下面是在网上借鉴的一个PDO类：

1 
     host.';dbname='.$this->dbname; 19         //set options 20         $options = array( 21             PDO::ATTR_PERSISTENT => true, 22             PDO::ATTR_ERRMODE    => PDO::ERRMODE_EXCEPTION     23         ); 24         //create a new PDO instanace 25         try{ 26             $this->dbh = new PDO($dsn,$this->user,$this->pass,$options); 27         } 28         //catch any errors 29         catch(PDOException $e){ 30             $this->error = $e->getMessage(); 31         } 32     } 33  34         /* 35         function query 36         */ 37     public function query($query){ 38         $this->stmt = $this->dbh->prepare($query); 39     }     40  41         /* 42           fucntion bindValue 43         */ 44     public function bind($param,$value,$type){ 45         if (is_null($type)) { 46         switch (true) { 47             case is_int($value): 48                 $type = PDO::PARAM_INT; 49                 break; 50             case is_bool($value): 51                 $type = PDO::PARAM_BOOL; 52                 break; 53             case is_null($value): 54                 $type = PDO::PARAM_NULL; 55                 break; 56             default: 57                 $type = PDO::PARAM_STR; 58         } 59     } 60     $this->stmt->bindValue($param, $value, $type); 61     }     62  63     /* 64       functin execute 65     */   66     public function execute(){ 67         return $this->stmt->execute(); 68     } 69     /* 70     获得结果集  关联数组 71     */ 72     public function resultset(){ 73     $this->execute(); 74     return $this->stmt->fetchAll(PDO::FETCH_ASSOC); 75     } 76  77  78     /* 获得单条数据*/ 79     public function single(){ 80         $this->execute(); 81         return $this->stmt->fetch(PDO::FETCH_ASSOC); 82     } 83      84     public function rowCount(){ 85             return $this->stmt->rowCount(); 86     } 87  88     public function lastInsertId(){ 89         return $this->dbh->lastInsertId(); 90     } 91  92     public function beginTransaction(){ 93         return $this->dbh->beginTransaction(); 94     } 95  96     public function endTransaction(){ 97         return $this->dbh->commit(); 98     } 99 100     public function cancelTransaction(){101            return $this->dbh->rollBack();102     }103 104     public function debugDumpParams(){105         return $this->stmt->debugDumpParams();106     }107 108 }109 ?>

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/