error kolom tidak dikenal

ini cara mengatasinya gimana ya ?

mau tambah data malah muncul peringatan Unknown column 'pelajaran' in 'field listgambar.png

database

<?php
$namafolder="gambar_guru/"; //tempat menyimpan file
/*
$con=mysql_connect("localhost","root","") or die("Gagal");
mysql_select_db("ecommerce")  or die("Gagal");*/
include "../conn.php";

$query_guru = mysql_query("SELECT * FROM guru order by kode_guru desc")or die(mysql_error());
$row_guru = mysql_fetch_array($query_guru);
$totalrow_guru = mysql_num_rows($query_guru);

if ($totalrow_guru > 0) {
  $kodeguru_terakhir = substr($row_guru['kode_guru'], -3);
  $nourut = $kodeguru_terakhir+1;
  $isikodeguru ="S"."00".$nourut;
  }else if ($totalrow_guru ==0){
  $nourut = 1;
  $isikodeguru ="S"."00".$nourut;

  }

if (!empty($_FILES["nama_file"]["tmp_name"]))
{
	$jenis_gambar=$_FILES['nama_file']['type'];
        $kode_guru = $_POST['kode_guru'];
		$nip= $_POST['nip'];
		$nama_guru=$_POST['nama_guru'];
        $kelamin=$_POST['kelamin'];
        $alamat=$_POST['alamat'];
        $no_telepon=$_POST['no_telepon'];
        $username=$_POST['username'];
        $password=$_POST['password'];
        $pelajaran = $_POST['pelajaran'];

	if($jenis_gambar=="image/jpeg" || $jenis_gambar=="image/jpg" || $jenis_gambar=="image/gif" || $jenis_gambar=="image/x-png")
	{
		$gambar = $namafolder . basename($_FILES['nama_file']['name']);
		if (move_uploaded_file($_FILES['nama_file']['tmp_name'], $gambar)) {

   # $ceknis = mysql_query("SELECT * FROM guru where nip=$nip")or die(mysql_error());
   # if (mysql_num_rows($ceknis)>=1) {
   #     echo "<script>alert('Nip tersebut sudah digunakan'); window.location = 'input-guru.php' </script>";
   #     die();
   # }

			$sql="INSERT INTO guru(kode_guru,nip,nama_guru,kelamin,alamat,no_telepon,username,password,gambar,pelajaran) VALUES
            ('$kode_guru','$nip','$nama_guru','$kelamin','$alamat','$no_telepon','$username','$password','$gambar','$pelajaran')";
			$res=mysql_query($sql) or die (mysql_error());
		/**	echo "Gambar berhasil dikirim ke direktori".$gambar;
	       	echo "<p>User Id  : $user_id</p>";
            echo "<p>Username : $username</p>";
            echo "<p>Password : $password</p>";
            echo "<p>Fullname : $fullname</p>";
            echo "<p>Gambar   : $gambar</p>";**/
            echo "<script>alert('Data berhasil dimasukan!'); window.location = 'guru.php'</script>";
		} else {
		   echo "<p>Gambar gagal dikirim</p>";
		}
   } else {
		echo "Jenis gambar yang anda kirim salah. Harus .jpg .gif .png";
   }
} else {
	echo "Anda belum memilih gambar / Gambar Harus dibawah 1MB";