基于php的用户登录实现（v2版）（持续迭代）

版本说明

数据库连接

登录页面：login.html

登录处理实现：login.php

用户欢迎页面：welcome.php

密码修改页面：change_password.html

修改执行：change_password.php

用户注册页面：register.html

注册执行：DoRegister.php

版本说明

v2实现功能：

数据库连接（*用户匹配）

用户登录（*前后端判断输入是否为空（弹窗））

用户注册（*前后端判断注册用户是否是新/旧用户（弹窗））

欢迎页面（*欢迎用户）

用户密码修改

用户注销（*返回登录页）

数据库连接

基于php的MySQL数据库联动代码模板

属于公有文件，可用文件包含：include 'session_conn.php';

(以下代码都是)

登录页面：login.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>登录</title><style type="text/css">form{position: absolute;top: 20%;left: 39%;     }/* 控制input:name=login的元素居中 */input[name='login']{/* 配置其为块级元素 */width: 173px;display: block;margin-left: 28%;margin-top: 3%;}input[name='register']{/* 配置其为块级元素 */width: 173px;display: block;margin-left: 28%;margin-top: 3%;}  </style><script type="text/javascript">function redirectToPage(){window.location.href = 'register.html';}function checkForm(form){if(form.username.value == "" || form.username.value == null){//表单名.文本域名.value == ""alert("用户名不能为空");form.username.focus();// 验证完用户名后，如果没有填写，会弹出alert提示，并自动把光标定位到username的输入框return false;     }if(form.password.value == "" || form.password.value == null){alert("密码不能为空");form.password.focus();return false;       }return true;}</script>
</head><body>  <form action="login.php" method="post">  <!-- onsubmit事件在表单提交时触发 --><!-- fieldset标签：表单分区/分组--><fieldset><legend>用户登录-php登录系统测试</legend><ul><li><label>用户名：</label><input type="text" name="username"/></li><li><label>密&emsp;码：</label><input type="password" name="password"/></li><label></label><input  type="submit" name="login" value="登录" onclick="checkForm(form)" />                          <input type="button"  name="register" value="注册"  onclick="redirectToPage()"/>                 </ul></fieldset></form>  
</body>
</html>

登录处理实现：login.php

*注释部分用于调测，可忽略。

<?php
include 'session_conn.php';$username = htmlspecialchars($_POST['username']);   //使用这个函数将用户名转为html实体
$password = md5($_POST['password']);  // MD5加密$conn = mysqli_connect($host,$db_username,$db_pwd,$db_name);     //打开一个mysql连接
if(!$conn){die('连接数据库失败！请检查数据库是否开启'.mysqli_connect_error());     //die()输出一条消息并结束脚本
}
else{if(isset($username) && !empty($username)){if(isset($_POST['password']) && !empty($_POST['password'])){$check_query = mysqli_query($conn,"select * from login_user where username = '$username' limit 1");$arr = mysqli_fetch_assoc($check_query);   //获取结果集作为关联数据if($password == $arr['password']){if($arr){$_SESSION['username'] = $username;$_SESSION['id'] = $arr['id'];echo "<script language = 'javascript'>;location = 'welcome.php'</script>";}}else{echo "<script language = 'javascript'>alert('账户或密码错误');location = 'login.html'</script>";}}else{echo "<script language = 'javascript'>alert('请输入密码信息。');location = 'login.html'</script>";}    }else{  echo "<script language = 'javascript'>alert('请完善登录信息！');location = 'login.html'</script>";}} 
//mysqli_free_result($check_query);//释放内存
//mysqli_close($conn);//关闭连接

用户欢迎页面：welcome.php

*注释部分用于调测，可忽略。

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>welcome</title><style>.table{text-align: center;width: 70%;padding: 15px;background-color: skyblue;border: 5px solid green;border-collapse: collapse;margin-left: 17%;}input[type='button']{margin-left: 50%;}.change_password{margin-left: 70%;}</style><script>function redirectToPage(){window.location.href = "login.html";}</script></head><body>
<br/><br/><br/><br/><br/><br/><br/><br/><?php include 'session_conn.php';   //session引入             if(!isset($_SESSION['id'])){ echo "<script language = 'javascript'>alert('请先登录');location='login.html</script>";//echo '登录超时';exit();}else{$username = $_SESSION['username'];$conn = mysqli_connect($host,$db_username,$db_pwd,$db_name);if(!$conn){die("数据库连接失败！请检查数据库是否开启".mysqli_connect_errno());}else{if(isset($_SESSION['username']) && $_SESSION['username'] == true){echo "<h2 class='table'>登录成功，欢迎用户：".$username."</h2>";echo "<a class = 'change_password' href = 'change_password.html'/>修改密码</a>";}else{$_SESSION['username'] = false;die('请登录');}}echo " <input type='button' name='back_login' value='返回登录' onclick='redirectToPage()'/>";echo "<a href = 'close_login.php'/>用户注销</a>";//mysqli_free_result($check_query);    //释放内存//mysqli_close($conn);    //关闭连接      }          ?> 
</body>
</html>

密码修改页面：change_password.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>账户修改</title><style type="text/css">.title{text-align: center;}input[type='password']{margin-left:auto ;}</style><script type="text/javascript">function redirectToPage(){window.location.href='login.html';}function check(form){if(form.OldPassword.value == "" || form.OldPassword.value == null){alert("请输入原密码");form.OldPassword.focus();return false;               }if(form.NewPassword.value == "" || form.NewPassword.value == null){alert("请输入新密码");form.NewPassword.focus();return false;               }if(form.ConfirmNewPassword.value == "" || form.ConfirmNewPassword.value == null){alert("请确认密码");form.ConfirmNewPassword.focus();return false;}return true;}   </script>
</head>
<body><div class="box"><div class="title">change your password</div><form action="change_password.php" method="post">      <table class="change_password"><tr><th>用户名：</th><td><input type="text" name="username"/></td></tr><tr><th>原密码：</th><td><input type="password" name="OldPassword"></td></tr><tr><th>新密码：</th><td><input type="password" name='NewPassword' /></td></tr><tr><th>确认密码:</th><td><input type="password" name="ConfirmNewPassword" /></td></tr></table><input type="submit" name='confirm' value="确认修改"  onclick="check(form)" /><input type="button" name='back' value="返回登录"  onclick="redirectToPage()"/>  </form>
</body>
</html>

修改执行：change_password.php

*注释部分用于调测，可忽略。

<?php
include 'session_conn.php';$change_password=[];$change_password['username'] = htmlspecialchars($_POST['username']);$change_password['old_password'] = md5($_POST['OldPassword']);  $change_password['new_password'] = md5($_POST['NewPassword']);$change_password['confirm_NewPassword'] = md5($_POST['ConfirmNewPassword']);$NewPasswordConn = mysqli_connect($host,$db_username,$db_pwd,$db_name);$Old_password = $_POST['OldPassword'];$New_password = $_POST['NewPassword'];$Confirm_NewPassword = $_POST['ConfirmNewPassword'];$NewPasswordConn = mysqli_connect($host,$db_username,$db_pwd,$db_name);// echo $old_password;if(!$NewPasswordConn){die('数据库连接失败！'.mysqli_connect_error());// echo "数据库连接失败";}else{if(isset($Old_password) && !empty($Old_password)){if(isset($New_password)  && !empty($New_password)){if(isset($Confirm_NewPassword) && !empty($Confirm_NewPassword)){if( $Confirm_NewPassword == $New_password){// $new_password = $change_password['new_password'];$MD5_NewPassword = md5($_POST['NewPassword']);// $username = $change_password['username'];$username = htmlspecialchars($_POST['username']);$sql_update = "update login_user set password = '$MD5_NewPassword' where username = '$username' ";if(mysqli_query($NewPasswordConn,$sql_update)){echo "<script language='javascript'>alert('修改成功，请重新登录！');location='login.html'</script>";}else{echo "<script language='javascript'>alert('密码修改失败，请重新修改！');location='change_password.html'</script>";}}else{echo "<script language='javascript'>alert('密码确认错误');location='change_password.html'</script>";}                   }else{echo "<script language='javascript'>alert('请确认密码！');location = 'change_password.html'</script>";}} else{echo "<script language='javascript'>alert('请输入新密码!');location='change_password.html'</script>";}       }else{echo "<script language='javascript'>alert('请输入原密码信息！');location='change_password.html'</script>";}}   
?>

用户注册页面：register.html

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>新用户注册</title>
</head>
<style type='text/css'>.title{text-align:center;line-height: 8;}.login {display: block;position: absolute;transform: translate(-50%,-61.8%);left: 56%;top:20%;width: 450px;border-radius:8px ;         /*登陆框4个角设置为圆角*/background:rgba(255, 255,255, 0.9);    /*白色背景，不透明度90%  */}input[type='submit']{width: 173px;display: block;margin-left: auto;/* 输入框与表头之间的距离 */margin-top: 3%;}</style>
<script>function redirectToPage(){window.location.href = 'login.html';}
</script><body><div class='box'><div class="title">new user register</div><form action="DoRegister.php"  method="post"><table class="login"><tr><th>用户名：</th><td><input type="text"  name="username" required/></td></tr><tr><th>密码：</th><td><input type="password"  name="password"/></td></tr><tr><th>确认密码：</th><td><input type="password"  name="repassword" /></td></tr><tr><th></th><td><input type="submit"  value="注册完成"/></td><td><input type="button"  value="返回登录" onclick="redirectToPage()"/></td></tr></table></form></div></body>
</html>

注册执行：DoRegister.php

*注释部分用户调测，可忽略。

<?php
// 连接参数
include 'session_conn.php';
$dsn = "$dbms:host=$host;dbname=$db_name";   //$dsn是PDO连接字符串，包括数据库类型、主机名、数据名称和字符集try{$conn = new PDO($dsn,$db_username,$db_pwd);
}
catch(PDOException $e){echo '连接失败'.$e->getMessage();    //getMessage定位详细报错信息
}// 接受前端数据
$data=[];
$data['username'] = htmlspecialchars($_POST['username']);
$username = $data['username'];$data['password'] = md5($_POST['password']); 
//$password= $data['password']; $data['repassword'] = md5($_POST['repassword']);
//$repassword = $data['repassword'];//print_r($data);
$conn = mysqli_connect($host,$db_username,$db_pwd,$db_name);// echo "var_dump(die($data(['password'])))";
// echo "var_dump(die($data(['repassword'])))";// 准备SQL语句
// $sql_select = "select * from login_user where username = '$username';";
$sql_select = "select * from login_user where username = '$username' limit 1";  
$sql_id = "select id from login_user";
// $select = $conn->prepare($sql_select);
// $selelct -> execute();   //执行sql语句
// $arr = $select -> fetch(PDO::FETCH_BOUN  
$result_select = mysqli_query($conn,$sql_select);
//$result_new_id = mysqli_num_rows($result_id);
//$result_new_id = $result_id + 1; if(mysqli_num_rows($result_select) != 0){ echo  "<script language='javascript'>alert('该用户已存在，请更换用户名！');location='register.html'</script>";}else{//先判断是否存在在判断是否为空if(!empty($data['password']) && !empty($data['repassword'])){//die ($data['password']);if($data['repassword'] === $data['password']){    //判断两次密码是否相同$password = $data['repassword'];                    $result_sql_id = mysqli_query($conn,$sql_id);                     $result_id = mysqli_num_rows($result_sql_id);                      $result_new_id = $result_id + 1;                      $sql_insert = "insert into login_user(id,username,password) values('$result_new_id','$username','$password');";if(mysqli_query($conn,$sql_insert)){//echo "注册成功";echo "<script language='javascript'>alert('注册成功请返回登录！');location='login.html'</script>";}else{echo "<script language='javascript'>alert('注册失败请重新注册！');location='register.html'</script>";}//$sql_insert = "insert into login_user valuse(NULL,".$data['username'].",".$dsata['md5(password)'].")";    //插入SQL语句}                //}else{echo "<script language='javascript'>alert('确认密码错误！');location='register.html'</script>";  }                           }else{//echo '密码:'.$data['password']; echo "<script language='javascript'>alert('请完善密码。');location='register.html'</script>";  }      
}

待开发：

用户密码修改 :
基于php的用户登录实现（v2版）（持续迭代）-CSDN博客

用户密码查找

引入sessio机制

CSS样式调整