编码注册系统

Question

的我明显的不良企图所以我试着去建立一个网站，即时通讯开发一个登录系统，我非常新的PHP所以我跳进深结束了一下。我的目标是创建一个注册表单，如果密码不匹配，它不会添加数据并显示错误，并且如果用户名被占用。我已经找到了这两个代码，但我不确定如何一起实现它们。

<?php 
$dbhost = "localhost"; 
$dbuser = "root"; 
$dbpass = ""; 
$dbname = "immo"; 

//Connection to the DB 
$con = mysqli_connect($dbhost,$dbuser,$dbpass,$dbname) or die ($dberror1); 

    session_start(); 
    if (isSet($_POST['Register']) && isSet($_POST['Username']) && isSet($_POST['Password']) && $_POST['Username'] != '' && $_POST['Password'] != '') { 
     $Password = $_POST['Password']; 
     $passMD5 = md5($Password); 
     $Username = $_POST['Username']; 
     $q = mysqli_query($con, "SELECT * FROM `users` WHERE `Username`='$Username'"); 
     if (mysqli_num_rows($q) > 0) { 
      echo 'That username is already taken.'; 
     } 
     if ($_POST['Password']!= $_POST['ConfirmPassword']){ 
      echo("Oops! Password did not match! Try again. "); 
     } 
     else{ 
      $qq = mysqli_query($con, "INSERT INTO `users` VALUES ('', '$Username', '$passMD5')"); 
      if ($qq) { 
       echo 'Registered successfully!'; 
      }else 
       echo 'Failed to register.'; 
     } 
    } 
?> 


<form method="post" class="registration_form"> 
    <fieldset> 
<legend>Registration Form </legend> 

<table> 
<tbody> 
<tr> 
    <td class="label"><label for="Username">Username :</label></td> 
    <td class="input"><input type="text" id="Username" name="Username" required/></td> 
    <td class="error"></td> 
</tr> 
<tr> 
    <td class="label"><label for="Fname">First Name :</label></td> 
    <td class="input"><input type="text" id="Firstname" name="Firstname" required/></td> 
    <td class="error"></td> 
</tr> 
<tr> 
    <td class="label"> <label for="Lname">Last Name :</label></td> 
    <td class="input"><input type="text" id="Lastname" name="Lastname" required/></td> 
    <td class="error"></td> 
</tr> 
<tr> 
    <td class="label"><label for="e-mail">E-mail :</label></td> 
    <td class="input"><input type="email" id="Email" name="Email" required/></td> 
    <td class="error"></td> 
</tr> 
<tr> 
    <td class="label"><label for="Password">Password:</label></td> 
    <td class="input"><input type="password" id="Password" name="Password" required/></td> 
    <td class="error"></td> 
</tr> 
<tr> 
    <td class="label"><label for="ConfirmPassword">Confirm Password:</label></td> 
<td class="input"><input type="password" id="ConfirmPassword" name="ConfirmPassword" required/></td> 
    <td class="error"></td> 
</tr> 
<tr> 
    <td><input type="hidden" name="formsubmitted" value="TRUE" /></td> 
    <td><input type="submit" id="Register" value="Register" name="Register" /></td> 
    <td class="error"></td> 
</tr> 
</tbody> 
</table> 
    </fieldset> 
</form> 

Answer 1

不漂亮，但：

<?php 
    session_start(); 
    if (isSet($_POST['Register']) && isSet($_POST['Username']) && isSet($_POST['Password']) && $_POST['Username'] != '' && $_POST['Password'] != '') { 
     $Password = $_POST['Password']; 
     $passMD5 = md5($Password); 
     $Username = $_POST['Username']; 
     $q = mysqli_query($con, "SELECT * FROM `users` WHERE `Username`='$Username'"); 
     if (mysqli_num_rows($q) == 0) {   
      if ($_POST['Password'] == $_POST['ConfirmPassword']){ 
       $qq = mysqli_query($con, "INSERT INTO `users` VALUES ('', '$Username', '$passMD5')"); 
       if ($qq) { 
        echo 'Registered successfully!'; 
       } else { 
        echo 'Failed to register.'; 
       } 
      } else { 
       echo "Oops! Password did not match! Try again."; 
      } 
     } else { 
      echo 'That username is already taken.'; 
     } 
    } 
?>