' Query with error: '.$sql);
                error_log(' Reason given:'.$e->getMessage()."\n");
                return false;
            }

}

从代码的外观来看，可能没有必要在PDO类周围放置自己的包装器

PDO连接未按要求工作

3 个答案: