PDO实现用户数据的增删改查

来源：互联网发布：excel 2010 vba编程编辑：程序博客网时间：2024/06/05 12:38

为什么要用PDO？

答：避免因项目更换数据库而造成大量重复劳动的SQL语句重写

PDO对象成员方法主要有哪些？

1.三种PDO的连接数据库的方法：

<?php//$mysqli=new mysqli("localhost","user","password","dbname");//PDO对象初始化try{    //3种PDO的连接数据库方法    //1. $pdo=new PDO("mysql:host=localhost;dbname=myapp","root","");    //2. $pdo=new PDO("uri:mysqlPdo.ini","root","");    //3. $pdo=new PDO("mysqlpdo","root","");    $pdo=new PDO("mysqlpdo","root","");}catch (PDOException $e){    die("fail to connect db".$e->getMessage());}//查看属性$attributes  = array(    "AUTOCOMMIT" ,  "ERRMODE" ,  "CASE" ,  "CLIENT_VERSION" ,  "CONNECTION_STATUS" ,    "ORACLE_NULLS" ,  "PERSISTENT" ,  "PREFETCH" ,  "SERVER_INFO" ,  "SERVER_VERSION" ,    "TIMEOUT");foreach ( $attributes  as  $val ) {    echo  "PDO::ATTR_ $val : " ;    echo  $pdo ->getAttribute ( constant ( "PDO::ATTR_ $val " ))."<br/>" ;}//print_r($pdo);

2.PDO实现数据库的增删改查：

<?php/** * 查询数据 *///1.连接数据库try{    $pdo=new PDO("mysql:host=localhost;dbname=myapp","root","");}catch (PDOException $e){    die("fail to connect mysql".$e->getMessage());}//print_r($pdo);//2.执行query(查询)返回一个预处理对象,使用快捷方式$sql="SELECT * FROM users";foreach($pdo->query($sql) as $val){    echo $val['id']."------".$val['name']."------".$val['age']."<br/>";}/** * 添加数据 *///$sql="INSERT INTO users VALUES(null,'Susan','29')";/** * 更新数据 *///$sql="UPDATE users set name='Kill' WHERE id=1";/** * 删除数据 */$sql="DELETE FROM users WHERE id=8";$res=$pdo->exec($sql);if($res){    echo "success";}

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