function __construct()
 {
     parent::__construct();
     $this->factory = new Student_infoDomainFactory();
     $this->selectStmt = self::$pdo->prepare("SELECT * FROM student_basic_information WHERE open_id=?");
     $this->insertStmt = self::$pdo->prepare("INSERT INTO student_basic_information (open_id,student_id,name,idcard_num,educard_id,school,major,class,entrance_time) VALUES(?,?,?,?,?,?,?,?,?)");
     $this->deleteStmt = self::$pdo->prepare("DELETE FROM student_basic_information WHERE open_id=?");
     $this->updateStmt = self::$pdo->prepare("UPDATE student_basic_information set student_id=?,name=?,idcard_num=?,educard_id=?,school=?,major=?,class=?,entrance_time=? WHERE open_id=?");
     $this->updateAllStmt = self::$pdo->prepare("UPDATE student_basic_information set student_id=?,name=?,idcard_num=?,educard_id=?,school=?,major=?,class=?,entrance_time=? WHERE open_id=?");
 }
 function __construct()
 {
     if (!isset(self::$pdo)) {
         try {
             // 					$dsn="mysql:dbname=afwdb;host=localhost;port=3306";
             // 					$user="******";
             // 					$password="";
             $dsn = "mysql:dbname=afwdb;host=55bcb9ddc1a3f.sh.cdb.myqcloud.com;port=6055";
             $user = "******";
             $password = "******";
             self::$pdo = new PDO($dsn, $user, $password);
             self::$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
         } catch (PDOException $e) {
             print "Error!: " . $e->getMessage() . "<br/>";
             die;
         }
     }
 }