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SESSION实战
index.php
<?phpsession_start();if (isset($_SESSION['phone']) ){ echo '用户'.$_SESSION['phone'].'已登录<br>'; echo '<a href="dispatch.php?a=logout">退出</a>';}else{ echo'<a href="dispatch.php?a=login">请登录</a>';}login.php
<?phpif (isset($_SESSION['phone'])){ echo '<script>alert("不要重复登录");location.assign("index.php");</script>';}?><!doctype html><html lang="en"><head><meta charset="UTF-8"><title>用户登录</title></head><body><h3>用户登录</h3><form action="dispatch.php?a=check" method="post" onsubmit="return isEmpty();"> <p> <label for="phone">手机:</label> <input type="phone" name="phone" id="phone"> </p> <p> <label for="password">密码:</label> <input type="password" name="pwd" id="pwd"> </p> <p> <button>提交</button> </p></form><script> function isEmpty() { var phone = document.getElementById('phone').value; var password = document.getElementById('pwd').value; if (phone.length=== 0 || password.length===0) { alert('手机和密码不能为空'); return false; } }</script></body></html>logout.php
<?php// 必须在用户已经登录的情况下再退出if (isset($_SESSION['phone'])) { session_destroy(); echo '<script>alert("退出成功");location.assign("index.php");</script>';} else { // 要求用户先登录 echo '<script>alert("请先登录");location.assign("login.php");</script>';}connect.php
<?php//这两个方法不再用：// php mysql 5.4以下版本// php mysqli 5.4以上版本////主流方法：// PDO是php data object 的简写 php数据对象//PDO支持不同类型的数据库。PDO是最方便访问数据库的接口////PDO连接//$pdo= new PDO('mysql:host=localhost;dbname=shujuku','root123','root123');//print_r($pdo);//数据库连接参数$db=[ 'type'=>'mysql', 'host'=>'localhost', 'dbname'=>'shujuku', 'username'=>'123456', 'password'=>'123456'];$dsn="{$db['type']}:host={$db['host']};dbname={$db['dbname']}";//echo $dsn;//echo '<hr>';//$pdo = new PDO($dsn,$db['username'],$db['password']);////print_r($pdo);//echo'<hr>';//连接数据库try{ $pdo = new PDO($dsn,$db['username'],$db['password']);}catch (PDOException $e) { die('错误信息:'. $e->getMessage());}//print_r($pdo);//PDO、是PHP系统中的类，我们在自己的php文件里是看不到代码的，只能通过打印查看dispatch.php
<?phpsession_start();include 'connect.php';$a=isset($_GET['a'])?$_GET['a']:'logout';$a=htmlentities(strtolower(trim($a)));switch ($a){ case 'login': include 'login.php'; break; case 'check': include 'check.php'; break; case 'logout': include 'logout.php'; break; case 'index': include 'index.php'; break;}check.php
<?phpif ($_SERVER['REQUEST_METHOD'] === 'POST') { $phone = $_POST['phone']; $pwd = md5($_POST['pwd']); $sql = 'SELECT * FROM `user` WHERE `phone` = :phone AND `pwd` = :pwd LIMIT 1'; $stmt = $pdo->prepare($sql); $stmt->execute(['phone'=>$phone, 'pwd'=> $pwd ]); $user = $stmt->fetch(PDO::FETCH_ASSOC); // 4. 判断验证的结果 if (false === $user) { // 验证失败,返回上一下页面 echo '<script>alert("验证失败");history.back();</script>'; die; } // 验证成功，将用户的信息写到session $_SESSION['phone'] = $user['phone']; echo '<script>alert("登录成功");location.assign("index.php");</script>'; exit;} else { die('请求类型错误');}![]()
PDO操作数据库基本流程
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1.连接数据库
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$pdo = new PDO ($dsn,$username,$password);
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2.执行SQL语句完成数据库操作
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①创建SQL语句对象：$stmt = $pdo ->prepare($sql)
$sql就是增删查改标准语句例如：
$sql = ‘SELECT * FROM movies WHERE cate_id = :cate_id’;
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②执行SQL语句：$stmt->execute（）
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③对执行结果进行处理
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3.销毁PDO对象关闭连接：$pdo=null;
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1.连接数据库———基本实例：
//数据库连接参数
$db=[
‘type’=>’mysql’,
‘host’=>’localhost’,
‘dbname’=>’shujuku’,
‘username’=>’123456’,
‘password’=>’123456’
];
$dsn=”{$db[‘type’]}:host={$db[‘host’]};dbname={$db[‘dbname’]}”;
//连接数据库
try{
$pdo = new PDO($dsn,$db[‘username’],$db[‘password’]);
}
catch (PDOException $e) {
die(‘错误信息:’. $e->getMessage());
}
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2.执行SQL语句完成数据库操作———基本实例：
$sql = ‘INSERT INTO category SET name=:name , alias=:alias’;
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①创建SQL语句对象：
$stmt = $pdo ->prepare($sql)
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②执行SQL语句：
//先绑定：$stmt->bindParam(‘name’,$name,PDO::PARAM_STR);
$stmt ->execute();
也可以这样绑定+执行：$stmt ->execute([‘name’=>$name,’name2’=>$name2]);
