Php 错误：未知列''；在'；字段列表'；MySQL错误

我无法插入数据。错误是：

错误：“字段列表”中的未知列“”

这是一个简单的HTML表单页面，用户将数据插入数据库数据库。 确实需要帮助。我无法得到错误的东西。我是个新手

<?php
$con=mysqli_connect("localhost", "root", "root","dB");
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

$enrollno=$_POST['enrollno'];
$fname=$_POST['fname'];
$lname=$_POST['lname'];
$fathername=$_POST['fathername'];
$coursename=$_POST['coursename'];
$yearsem=$_POST['yearsem'];
$facultyno=$_POST['facultyno'];
$hostel=$_POST['hostel'];
$roomno=$_POST['roomno'];
$email=$_POST['email'];
$mobileno=$_POST['mobileno'];
$peradd=$_POST['peradd'];
$district=$_POST['district'];
$state=$_POST['state'];
$amount=$_POST['amount'];
$pwd=$_POST['pwd'];
$tnc=$_POST['tnc'];

$sql="INSERT INTO registration (enrollno, fname, lname, fathername, coursename, yearsem, facultyno, hostel, roomno, email, mobileno, peradd, district, state, amount, pwd, tnc) VALUES ('$enrollno',`$fname`,`$lname`,`$fathername`,`$coursename`,`$yearsem`,`$facultyno`,`$hostel`,`$roomno`,`$email`,`$mobileno`,`$peradd`,`$district`,`$state`,`$amount`,`$pwd`,'$tnc')";

if (!mysqli_query($con,$sql))
  {
  die('Error: ' . mysqli_error($con));
  }
echo "1 record added";

mysqli_close($con);
?>

您正在对变量使用反勾号[用于列]。使用单引号。请尝试下面的代码

$sql="INSERT INTO registration (enrollno, fname, lname, fathername, coursename, yearsem, facultyno, hostel, roomno, email, mobileno, peradd, district, state, amount, pwd, tnc) VALUES ('$enrollno','$fname','$lname','$fathername','$coursename','$yearsem','$facultyno','$hostel','$roomno','$email','$mobileno','$peradd','$district','$state','$amount','$pwd','$tnc')";

插入到
查询中的值必须用单引号括起来

”而不是反勾号，也不能两者混合使用。反勾号只能用于字段和表名

$sql="INSERT INTO registration (enrollno, fname, lname, fathername, coursename, yearsem, facultyno, hostel, roomno, email, mobileno, peradd, district, state, amount, pwd, tnc) VALUES ('$enrollno','$fname','$lname','$fathername','$coursename','$yearsem','$facultyno','$hostel','$roomno','$email','$mobileno','$peradd','$district','$state','$amount','$pwd','$tnc')";

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旁注：您的代码易受攻击。考虑使用带绑定的参数，而不是将用户输入连接到查询中。

将输入输入到查询完全失败了使用MySQL的要点。准备语句，绑定值，执行。它甚至可以自己解决这个问题。非常感谢。解决了的。你太棒了。但是我仍然无法了解我的代码发生了什么。谢谢你的努力。