一个PDO类

下面是在网上借鉴的一个PDO类：

 <?php
 class Database{
     private $host = DB_HOST;
     private $user = DB_USER;
     private $pass = DB_PASS;
     private $dbname = DB_NAME;

     private $dbh;
     private $error;

     private $stmt;

         /*
         function __construct
         */
     public function __construct(){
         // set DSN
         $dsn = 'mysql:host='.$this->host.';dbname='.$this->dbname;
         //set options
         $options = array(
             PDO::ATTR_PERSISTENT => true,
             PDO::ATTR_ERRMODE    => PDO::ERRMODE_EXCEPTION
         );
         //create a new PDO instanace
         try{
             $this->dbh = new PDO($dsn,$this->user,$this->pass,$options);
         }
         //catch any errors
         catch(PDOException $e){
             $this->error = $e->getMessage();
         }
     }

         /*
         function query
         */
     public function query($query){
         $this->stmt = $this->dbh->prepare($query);
     }    

         /*
           fucntion bindValue
         */
     public function bind($param,$value,$type){
         if (is_null($type)) {
         switch (true) {
             case is_int($value):
                 $type = PDO::PARAM_INT;
                 break;
             case is_bool($value):
                 $type = PDO::PARAM_BOOL;
                 break;
             case is_null($value):
                 $type = PDO::PARAM_NULL;
                 break;
             default:
                 $type = PDO::PARAM_STR;
         }
     }
     $this->stmt->bindValue($param, $value, $type);
     }    

     /*
       functin execute
     */
     public function execute(){
         return $this->stmt->execute();
     }
     /*
     获得结果集  关联数组
     */
     public function resultset(){
     $this->execute();
     return $this->stmt->fetchAll(PDO::FETCH_ASSOC);
     }

     /* 获得单条数据*/
     public function single(){
         $this->execute();
         return $this->stmt->fetch(PDO::FETCH_ASSOC);
     }

     public function rowCount(){
             return $this->stmt->rowCount();
     }

     public function lastInsertId(){
         return $this->dbh->lastInsertId();
     }

     public function beginTransaction(){
         return $this->dbh->beginTransaction();
     }

     public function endTransaction(){
         return $this->dbh->commit();
     }

     public function cancelTransaction(){
            return $this->dbh->rollBack();
     }

     public function debugDumpParams(){
         return $this->stmt->debugDumpParams();
     }

 }
 ?>

这个类的具体使用：

 try{
      $database = new Database();
      $database->beginTransaction();
      $tm_startt = strtotime($_POST['time_start']);
      $tm_end = strtotime($_POST['time_end']);
      $database->query('insert into gua_user(user_name, user_nicheng, user_type, user_comment,user_created,user_end) values (:user_name, :user_nicheng, :user_type, :user_comment,:user_created,:user_end)');
      $database->bind(':user_name', $_POST['username']);
      $database->bind(':user_nicheng', $_POST['user_nick']);
      $database->bind(':user_type', $_POST['user_type']);
      $database->bind(':user_comment', $_POST['comment']);
      $database->bind(':user_created', $tm_startt);
      $database->bind(':user_end', $tm_end);
      $database->execute();
      //获得影响的行数
      $rows = $database->rowCount();
      //获得本条数据的id
      $id = $database->lastInsertId();
      if($rows<1){
          throw new PDOexception('第一句sql语句执行失败！', '01');
      }
      //产生随机字符串 salt
      $salt = $database->salt();
      $password = md5($_POST['password'].$salt);
      $database->query('insert into gua_salt(uid,salt,password) values (:uid,:salt,:password)');
      $database->bind(':uid',$id);
      $database->bind(':salt',$salt);
      $database->bind(':password',$password);
      $database->execute();
      $rows = $database->rowCount();
      if($rows<1){
          throw new PDOexception('第二句sql语句执行失败！', '02');
      }
      $database->endTransaction();
      }catch(PDOexception $e){
          //如果有异常被抛出 则事务失败 执行事务回滚
          $database->cancelTransaction();
          //输出异常信息
          echo $e->getCode().'-----'.$e->getMessage();
      }

使用事物，注意表的类型要是innodb的。

参考网站：http://culttt.com/2012/10/01/roll-your-own-pdo-php-class/