PDO执行DML 以及DQL语句草稿笔记

<?php 
  try{
     //连接数据库 
	 //$dsn data source name(数据原名称(简称驱动))
	 $dsn = "mysql:host=localhost;dbname=feiyu_PDO";    //feiyu_pdo为数据表名 
	 $username = "root";
	 $password = "root";
	 $pdo = new Pdo($dsn,$username,$password);
	 var_dump($pdo); 

	 //设置字符集 
	 $pdo->query("set names utf8");  //切记 不是UTF-8;
     //准备sql语句 
     //$sql = "select * from user";
	 //$sql = "insert into user(username,password) value('zhang3',123)";
	 //$sql = "update user set username = 'lisi'";
     $sql = "delete from user where id>5";	    
     //发送sql语句 
     //exec      处理DML语句 增删改 
     //query     处理DQL语句	查询 
	 echo $pdo->exec($sql);     //返回受影响行数  
	 //echo $pdo->lastInsertid(); //获取刚刚插入主键id
     //处理sql语句

     //关闭数据库连接
	 $pdo = null;
	}catch(PDOException $e){
		//判断错误 
		echo $e->getMessage();
		echo $e->getCode();
		//var_dump($e->errorInfo);
	} 	 
	echo "continue"; 

<?php 
    try{
	    $pdo = new PDO("mysql:host=localhost;dbname=feiyu_pdo","root","root",array(PDO::ATTR_ERRMODE=>PDO::ERRMODE_EXCEPTION));
		
		$pdo->exec("set names utf8");
		$sql = "select * from user";
		$data = $pdo->query($sql);
		//var_dump($data);
		//exit;
		foreach($data as $user){   //这里$user 是个数据表 开始以为是个对象  如果重新做个user1数据表 当然这里遍历也是$user1;
			var_dump($user);
			echo "<hr/>";
		}
		$pdo = null;
	}catch(PDOException $e){
		echo $e->getMessage();
	}