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Home  >  Article  >  Backend Development  >  How to write PHP login function

How to write PHP login function

墨辰丷
墨辰丷Original
2018-06-05 17:50:381425browse

This article mainly introduces how to write the PHP login function. Interested friends can refer to it. I hope it will be helpful to everyone.

The specific code is as follows:

1 login.php
In the login interface, the javascript script uses ajax to asynchronously request dologin.php, which is responsible for user information. Verification (including verification code, PHP generates verification code and can search by yourself). The code of the login interface is as follows: 

<?php session_start();?>
<!DOCTYPE html>
<html>
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
 <title>login</title>
 <link rel="stylesheet" type="text/css" href="CSS/login.css" />
 <script src="JS/ajaxhelper.js" type="text/javascript"></script>
 <script src="JS/jquery-1.3.2.min.js" type="text/javascript"></script>
 <script type="text/javascript">
  function chkForm() {
   if (m$(&#39;username&#39;).value == "") {

    alert(&#39;用户名不能为空.&#39;);
    m$(&#39;username&#39;).focus();
    return false;

   }
   if (m$(&#39;password&#39;).value == "") {

    alert(&#39;密码不能为空.&#39;);
    m$(&#39;password&#39;).focus();
    return false;

   }
   if (m$(&#39;password&#39;).value != "" && m$(&#39;username&#39;).value != "") {

    var xmlhttp = createRequest();
    if (xmlhttp) {
     m$(&#39;loading&#39;).innerHTML = "<font color=&#39;red&#39;>loading...</font>";
     var username = m$(&#39;username&#39;).value;
     var pwd = m$(&#39;password&#39;).value;
     var code = m$(&#39;txtCode&#39;).value;
     var url = "dologin.php";
     xmlhttp.open("POST", url, true);
     xmlhttp.onreadystatechange = ValidateResult;
     xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
     xmlhttp.send("username=" + escape(username) + "&password=" + escape(pwd) + "&code=" + escape(code));

    } else {
     alert(&#39;xmlHttp创建失败.&#39;);

    }

    function ValidateResult() {
     if (xmlhttp.readyState == 4) {
      if (xmlhttp.status == 200) {
       if (xmlhttp.responseText != "") {

        //window.alert(xmlhttp.responseText);
        var obj = eval("(" + xmlhttp.responseText + ")");
        if (obj.result == true) {
         alert("提示:" + obj.info);
         window.location = &#39;index.php&#39;;

        } else {
         alert("错误:" + obj.info);

        }
       } else {
        window.alert("从服务器获取失败");

        window.location.reload();
       }
       m$(&#39;loading&#39;).innerHTML = "";
      }
     }

    }


   }

  }

  function m$(id) {
   return document.getElementById(id);
  }

  function changeCode() {
   var xmlhttp = createRequest();
   if (xmlhttp) {
    m$(&#39;loading&#39;).innerHTML = "<font color=&#39;red&#39;>loading...</font>";
    var dt = new Date().getTime();
    // alert(dt);
    var url = "function/imagecode.php?dummay" + escape(dt);
    xmlhttp.open("GET", url, true);
    xmlhttp.onreadystatechange = ValidateResult;
    xmlhttp.send(null);

   } else {
    alert(&#39;xmlHttp创建失败.&#39;);

   }

   function ValidateResult() {
    if (xmlhttp.readyState == 4) {
     if (xmlhttp.status == 200) {
      var dt = new Date().getTime();
      var url = "function/imagecode.php?dummay" + escape(dt);
      m$(&#39;imgCode&#39;).src = "function/imagecode.php?dummay" + escape(dt);
      m$(&#39;loading&#39;).innerHTML = "";
     }
    }

   }
  }

  function showTool() {
   $(&#39;#pToolTip&#39;).css("display", "block");
  }

  function hideTool() {
   $(&#39;#pToolTip&#39;).css("display", "none");
  }
  window.onload = initPage;

  function initPage() {
   $(&#39;#pToolTip&#39;).css("display", "none");
  }
 </script>
 </head>
 <body>
 <p style="background-color:#2A3F55; height:80px;">
  
 </p>
 <p style="min-height:500px;">
  
  <p class="left">
  
  <p style="margin:120px auto auto auto; height:300px; text-align:left">
   <p style="font-size:26px;color:#2A3F55; text-align:center;">Ajax PHP Demo System
   <img src="Images/appstorm-icon.png" alt="appcation storm image" style="position:relative;top:-18px; left:-12px;         vertical-align:middle; text-align:center;font-size:10px; width:65px; height:46px;"/>
   </p>
   <br/>
   <hr style="border:dashed thin #2A3F55;width:70%; text-align:center;"/>
   <p style="font-size:13px;color:#999999; margin:20px auto 0 auto; padding-left:200px;">
   Author:<a href="#" onmousemove="showTool();" onmouseout="hideTool();">wangming</a>
   </p>
   <p style="font-size:13px;color:#999999;margin:20px auto auto auto; padding-left:200px;">DateTime:2009-9-1</p>
   <p style="font-size:13px;color:#999999;margin:20px auto auto auto; padding-left:200px;">Version:1.0.0</p>
   <p style="font-size:13px;color:#999999;margin:20px auto auto auto; padding-left:200px;">Email:wangmingemail@163.com     </p>
   <p id="pToolTip">
   <img src="Images/ming.jpg" height="86px;"/>
   <span class="authordes">
    <br/>
    姓名:wangming<br/>
    电商06-2<br/>
   </span>
   
   </p>
   
  </p>
  
  </p>
  
  <p class="right">
  
  <form>
   <br/>
   <table class="flogin">
   <tr>
    <td>用户名:</td>
    <td><input type="text" name="username" id="username"/></td>
    <td></td>
   </tr>
   <tr>
    <td>密   码:</td>
    <td><input type="password" name="password" id="password" /></td>
    <td></td>
   </tr>
   <tr>
    <td>验证码:</td>
    <td>
    <input type="text" name="txtCode" id="txtCode" size="12" /> 
    <img src="function/imagecode.php" id="imgCode" alt="image code" height="22px;" style=" vertical-align:bottom;"/>
    </td>
    <td><input type="button" class="btnrefresh" onclick="changeCode();" /></td>
   </tr>
   <tr>
    <td></td>
    <td><input type="button" class="btnlogin" onclick="chkForm();" /></td>
    <td></td>
   </tr>
   <tr>
    <td></td>
    <td><span id="loading"></span></td>
    <td><span id="code"></span></td>
   </tr>
   
   </table>
  </form>
  </p>
  
 </p>
 <p style="background-color:#2A3F55; height:60px; margin:auto 0 0 0; clear:both; text-align:center; line-height:60px; color:#FFFFFF;font-size:12px;">
  ©Copyright 2015.
 </p>
 </body>
</html>

2 ajaxhelper.js

function createRequest() {
 try {
  request = new XMLHttpRequest();
 } catch (tryMS) {
  try {
   request = new ActiveXObject("Msxml2.XMLHTTP");
  } catch (otherMS) {
   try {
    request = new ActiveXObject("Microsoft.XMLHTTP");
   } catch (failed) {
    request = null;
   }
  }
 }
 return request;
}

function getActivatedObject(e) {
 var obj;
 if (!e) {
  // early version of IE
  obj = window.event.srcElement;
 } else if (e.srcElement) {
  // IE 7 or later
  obj = e.srcElement;
 } else {
  // DOM Level 2 browser
  obj = e.target;
 }
 return obj;
}

function addEventHandler(obj, eventName, handler) {
 if (document.attachEvent) {
  obj.attachEvent("on" + eventName, handler);
 } else if (document.addEventListener) {
  obj.addEventListener(eventName, handler, false);
 }
}

3 dologin .php

<?php
 session_start();
 header("Content-type:text/html;charset=gb2312");//防止返回的中文乱码
 $name=$_POST[&#39;username&#39;];
 $pwd=$_POST[&#39;password&#39;];
 $imagecode=$_POST[&#39;code&#39;];
 if(strtoupper($imagecode)==$_SESSION["code"])
 {
  include("conn/conn.php");
  $sql="select studentName,studentPwd from tbstudent where studentId=&#39;".$name."&#39;";
  $result=mysql_query($sql,$conn);
  if($row=mysql_fetch_assoc($result))
  {
   if($pwd==$row[&#39;studentPwd&#39;])
   {
   $_SESSION[&#39;username&#39;]=$row[&#39;studentName&#39;];
   //echo "{&#39;result&#39;:true,&#39;info&#39;:&#39;登陆成功!&#39;,&#39;code&#39;:&#39;".$_SESSION["code"]."&#39;}";
   echo "{&#39;result&#39;:true,&#39;info&#39;:&#39;登陆成功!&#39;}";
   
   }
   else
   {
   echo "{&#39;result&#39;:false,&#39;info&#39;:&#39;密码错误!&#39;}";
   }
  }
  else
  {
   echo "{&#39;result&#39;:false,&#39;info&#39;:&#39;该用户不存在!&#39;}";
  }
 }
 else
 {
  echo "{&#39;result&#39;:false,&#39;info&#39;:&#39;验证码错误!&#39;}";
 }
?>

4 conn.php

<?php
 $conn=$mysql_connect("localhost","root", "");
 mysql_select_db("bbs",$conn);
 mysql_query("SET NAMES GB2312");
 ?>
 5
 <?php
class Users {
 function Users() {
 }
 function checkLogin($username, $userpwd) {
  try {
   mysql_connect("localhost", "root", "123");
   mysql_select_db("studentdb");
   mysql_query("SET NAMES GB2312");
   $sql = "select userid from tbuser where username=&#39;$username&#39; and userpwd=&#39;" . md5(trim($userpwd)) . "&#39;";
   $result = mysql_query($sql);
   if ($result) {
    $arr = mysql_fetch_row($result);
    $uid = $arr[0];
    if ($uid != "") {
     return "true|$uid login ok.$sql";
     mysql_close();
    } else {
     return "false|login failed!$sql";
     mysql_close();
    }
   } else {
    return "false|$result link db failed!";
    mysql_close();
   }
  }
  catch(Exception $ex) {
   return "false|$ex";
   mysql_close();
  }
 }
 function AddUser($name, $pwd) {
  try {
   mysql_connect("localhost", "root", "123");
   mysql_select_db("studentdb");
   mysql_query("set names gb2312");
   $sql0 = mysql_query("select userid from tbuser where username=&#39;$name&#39;");
   $info0 = mysql_fetch_array($sql0);
   $userid = $info0[0];
   if ($info0 != false) {
    return "false | $name is exisis.(id:$userid)";
   }
   $pwd = md5(trim($pwd));
   $query = mysql_query("insert into tbuser(username,userpwd)values(&#39;$name&#39;,&#39;$pwd&#39;)");
   $error = mysql_errno();
   if ($query) {
    return "true | add ok";
   } else {
    return "false | $error";
   }
  }
  catch(Exception $ex) {
   return "false | $ex";
  }
 }
 function DeleteUser($name) {
  mysql_connect("localhost", "root", "123");
  mysql_select_db("studentdb");
  mysql_query("set names gb2312");
  $name = trim($name);
  $sql0 = mysql_query("select userid from tbuser where username=&#39;$name&#39;");
  $info0 = mysql_fetch_array($sql0);
  if ($info0 != false) {
   if (mysql_query("delete from tbuser where username=&#39;$name&#39;")) {
    return "true | delete ok.(id:" . $info0[0] . ")";
   } else {
    return "false | 删除失败";
   }
  } else {
   return "false | 删除失败 $name 不存在";
  }
 }
 function UpdateUser($id, $name, $pwd) {
  if (is_numeric(intval(trim($id)))) {
   if ($id && $name && $pwd) {
    mysql_connect("localhost", "root", "123");
    mysql_select_db("studentdb");
    mysql_query("set names gb2312");
    $pwd = md5(trim($pwd));
    $isexists = mysql_query("select * from tbuser where userid=&#39;$id&#39;");
    if (mysql_fetch_array($isexists)) {
     $sql0 = mysql_query("update tbuser set username=&#39;$name&#39;,userpwd=&#39;$pwd&#39; where userid= $id");
     if ($sql0) {
      return "ture | update ok";
     } else {
      return "false | 更新失败";
     }
    } else {
     return "false | usrid=$id not exists.";
    }
   } else {
    return "false |id=$id name=$name and pwd=$pwd .At least one of them is null.";
   }
  } else {
   return "false | $id is not type of int.";
  }
 }
}
?>

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's study.

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