diff --git "a/\345\220\264\345\252\233\345\246\202/20220525-PHP\344\274\232\350\257\235\346\212\200\346\234\257.md" "b/\345\220\264\345\252\233\345\246\202/20220525-PHP\344\274\232\350\257\235\346\212\200\346\234\257.md"
new file mode 100644
index 0000000000000000000000000000000000000000..460e4e21e27f43d8d6dad6d28fbbf8b0758dfba8
--- /dev/null
+++ "b/\345\220\264\345\252\233\345\246\202/20220525-PHP\344\274\232\350\257\235\346\212\200\346\234\257.md"
@@ -0,0 +1,328 @@
+# 课堂
+
+```php
+<?php
+session_start();
+$user = $_SESSION['username']?:$_COOKIE['username'];
+// 如果这是一个银行的后台，是不是要判断你有没有登录，是不是管理员
+if(isset($user)  && $user=="admin"){
+    echo "银行管理系统首页";
+    echo "欢迎您：".$user;
+    echo "<a href='logout.php'>注销</a>";
+}else{
+    echo "你还没有登录！<a href='login.html'>马上去登录</a>";
+
+//    header('location:login.html');// 没有登录就直接跳到 登录页
+}
+
+
+
+```
+
+```php
+<?php
+session_start();
+// 假设管理员帐号如下
+$username = 'admin';
+$passwrod = '123654';
+
+if($_POST['username']==$username && $_POST['password']==$passwrod){
+    echo "登录成功！";
+    $_SESSION['username']=$username;
+    if($_POST['auto']=='yes'){
+        setcookie('username',"admin",time()+60*60*24*7);
+    }
+
+
+
+//    header('location:index.php'); 一旦帐号正确就自动跳到首页
+    echo "<a href ='index.php'>返回首页</a>";
+}else{
+    die("登录失败！");
+}
+```
+
+```php
+<?php
+// 注销功能，就是删除session对应的值
+session_start();
+unset($_SESSION['username']);
+setcookie('username','',time()-1);
+echo "注销成功";
+```
+
+
+
+# 作业
+
+```php
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>学生信息登陆页面</title>
+</head>
+<body align="center">
+    <h1>学生信息登陆</h1>
+    <form action="dlcg.php" method="post">
+        <table border="0" cellpadding="" cellspacing="" align="center">
+            <tr>
+                <td>
+                    账号：
+                </td>
+                <td>
+                    <input type="text" name="userid" id="">
+                </td>
+            </tr>
+            <tr>
+                <td>
+                    密码：
+                </td>
+                <td>
+                    <input type="password" name="password" id="">
+                </td>
+            </tr>
+            <tr>
+                <td>
+
+                </td>
+                <td>
+                    <input type="checkbox" name="auto" value="yes"> 3天内自动登陆
+                </td>
+            </tr>
+            <tr>
+                <td>
+                    <input type="submit" value="登陆">
+                </td>
+            </tr>
+        </table>
+    </form>
+    
+    
+    
+    
+<?php
+session_start();
+$userid='123456';
+$password='123456';
+if ($_POST['userid']==$userid && $_POST['password']==$password){
+//    echo "登陆成功";
+    $_SESSION['userid']=$userid;
+    if ($_POST['auto']=='yes'){
+        setcookie('userid',"123456",time()+60*60*3);
+    }
+    header('location:pddl.php');
+
+}else{
+
+    die("登陆失败！");
+}
+
+
+
+
+<?php
+session_start();
+$user = $_SESSION['userid']?:$_COOKIE['userid'];
+if (isset($user) && $user=="123456"){
+    header('location:xsxxsy.php');
+}else{
+    echo "还没有登陆<a href='dl.html'>马上去登陆</a>";
+}
+
+
+
+
+<?php
+session_start();
+unset($_SESSION['userid']);
+setcookie('userid','',time()-1);
+echo "注销成功  <a href='dl.html'>返回登陆页面</a>";
+
+
+
+
+<?php
+error_reporting(  E_ALL ^ E_WARNING);
+$a=mysqli_connect(localhost,root,root,student )
+or die("连接失败，错误：".mysqli_connect_error());
+mysqli_query($a,'set names utf8');
+
+
+
+
+<?php
+include_once('sjkxx.php');
+$sql = "select * from user order by id";
+$result = mysqli_query($a,$sql);
+?>
+
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>学生信息管理系统</title>
+    <script>
+        function del(){
+            if (!window.confirm("确定删除？")){
+                return false;
+            }
+        }
+    </script>
+</head>
+<body>
+<h1>学生信息管理首页</h1>
+<a href="dl.html">切换账号</a>
+<a href='zx.php'>退出登陆</a>
+<table border="1" width="600">
+    <tr>
+        <th>学生编号</th>
+        <th>学生姓名</th>
+        <th>学生成绩</th>
+        <th>操作</th>
+    </tr>
+
+        
+        
+        
+<?php
+    if(!mysqli_num_rows($result)) {
+        echo "<tr align='center'><td colspan='5'>暂无数据！</td></tr>";
+    }else {
+        while ($row = mysqli_fetch_assoc($result)) {
+            ?>
+            <tr align="center">
+                <td><?php echo $row['id'] ?></td>
+                <td><?php echo $row['name'] ?></td>
+                <td><?php echo $row['score'] ?></td>
+                <td><a href="xg.php?id=<?php echo $row['id'] ?>">修改</a>|
+                    <a href="sc.php?id=<?php echo $row['id'] ?>" onclick="return del();">删除</a>
+                </td>
+            </tr>
+            <?php
+        }
+    }
+    ?>
+</table>
+<a href="tj.php">添加学生信息</a>
+</body>
+</html>
+
+        
+        
+        
+<?php
+?>
+<html>
+    <head>
+        <title>添加学生信息</title>
+    </head>
+    <body>
+    <h1>添加学生信息</h1>
+    <form action="tj1.php" method="post">
+        <table border="1" width="300">
+            <tr>
+                <th>学生姓名</th><td><input type="text" name="name"></td>
+            </tr>
+            <tr>
+                <th>成绩</th><td><input type="text" name="score"></td>
+            </tr>
+            <tr>
+                <td colspan="2" align="center"><input type="submit" name='submit' value="提交"> &nbsp;&nbsp;
+                    &nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="取消"></td>
+            </tr>
+        </table>
+        <a href="./xsxxsy.php">返回</a>
+    </body>
+</html>
+
+                        
+                        
+                        
+<?php
+include_once('sjkxx.php');
+if(!isset($_POST['submit'])){
+    die("错误途径！");
+}
+$name=$_POST['name'];
+$score=$_POST['score'];
+$sql = "insert into user (name,score)
+ values ('$name',$score)";
+$ret = mysqli_query($a,$sql);
+if($ret){
+    echo "添加成功！<a href='./xsxxsy.php'>返回首页</a>";
+}else{
+    echo "添加失败！";
+}
+
+
+
+
+<?php
+include_once ("sjkxx.php");
+if(!isset($_GET['id'])){
+    die("错误途径！");
+}
+$id=$_GET['id'];
+$sql = "select * from user where id=$id";
+$result = mysqli_query($a,$sql);
+$row = mysqli_fetch_assoc($result);
+?>
+
+<html>
+    <head>
+        <title>修改学生信息</title>
+    </head>
+    <body>
+    <h1>修改学生信息</h1>
+    <form action="xg1.php" method="post">
+        <table border="1" width="300">
+            <tr>
+                <th>学生姓名</th><td><input type="text" name="name" value="<?php echo $row['name'] ?>"></td>
+            </tr>
+            <tr>
+                <th>学生成绩</th><td><input type="text" name="score" value="<?php echo $row['score'] ?>"></td>
+            </tr>
+            <input type="text" name="id" value="<?php echo $row['id'] ?>" hidden>
+            <tr>
+                <td colspan="2" align="center"><input type="submit" name='submit' value="提交">&nbsp;&nbsp;
+                    &nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="取消">
+                </td>
+            </tr>
+        </table>
+        <a href="./xsxxsy.php">返回</a>
+    </body>
+</html>
+
+                        
+                        
+                        
+<?php
+include_once('sjkxx.php');
+if(!isset($_POST['submit'])){
+    die("错误途径！");
+}
+$id=$_POST['id'];
+$name=$_POST['name'];
+$score=$_POST['score'];
+$sql = "update user set name='$name',score=$score where id=$id";
+$ret = mysqli_query($a,$sql);
+if($ret){
+    echo "修改成功！<a href='./xsxxsy.php'>返回首页</a>";
+}else{
+    echo "修改失败！";
+}
+
+
+
+
+<?php
+include_once('sjkxx.php');
+$id=$_GET['id'];
+$sql = "delete from user where id=$id";
+$ret = mysqli_query($a,$sql);
+if($ret){
+    echo "删除成功！<a href='xsxxsy.php'>返回首页</a>";
+}else{
+    echo "删除失败！";
+}
+```
\ No newline at end of file

+ 账号： +	+ +
+ 密码： +	+ +
+ +	+ 3天内自动登陆 +
+ +