PHP单例模式封装 MySQL-PDO
<?php class MyPDO{ private $type; //数据库类别 private $host; //主机地址 private $port; //端口号 private $dbname; //数据库名 private $charset; //字符集 private $user; //用户名 private $pwd; //密码 private $pdo; //保存PDO对象 private static $instance; private function __construct($param) { $this->initParam($param); $this->initPDO(); $this->initException(); } private function __clone() { } public static function getInstance($param=array()){ if(!self::$instance instanceof self) self::$instance=new self($param); return self::$instance; } //初始化参数 private function initParam($param){ $this->type=$param['type']??'mysql'; $this->host=$param['host']??'127.0.0.1'; $this->port=$param['port']??'3306'; $this->dbname=$param['dbname']??'sel'; $this->charset=$param['charset']??'utf8'; $this->user=$param['user']??'root'; $this->pwd=$param['pwd']??''; } //初始化PDO private function initPDO(){ try{ $dsn="{$this->type}:host={$this->host};port={$this->port};dbname={$this->dbname};charset={$this->charset}"; $this->pdo=new PDO($dsn, $this->user, $this->pwd); } catch (PDOException $ex) { $this->showException($ex); exit; } } //显示异常 private function showException($ex,$sql=''){ if($sql!=''){ echo 'SQL语句执行失败<br>'; echo '错误的SQL语句是:'.$sql,'<br>'; } echo '错误编号:'.$ex->getCode(),'<br>'; echo '错误行号:'.$ex->getLine(),'<br>'; echo '错误文件:'.$ex->getFile(),'<br>'; echo '错误信息:'.$ex->getMessage(),'<br>'; } //设置异常模式 private function initException(){ $this->pdo->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION); } //执行增、删、改操作 public function exec($sql){ try{ return $this->pdo->exec($sql); } catch (PDOException $ex) { $this->showException($ex, $sql); exit; } } //获取自动增长的编号 public function lastInsertId(){ return $this->pdo->lastInsertId(); } //判断匹配的类型 private function fetchType($type){ switch ($type){ case 'num': return PDO::FETCH_NUM; case 'both': return PDO::FETCH_BOTH; case 'obj': return PDO::FETCH_OBJ; default: return PDO::FETCH_ASSOC; } } //获取所有数据 ,返回二维数组 public function fetchAll($sql,$type='assoc'){ try{ $stmt=$this->pdo->query($sql); //获取PDOStatement对象 $type= $this->fetchType($type); //获取匹配方法 return $stmt->fetchAll($type); } catch (Exception $ex) { $this->showException($ex, $sql); } } //获取一维数组 public function fetchRow($sql,$type='assoc'){ try{ $stmt=$this->pdo->query($sql); //获取PDOStatement对象 $type= $this->fetchType($type); //获取匹配方法 return $stmt->fetch($type); } catch (Exception $ex) { $this->showException($ex, $sql); exit; } } //返回一行一列 public function fetchColumn($sql){ try{ $stmt=$this->pdo->query($sql); return $stmt->fetchColumn(); } catch (Exception $ex) { $this->showException($ex, $sql); exit; } } } //测试 $param=array( ); $mypdo= MyPDO::getInstance($param); if($mypdo->exec("insert into news values (null,'11','1111',unix_timestamp())")) echo '自动增长的编号是:'.$mypdo->lastInsertId (); $list=$mypdo->fetchColumn('select count(*) from news'); var_dump($list); ?>