使用php和mysql创建登录表单[重复]

This question already has an answer here:

这个问题在这里已有答案：

Can I mix MySQL APIs in PHP? 5 answers
我可以在PHP中混合MySQL API吗？ 5个答案

I created an account on 000webhost to create html page that has a login form. But I am facing errors when i try to connect the form to the database.

我在000webhost上创建了一个帐户来创建具有登录表单的html页面。但是当我尝试将表单连接到数据库时，我遇到了错误。

Here is the html code:

这是html代码：

     <html>

   <head>
      <title>Login Page</title>

      <style type = "text/css">
         body {
            font-family:Arial, Helvetica, sans-serif;
            font-size:14px;
         }

         label {
            font-weight:bold;
            width:100px;
            font-size:14px;
         }

         .box {
            border:#666666 solid 1px;
         }
      </style>

   </head>

   <body bgcolor = "#FFFFFF">




      <div align = "center">
         <div style = "width:300px; border: solid 1px #333333; " align = "left">
            <div style = "background-color:#333333; color:#FFFFFF; padding:3px;"><b>Login</b></div>

            <div style = "margin:30px">

               <form method="POST" action="C1.php">
                  <label>UserName  :</label><input type = "text" name = "username" required = "box"/><br /><br />
                  <label>Password  :</label><input type = "password" name = "password" required = "box" /><br/><br />


                  <input type = "submit" name="submit" value = " Login "/><br />

               </form>

               <div style = "font-size:11px; color:#cc0000; margin-top:10px"><?php echo $error; ?></div>

            </div>

         </div>

      </div>
   </body>
</html>

here is my php page

这是我的php页面

       <?php
 session_start();
$servername = "localhost";
$username = "******";
$password = "******";

// Create connection
$database_name = "id2425621_login";
$conn = mysqli_connect($servername, $username, $password, $database_name);

 if (isset($_POST['submit']))
        {     

    $username='king';
    $password='king123';

    $query = mysqli_query($conn, "SELECT * FROM mylogin WHERE username='$username' and password='$password'");
     if (mysqli_num_rows($query) != 0)
    {
     echo "sucess";   
      }
      else
      {
    echo "fail";
    }
    }
    ?>

mysql has a table named mylogin and has the values:

mysql有一个名为mylogin的表，其值为：

INSERT INTO `mylogin`(`username`, `password`) VALUES ('king','king123')

i couldn't connect to the database, appreciate ur help in advance

我无法连接到数据库，提前感谢您的帮助

code updated
代码已更新

2 个解决方案

#1

You need to change this line:

您需要更改此行：

 <input type = "submit" value = " Login "/>

To this:

对此：

 <input type = "submit" name="submit" value = " Login "/>

The if() statement in your php wasn't picking up on $_POST['submit'] because it didn't exist.

你的php中的if（）语句没有在$ _POST ['submit']上获取，因为它不存在。

You're also mixing mysql_ and mysqli_ Everything needs to be mysqli_ given that mysql_ is deprecated and generally considered unsafe.

你也混合了mysql_和mysqli_所有东西都需要是mysqli_，因为mysql_已被弃用，通常被认为是不安全的。

#2

You did not mention about databasae. Your MySqli Connection needs the database parameter.

你没有提到databasae。您的MySqli连接需要数据库参数。

$conn = mysqli_connect($servername, $username, $password);

should be

应该

$database_name = "foo";
        $conn = mysqli_connect($servername, $username, $password, $database_name);

First you can check whether your connection is correct using below code.

首先，您可以使用以下代码检查您的连接是否正确。

    if($conn){
    echo "Success";
    }
else{
    echo "Error Connection";}

AND

和

MySQL Functions should be according to MySQLi

MySQL函数应该根据MySQLi

 $query = mysqli_query($conn, "SELECT * FROM mylogin WHERE username='$username' and password='$password'");
     if (mysqli_num_rows($query) != 0)

#1